@grpc/grpc-js - npm Package Compare versions

Comparing version 1.3.8 to 1.4.0

build/src/call-stream.d.ts

@@ -5,7 +5,7 @@ /// <reference types="node" />
 import { Status } from './constants';
-import { Filter, FilterFactory } from './filter';
-import { FilterStackFactory } from './filter-stack';
+import { Filter } from './filter';
+import { FilterStackFactory, FilterStack } from './filter-stack';
 import { Metadata } from './metadata';
 import { ChannelImplementation } from './channel';
-import { Subchannel } from './subchannel';
+import { SubchannelCallStatsTracker, Subchannel } from './subchannel';
 import { ServerSurfaceCall } from './server-call';
@@ -95,3 +95,3 @@ export declare type Deadline = Date | number;
     credentials: CallCredentials;
-    filterStack: Filter;
+    filterStack: FilterStack;
     private http2Stream;
@@ -120,2 +120,6 @@ private pendingRead;
     private internalError;
+    private configDeadline;
+    private statusWatchers;
+    private streamEndWatchers;
+    private callStatsTracker;
     constructor(methodName: string, channel: ChannelImplementation, options: CallStreamOptions, filterStackFactory: FilterStackFactory, channelCallCredentials: CallCredentials, callNumber: number);
@@ -137,3 +141,4 @@ private outputStatus;
     private handleTrailers;
-    attachHttp2Stream(stream: http2.ClientHttp2Stream, subchannel: Subchannel, extraFilterFactory?: FilterFactory<Filter>): void;
+    private writeMessageToStream;
+    attachHttp2Stream(stream: http2.ClientHttp2Stream, subchannel: Subchannel, extraFilters: Filter[], callStatsTracker: SubchannelCallStatsTracker): void;
     start(metadata: Metadata, listener: InterceptingListener): void;
@@ -149,2 +154,6 @@ private destroyHttp2Stream;
     getHost(): string;
+    setConfigDeadline(configDeadline: Deadline): void;
+    addStatusWatcher(watcher: (status: StatusObject) => void): void;
+    addStreamEndWatcher(watcher: (success: boolean) => void): void;
+    addFilters(extraFilters: Filter[]): void;
     startRead(): void;
@@ -151,0 +160,0 @@ private maybeCloseWrites;

build/src/call-stream.js

@@ -23,3 +23,2 @@ "use strict";
 const constants_1 = require("./constants");
-const filter_stack_1 = require("./filter-stack");
 const metadata_1 = require("./metadata");
@@ -45,2 +44,12 @@ const stream_decoder_1 = require("./stream-decoder");
 }
+function getMinDeadline(deadlineList) {
+    let minValue = Infinity;
+    for (const deadline of deadlineList) {
+        const deadlineMsecs = deadline instanceof Date ? deadline.getTime() : deadline;
+        if (deadlineMsecs < minValue) {
+            minValue = deadlineMsecs;
+        }
+    }
+    return minValue;
+}
 function isInterceptingListener(listener) {
@@ -119,2 +128,6 @@ return (listener.onReceiveMetadata !== undefined &&
         this.internalError = null;
+        this.configDeadline = Infinity;
+        this.statusWatchers = [];
+        this.streamEndWatchers = [];
+        this.callStatsTracker = null;
         this.filterStack = filterStackFactory.createFilter(this);
@@ -129,3 +142,4 @@ this.credentials = channelCallCredentials;
         };
-        if (this.options.parentCall && this.options.flags & constants_1.Propagate.CANCELLATION) {
+        if (this.options.parentCall &&
+            this.options.flags & constants_1.Propagate.CANCELLATION) {
             this.options.parentCall.on('cancelled', () => {
@@ -141,2 +155,3 @@ this.cancelWithStatus(constants_1.Status.CANCELLED, 'Cancelled by parent call');
             const filteredStatus = this.filterStack.receiveTrailers(this.finalStatus);
+            this.statusWatchers.forEach(watcher => watcher(filteredStatus));
             /* We delay the actual action of bubbling up the status to insulate the
@@ -263,2 +278,3 @@ * cleanup code in this class from any errors that may be thrown in the
     handleTrailers(headers) {
+        this.streamEndWatchers.forEach(watcher => watcher(true));
         let headersString = '';
@@ -297,9 +313,9 @@ for (const header of Object.keys(headers)) {
     }
-    attachHttp2Stream(stream, subchannel, extraFilterFactory) {
-        if (extraFilterFactory !== undefined) {
-            this.filterStack = new filter_stack_1.FilterStack([
-                this.filterStack,
-                extraFilterFactory.createFilter(this),
-            ]);
-        }
+    writeMessageToStream(message, callback) {
+        var _a;
+        (_a = this.callStatsTracker) === null || _a === void 0 ? void 0 : _a.addMessageSent();
+        this.http2Stream.write(message, callback);
+    }
+    attachHttp2Stream(stream, subchannel, extraFilters, callStatsTracker) {
+        this.filterStack.push(extraFilters);
         if (this.finalStatus !== null) {
@@ -312,2 +328,3 @@ stream.close(NGHTTP2_CANCEL);
             this.subchannel = subchannel;
+            this.callStatsTracker = callStatsTracker;
             subchannel.addDisconnectListener(this.disconnectListener);
@@ -380,2 +397,3 @@ subchannel.callRef();
                     this.trace('parsed message of length ' + message.length);
+                    this.callStatsTracker.addMessageReceived();
                     this.tryPush(message);
@@ -442,3 +460,3 @@ }
                             else {
-                                if (this.internalError.code === 'ECONNRESET') {
+                                if (this.internalError.code === 'ECONNRESET' || this.internalError.code === 'ETIMEDOUT') {
                                     code = constants_1.Status.UNAVAILABLE;
@@ -476,5 +494,13 @@ details = this.internalError.message;
                 if (err.code !== 'ERR_HTTP2_STREAM_ERROR') {
-                    this.trace('Node error event: message=' + err.message + ' code=' + err.code + ' errno=' + getSystemErrorName(err.errno) + ' syscall=' + err.syscall);
+                    this.trace('Node error event: message=' +
+                        err.message +
+                        ' code=' +
+                        err.code +
+                        ' errno=' +
+                        getSystemErrorName(err.errno) +
+                        ' syscall=' +
+                        err.syscall);
                     this.internalError = err;
                 }
+                this.streamEndWatchers.forEach(watcher => watcher(false));
             });
@@ -492,3 +518,3 @@ if (!this.pendingRead) {
                 try {
-                    stream.write(this.pendingWrite, this.pendingWriteCallback);
+                    this.writeMessageToStream(this.pendingWrite, this.pendingWriteCallback);
                 }
@@ -535,12 +561,10 @@ catch (error) {
     getDeadline() {
+        const deadlineList = [this.options.deadline];
         if (this.options.parentCall && this.options.flags & constants_1.Propagate.DEADLINE) {
-            const parentDeadline = this.options.parentCall.getDeadline();
-            const selfDeadline = this.options.deadline;
-            const parentDeadlineMsecs = parentDeadline instanceof Date ? parentDeadline.getTime() : parentDeadline;
-            const selfDeadlineMsecs = selfDeadline instanceof Date ? selfDeadline.getTime() : selfDeadline;
-            return Math.min(parentDeadlineMsecs, selfDeadlineMsecs);
+            deadlineList.push(this.options.parentCall.getDeadline());
         }
-        else {
-            return this.options.deadline;
+        if (this.configDeadline) {
+            deadlineList.push(this.configDeadline);
         }
+        return getMinDeadline(deadlineList);
     }
@@ -566,2 +590,14 @@ getCredentials() {
     }
+    setConfigDeadline(configDeadline) {
+        this.configDeadline = configDeadline;
+    }
+    addStatusWatcher(watcher) {
+        this.statusWatchers.push(watcher);
+    }
+    addStreamEndWatcher(watcher) {
+        this.streamEndWatchers.push(watcher);
+    }
+    addFilters(extraFilters) {
+        this.filterStack.push(extraFilters);
+    }
     startRead() {
@@ -617,3 +653,3 @@ /* If the stream has ended with an error, we should not emit any more
                 try {
-                    this.http2Stream.write(message.message, cb);
+                    this.writeMessageToStream(message.message, cb);
                 }
@@ -620,0 +656,0 @@ catch (error) {

build/src/channel.d.ts

@@ -6,9 +6,4 @@ import { Deadline, Call, Http2CallStream } from './call-stream';
 import { ServerSurfaceCall } from './server-call';
-export declare enum ConnectivityState {
-    IDLE = 0,
-    CONNECTING = 1,
-    READY = 2,
-    TRANSIENT_FAILURE = 3,
-    SHUTDOWN = 4
-}
+import { ConnectivityState } from './connectivity-state';
+import { ChannelRef } from './channelz';
 /**
@@ -49,2 +44,8 @@ * An interface that represents a communication channel to a server specified
     /**
+     * Get the channelz reference object for this channel. A request to the
+     * channelz service for the id in this object will provide information
+     * about this channel.
+     */
+    getChannelzRef(): ChannelRef;
+    /**
      * Create a call object. Call is an opaque type that is used by the Client
@@ -89,3 +90,10 @@ * class. This function is called by the gRPC library when starting a
     private configSelector;
+    private originalTarget;
+    private channelzRef;
+    private channelzTrace;
+    private callTracker;
+    private childrenTracker;
     constructor(target: string, credentials: ChannelCredentials, options: ChannelOptions);
+    private getChannelzInfo;
+    private trace;
     private callRefTimerRef;
@@ -110,3 +118,4 @@ private callRefTimerUnref;
     watchConnectivityState(currentState: ConnectivityState, deadline: Date | number, callback: (error?: Error) => void): void;
+    getChannelzRef(): ChannelRef;
     createCall(method: string, deadline: Deadline, host: string | null | undefined, parentCall: ServerSurfaceCall | null, propagateFlags: number | null | undefined): Call;
 }

build/src/channel.js

@@ -19,3 +19,3 @@ "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-exports.ChannelImplementation = exports.ConnectivityState = void 0;
+exports.ChannelImplementation = void 0;
 const call_stream_1 = require("./call-stream");
@@ -36,10 +36,4 @@ const channel_credentials_1 = require("./channel-credentials");
 const uri_parser_1 = require("./uri-parser");
-var ConnectivityState;
-(function (ConnectivityState) {
-    ConnectivityState[ConnectivityState["IDLE"] = 0] = "IDLE";
-    ConnectivityState[ConnectivityState["CONNECTING"] = 1] = "CONNECTING";
-    ConnectivityState[ConnectivityState["READY"] = 2] = "READY";
-    ConnectivityState[ConnectivityState["TRANSIENT_FAILURE"] = 3] = "TRANSIENT_FAILURE";
-    ConnectivityState[ConnectivityState["SHUTDOWN"] = 4] = "SHUTDOWN";
-})(ConnectivityState = exports.ConnectivityState || (exports.ConnectivityState = {}));
+const connectivity_state_1 = require("./connectivity-state");
+const channelz_1 = require("./channelz");
 /**
@@ -63,3 +57,3 @@ * See https://nodejs.org/api/timers.html#timers_setinterval_callback_delay_args
         this.options = options;
-        this.connectivityState = ConnectivityState.IDLE;
+        this.connectivityState = connectivity_state_1.ConnectivityState.IDLE;
         this.currentPicker = new picker_1.UnavailablePicker();
@@ -74,2 +68,4 @@ /**
         this.configSelector = null;
+        this.callTracker = new channelz_1.ChannelzCallTracker();
+        this.childrenTracker = new channelz_1.ChannelzChildrenTracker();
         if (typeof target !== 'string') {
@@ -82,9 +78,7 @@ throw new TypeError('Channel target must be a string');
         if (options) {
-            if (typeof options !== 'object' ||
-                !Object.values(options).every((value) => typeof value === 'string' ||
-                    typeof value === 'number' ||
-                    typeof value === 'undefined')) {
-                throw new TypeError('Channel options must be an object with string or number values');
+            if (typeof options !== 'object') {
+                throw new TypeError('Channel options must be an object');
             }
         }
+        this.originalTarget = target;
         const originalTargetUri = uri_parser_1.parseUri(target);
@@ -102,2 +96,5 @@ if (originalTargetUri === null) {
         (_b = (_a = this.callRefTimer).unref) === null || _b === void 0 ? void 0 : _b.call(_a);
+        this.channelzRef = channelz_1.registerChannelzChannel(target, () => this.getChannelzInfo());
+        this.channelzTrace = new channelz_1.ChannelzTrace();
+        this.channelzTrace.addTrace('CT_INFO', 'Channel created');
         if (this.options['grpc.default_authority']) {
@@ -117,3 +114,5 @@ this.defaultAuthority = this.options['grpc.default_authority'];
             createSubchannel: (subchannelAddress, subchannelArgs) => {
-                return this.subchannelPool.getOrCreateSubchannel(this.target, subchannelAddress, Object.assign({}, this.options, subchannelArgs), this.credentials);
+                const subchannel = this.subchannelPool.getOrCreateSubchannel(this.target, subchannelAddress, Object.assign({}, this.options, subchannelArgs), this.credentials);
+                this.channelzTrace.addTrace('CT_INFO', 'Created subchannel or used existing subchannel', subchannel.getChannelzRef());
+                return subchannel;
             },
@@ -125,4 +124,4 @@ updateState: (connectivityState, picker) => {
                 this.callRefTimerUnref();
-                for (const { callStream, callMetadata, callConfig } of queueCopy) {
-                    this.tryPick(callStream, callMetadata, callConfig);
+                for (const { callStream, callMetadata, callConfig, dynamicFilters } of queueCopy) {
+                    this.tryPick(callStream, callMetadata, callConfig, dynamicFilters);
                 }
@@ -135,4 +134,11 @@ this.updateState(connectivityState);
             },
+            addChannelzChild: (child) => {
+                this.childrenTracker.refChild(child);
+            },
+            removeChannelzChild: (child) => {
+                this.childrenTracker.unrefChild(child);
+            }
         };
         this.resolvingLoadBalancer = new resolving_load_balancer_1.ResolvingLoadBalancer(this.target, channelControlHelper, options, (configSelector) => {
+            this.channelzTrace.addTrace('CT_INFO', 'Address resolution succeeded');
             this.configSelector = configSelector;
@@ -151,4 +157,5 @@ /* We process the queue asynchronously to ensure that the corresponding
         }, (status) => {
+            this.channelzTrace.addTrace('CT_WARNING', 'Address resolution failed with code ' + status.code + ' and details "' + status.details + '"');
             if (this.configSelectionQueue.length > 0) {
-                logging_1.trace(constants_1.LogVerbosity.DEBUG, 'channel', 'Name resolution failed for target ' + uri_parser_1.uriToString(this.target) + ' with calls queued for config selection');
+                this.trace('Name resolution failed with calls queued for config selection');
             }
@@ -174,4 +181,16 @@ const localQueue = this.configSelectionQueue;
         ]);
-        logging_1.trace(constants_1.LogVerbosity.DEBUG, 'channel', 'Channel constructed with options ' + JSON.stringify(options, undefined, 2));
+        this.trace('Channel constructed with options ' + JSON.stringify(options, undefined, 2));
     }
+    getChannelzInfo() {
+        return {
+            target: this.originalTarget,
+            state: this.connectivityState,
+            trace: this.channelzTrace,
+            callTracker: this.callTracker,
+            children: this.childrenTracker.getChildLists()
+        };
+    }
+    trace(text, verbosityOverride) {
+        logging_1.trace(verbosityOverride !== null && verbosityOverride !== void 0 ? verbosityOverride : constants_1.LogVerbosity.DEBUG, 'channel', '(' + this.channelzRef.id + ') ' + uri_parser_1.uriToString(this.target) + ' ' + text);
+    }
     callRefTimerRef() {
@@ -181,3 +200,6 @@ var _a, _b, _c, _d;
         if (!((_b = (_a = this.callRefTimer).hasRef) === null || _b === void 0 ? void 0 : _b.call(_a))) {
-            logging_1.trace(constants_1.LogVerbosity.DEBUG, 'channel', 'callRefTimer.ref | configSelectionQueue.length=' + this.configSelectionQueue.length + ' pickQueue.length=' + this.pickQueue.length);
+            this.trace('callRefTimer.ref | configSelectionQueue.length=' +
+                this.configSelectionQueue.length +
+                ' pickQueue.length=' +
+                this.pickQueue.length);
             (_d = (_c = this.callRefTimer).ref) === null || _d === void 0 ? void 0 : _d.call(_c);
@@ -189,9 +211,12 @@ }
         // If the hasRef function does not exist, always run the code
-        if ((!this.callRefTimer.hasRef) || (this.callRefTimer.hasRef())) {
-            logging_1.trace(constants_1.LogVerbosity.DEBUG, 'channel', 'callRefTimer.unref | configSelectionQueue.length=' + this.configSelectionQueue.length + ' pickQueue.length=' + this.pickQueue.length);
+        if (!this.callRefTimer.hasRef || this.callRefTimer.hasRef()) {
+            this.trace('callRefTimer.unref | configSelectionQueue.length=' +
+                this.configSelectionQueue.length +
+                ' pickQueue.length=' +
+                this.pickQueue.length);
             (_b = (_a = this.callRefTimer).unref) === null || _b === void 0 ? void 0 : _b.call(_a);
         }
     }
-    pushPick(callStream, callMetadata, callConfig) {
-        this.pickQueue.push({ callStream, callMetadata, callConfig });
+    pushPick(callStream, callMetadata, callConfig, dynamicFilters) {
+        this.pickQueue.push({ callStream, callMetadata, callConfig, dynamicFilters });
         this.callRefTimerRef();
@@ -206,6 +231,9 @@ }
      */
-    tryPick(callStream, callMetadata, callConfig) {
+    tryPick(callStream, callMetadata, callConfig, dynamicFilters) {
         var _a, _b, _c;
-        const pickResult = this.currentPicker.pick({ metadata: callMetadata, extraPickInfo: callConfig.pickInformation });
-        logging_1.trace(constants_1.LogVerbosity.DEBUG, 'channel', 'Pick result: ' +
+        const pickResult = this.currentPicker.pick({
+            metadata: callMetadata,
+            extraPickInfo: callConfig.pickInformation,
+        });
+        this.trace('Pick result: ' +
             picker_1.PickResultType[pickResult.pickResultType] +
@@ -226,8 +254,8 @@ ' subchannel: ' + ((_a = pickResult.subchannel) === null || _a === void 0 ? void 0 : _a.getAddress()) +
                     if (pickResult.subchannel.getConnectivityState() !==
-                        ConnectivityState.READY) {
+                        connectivity_state_1.ConnectivityState.READY) {
                         logging_1.log(constants_1.LogVerbosity.ERROR, 'Error: COMPLETE pick result subchannel ' +
                             pickResult.subchannel.getAddress() +
                             ' has state ' +
-                            ConnectivityState[pickResult.subchannel.getConnectivityState()]);
-                        this.pushPick(callStream, callMetadata, callConfig);
+                            connectivity_state_1.ConnectivityState[pickResult.subchannel.getConnectivityState()]);
+                        this.pushPick(callStream, callMetadata, callConfig, dynamicFilters);
                         break;
@@ -241,11 +269,12 @@ }
                         .then((finalMetadata) => {
-                        var _a, _b, _c;
+                        var _a, _b;
                         const subchannelState = pickResult.subchannel.getConnectivityState();
-                        if (subchannelState === ConnectivityState.READY) {
+                        if (subchannelState === connectivity_state_1.ConnectivityState.READY) {
                             try {
-                                pickResult.subchannel.startCallStream(finalMetadata, callStream, (_a = pickResult.extraFilterFactory) !== null && _a !== void 0 ? _a : undefined);
+                                const pickExtraFilters = pickResult.extraFilterFactories.map(factory => factory.createFilter(callStream));
+                                pickResult.subchannel.startCallStream(finalMetadata, callStream, [...dynamicFilters, ...pickExtraFilters]);
                                 /* If we reach this point, the call stream has started
                                  * successfully */
-                                (_b = callConfig.onCommitted) === null || _b === void 0 ? void 0 : _b.call(callConfig);
-                                (_c = pickResult.onCallStarted) === null || _c === void 0 ? void 0 : _c.call(pickResult);
+                                (_a = callConfig.onCommitted) === null || _a === void 0 ? void 0 : _a.call(callConfig);
+                                (_b = pickResult.onCallStarted) === null || _b === void 0 ? void 0 : _b.call(pickResult);
                             }
@@ -268,15 +297,15 @@ catch (error) {
                                      * tryPick */
-                                    logging_1.trace(constants_1.LogVerbosity.INFO, 'channel', 'Failed to start call on picked subchannel ' +
+                                    this.trace('Failed to start call on picked subchannel ' +
                                         pickResult.subchannel.getAddress() +
                                         ' with error ' +
                                         error.message +
-                                        '. Retrying pick');
-                                    this.tryPick(callStream, callMetadata, callConfig);
+                                        '. Retrying pick', constants_1.LogVerbosity.INFO);
+                                    this.tryPick(callStream, callMetadata, callConfig, dynamicFilters);
                                 }
                                 else {
-                                    logging_1.trace(constants_1.LogVerbosity.INFO, 'channel', 'Failed to start call on picked subchanel ' +
+                                    this.trace('Failed to start call on picked subchanel ' +
                                         pickResult.subchannel.getAddress() +
                                         ' with error ' +
                                         error.message +
-                                        '. Ending call');
+                                        '. Ending call', constants_1.LogVerbosity.INFO);
                                     callStream.cancelWithStatus(constants_1.Status.INTERNAL, `Failed to start HTTP/2 stream with error: ${error.message}`);
@@ -289,12 +318,12 @@ }
                              * block above */
-                            logging_1.trace(constants_1.LogVerbosity.INFO, 'channel', 'Picked subchannel ' +
+                            this.trace('Picked subchannel ' +
                                 pickResult.subchannel.getAddress() +
                                 ' has state ' +
-                                ConnectivityState[subchannelState] +
-                                ' after metadata filters. Retrying pick');
-                            this.tryPick(callStream, callMetadata, callConfig);
+                                connectivity_state_1.ConnectivityState[subchannelState] +
+                                ' after metadata filters. Retrying pick', constants_1.LogVerbosity.INFO);
+                            this.tryPick(callStream, callMetadata, callConfig, dynamicFilters);
                         }
                     }, (error) => {
                         // We assume the error code isn't 0 (Status.OK)
-                        callStream.cancelWithStatus((typeof error.code === 'number') ? error.code : constants_1.Status.UNKNOWN, `Getting metadata from plugin failed with error: ${error.message}`);
+                        callStream.cancelWithStatus(typeof error.code === 'number' ? error.code : constants_1.Status.UNKNOWN, `Getting metadata from plugin failed with error: ${error.message}`);
                     });
@@ -304,7 +333,7 @@ }
             case picker_1.PickResultType.QUEUE:
-                this.pushPick(callStream, callMetadata, callConfig);
+                this.pushPick(callStream, callMetadata, callConfig, dynamicFilters);
                 break;
             case picker_1.PickResultType.TRANSIENT_FAILURE:
                 if (callMetadata.getOptions().waitForReady) {
-                    this.pushPick(callStream, callMetadata, callConfig);
+                    this.pushPick(callStream, callMetadata, callConfig, dynamicFilters);
                 }
@@ -329,7 +358,9 @@ else {
     updateState(newState) {
-        logging_1.trace(constants_1.LogVerbosity.DEBUG, 'connectivity_state', uri_parser_1.uriToString(this.target) +
+        logging_1.trace(constants_1.LogVerbosity.DEBUG, 'connectivity_state', '(' + this.channelzRef.id + ') ' +
+            uri_parser_1.uriToString(this.target) +
             ' ' +
-            ConnectivityState[this.connectivityState] +
+            connectivity_state_1.ConnectivityState[this.connectivityState] +
             ' -> ' +
-            ConnectivityState[newState]);
+            connectivity_state_1.ConnectivityState[newState]);
+        this.channelzTrace.addTrace('CT_INFO', connectivity_state_1.ConnectivityState[this.connectivityState] + ' -> ' + connectivity_state_1.ConnectivityState[newState]);
         this.connectivityState = newState;
@@ -348,2 +379,7 @@ const watchersCopy = this.connectivityStateWatchers.slice();
     tryGetConfig(stream, metadata) {
+        if (stream.getStatus() !== null) {
+            /* If the stream has a status, it has already finished and we don't need
+             * to take any more actions on it. */
+            return;
+        }
         if (this.configSelector === null) {
@@ -357,3 +393,3 @@ /* This branch will only be taken at the beginning of the channel's life,
                 callStream: stream,
-                callMetadata: metadata
+                callMetadata: metadata,
             });
@@ -365,6 +401,36 @@ this.callRefTimerRef();
             if (callConfig.status === constants_1.Status.OK) {
-                this.tryPick(stream, metadata, callConfig);
+                if (callConfig.methodConfig.timeout) {
+                    const deadline = new Date();
+                    deadline.setSeconds(deadline.getSeconds() + callConfig.methodConfig.timeout.seconds);
+                    deadline.setMilliseconds(deadline.getMilliseconds() +
+                        callConfig.methodConfig.timeout.nanos / 1000000);
+                    stream.setConfigDeadline(deadline);
+                    // Refreshing the filters makes the deadline filter pick up the new deadline
+                    stream.filterStack.refresh();
+                }
+                if (callConfig.dynamicFilterFactories.length > 0) {
+                    /* These dynamicFilters are the mechanism for implementing gRFC A39:
+                     * https://github.com/grpc/proposal/blob/master/A39-xds-http-filters.md
+                     * We run them here instead of with the rest of the filters because
+                     * that spec says "the xDS HTTP filters will run in between name
+                     * resolution and load balancing".
+                     *
+                     * We use the filter stack here to simplify the multi-filter async
+                     * waterfall logic, but we pass along the underlying list of filters
+                     * to avoid having nested filter stacks when combining it with the
+                     * original filter stack. We do not pass along the original filter
+                     * factory list because these filters may need to persist data
+                     * between sending headers and other operations. */
+                    const dynamicFilterStackFactory = new filter_stack_1.FilterStackFactory(callConfig.dynamicFilterFactories);
+                    const dynamicFilterStack = dynamicFilterStackFactory.createFilter(stream);
+                    dynamicFilterStack.sendMetadata(Promise.resolve(metadata)).then(filteredMetadata => {
+                        this.tryPick(stream, filteredMetadata, callConfig, dynamicFilterStack.getFilters());
+                    });
+                }
+                else {
+                    this.tryPick(stream, metadata, callConfig, []);
+                }
             }
             else {
-                stream.cancelWithStatus(callConfig.status, "Failed to route call to method " + stream.getMethod());
+                stream.cancelWithStatus(callConfig.status, 'Failed to route call to method ' + stream.getMethod());
             }
@@ -378,4 +444,5 @@ }
         this.resolvingLoadBalancer.destroy();
-        this.updateState(ConnectivityState.SHUTDOWN);
+        this.updateState(connectivity_state_1.ConnectivityState.SHUTDOWN);
         clearInterval(this.callRefTimer);
+        channelz_1.unregisterChannelzRef(this.channelzRef);
         this.subchannelPool.unrefUnusedSubchannels();
@@ -394,3 +461,3 @@ }
     watchConnectivityState(currentState, deadline, callback) {
-        if (this.connectivityState === ConnectivityState.SHUTDOWN) {
+        if (this.connectivityState === connectivity_state_1.ConnectivityState.SHUTDOWN) {
             throw new Error('Channel has been shut down');
@@ -414,6 +481,9 @@ }
             callback,
-            timer
+            timer,
         };
         this.connectivityStateWatchers.push(watcherObject);
     }
+    getChannelzRef() {
+        return this.channelzRef;
+    }
     createCall(method, deadline, host, parentCall, propagateFlags) {
@@ -426,8 +496,7 @@ if (typeof method !== 'string') {
         }
-        if (this.connectivityState === ConnectivityState.SHUTDOWN) {
+        if (this.connectivityState === connectivity_state_1.ConnectivityState.SHUTDOWN) {
             throw new Error('Channel has been shut down');
         }
         const callNumber = getNewCallNumber();
-        logging_1.trace(constants_1.LogVerbosity.DEBUG, 'channel', uri_parser_1.uriToString(this.target) +
-            ' createCall [' +
+        this.trace('createCall [' +
             callNumber +
@@ -445,2 +514,11 @@ '] method="' +
         const stream = new call_stream_1.Http2CallStream(method, this, finalOptions, this.filterStackFactory, this.credentials._getCallCredentials(), callNumber);
+        this.callTracker.addCallStarted();
+        stream.addStatusWatcher(status => {
+            if (status.code === constants_1.Status.OK) {
+                this.callTracker.addCallSucceeded();
+            }
+            else {
+                this.callTracker.addCallFailed();
+            }
+        });
         return stream;
@@ -447,0 +525,0 @@ }

build/src/client.js

@@ -22,2 +22,3 @@ "use strict";
 const channel_1 = require("./channel");
+const connectivity_state_1 = require("./connectivity-state");
 const constants_1 = require("./constants");
@@ -85,3 +86,3 @@ const metadata_1 = require("./metadata");
             }
-            if (newState === channel_1.ConnectivityState.READY) {
+            if (newState === connectivity_state_1.ConnectivityState.READY) {
                 callback();
@@ -88,0 +89,0 @@ }

build/src/deadline-filter.d.ts

@@ -11,2 +11,5 @@ import { Call, StatusObject } from './call-stream';
     constructor(channel: Channel, callStream: Call);
+    private retreiveDeadline;
+    private runTimer;
+    refresh(): void;
     sendMetadata(metadata: Promise<Metadata>): Promise<Metadata>;
@@ -13,0 +16,0 @@ receiveTrailers(status: StatusObject): StatusObject;

build/src/deadline-filter.js

@@ -41,3 +41,2 @@ "use strict";
     constructor(channel, callStream) {
-        var _a, _b;
         super();
@@ -47,3 +46,8 @@ this.channel = channel;
         this.timer = null;
-        const callDeadline = callStream.getDeadline();
+        this.deadline = Infinity;
+        this.retreiveDeadline();
+        this.runTimer();
+    }
+    retreiveDeadline() {
+        const callDeadline = this.callStream.getDeadline();
         if (callDeadline instanceof Date) {
@@ -55,7 +59,13 @@ this.deadline = callDeadline.getTime();
         }
+    }
+    runTimer() {
+        var _a, _b;
+        if (this.timer) {
+            clearTimeout(this.timer);
+        }
         const now = new Date().getTime();
-        let timeout = this.deadline - now;
+        const timeout = this.deadline - now;
         if (timeout <= 0) {
             process.nextTick(() => {
-                callStream.cancelWithStatus(constants_1.Status.DEADLINE_EXCEEDED, 'Deadline exceeded');
+                this.callStream.cancelWithStatus(constants_1.Status.DEADLINE_EXCEEDED, 'Deadline exceeded');
             });
@@ -65,3 +75,3 @@ }
             this.timer = setTimeout(() => {
-                callStream.cancelWithStatus(constants_1.Status.DEADLINE_EXCEEDED, 'Deadline exceeded');
+                this.callStream.cancelWithStatus(constants_1.Status.DEADLINE_EXCEEDED, 'Deadline exceeded');
             }, timeout);
@@ -71,2 +81,6 @@ (_b = (_a = this.timer).unref) === null || _b === void 0 ? void 0 : _b.call(_a);
     }
+    refresh() {
+        this.retreiveDeadline();
+        this.runTimer();
+    }
     async sendMetadata(metadata) {
@@ -73,0 +87,0 @@ if (this.deadline === Infinity) {

build/src/experimental.d.ts

 export { trace } from './logging';
-export { Resolver, ResolverListener, registerResolver, ConfigSelector } from './resolver';
+export { Resolver, ResolverListener, registerResolver, ConfigSelector, } from './resolver';
 export { GrpcUri, uriToString } from './uri-parser';
-export { ServiceConfig } from './service-config';
+export { ServiceConfig, Duration } from './service-config';
 export { BackoffTimeout } from './backoff-timeout';
-export { LoadBalancer, LoadBalancingConfig, ChannelControlHelper, registerLoadBalancerType, getFirstUsableConfig, validateLoadBalancingConfig } from './load-balancer';
-export { SubchannelAddress, subchannelAddressToString } from './subchannel';
+export { LoadBalancer, LoadBalancingConfig, ChannelControlHelper, createChildChannelControlHelper, registerLoadBalancerType, getFirstUsableConfig, validateLoadBalancingConfig, } from './load-balancer';
+export { SubchannelAddress, subchannelAddressToString, } from './subchannel-address';
 export { ChildLoadBalancerHandler } from './load-balancer-child-handler';
-export { Picker, UnavailablePicker, QueuePicker, PickResult, PickArgs, PickResultType } from './picker';
+export { Picker, UnavailablePicker, QueuePicker, PickResult, PickArgs, PickResultType, } from './picker';
 export { Call as CallStream } from './call-stream';
 export { Filter, BaseFilter, FilterFactory } from './filter';
 export { FilterStackFactory } from './filter-stack';
+export { registerAdminService } from './admin';

build/src/experimental.js

@@ -12,7 +12,8 @@ "use strict";
 var load_balancer_1 = require("./load-balancer");
+Object.defineProperty(exports, "createChildChannelControlHelper", { enumerable: true, get: function () { return load_balancer_1.createChildChannelControlHelper; } });
 Object.defineProperty(exports, "registerLoadBalancerType", { enumerable: true, get: function () { return load_balancer_1.registerLoadBalancerType; } });
 Object.defineProperty(exports, "getFirstUsableConfig", { enumerable: true, get: function () { return load_balancer_1.getFirstUsableConfig; } });
 Object.defineProperty(exports, "validateLoadBalancingConfig", { enumerable: true, get: function () { return load_balancer_1.validateLoadBalancingConfig; } });
-var subchannel_1 = require("./subchannel");
-Object.defineProperty(exports, "subchannelAddressToString", { enumerable: true, get: function () { return subchannel_1.subchannelAddressToString; } });
+var subchannel_address_1 = require("./subchannel-address");
+Object.defineProperty(exports, "subchannelAddressToString", { enumerable: true, get: function () { return subchannel_address_1.subchannelAddressToString; } });
 var load_balancer_child_handler_1 = require("./load-balancer-child-handler");
@@ -28,2 +29,4 @@ Object.defineProperty(exports, "ChildLoadBalancerHandler", { enumerable: true, get: function () { return load_balancer_child_handler_1.ChildLoadBalancerHandler; } });
 Object.defineProperty(exports, "FilterStackFactory", { enumerable: true, get: function () { return filter_stack_1.FilterStackFactory; } });
+var admin_1 = require("./admin");
+Object.defineProperty(exports, "registerAdminService", { enumerable: true, get: function () { return admin_1.registerAdminService; } });
 //# sourceMappingURL=experimental.js.map

build/src/filter-stack.d.ts

@@ -13,2 +13,5 @@ /// <reference types="node" />
     receiveTrailers(status: StatusObject): StatusObject;
+    refresh(): void;
+    push(filters: Filter[]): void;
+    getFilters(): Filter[];
 }
@@ -18,3 +21,4 @@ export declare class FilterStackFactory implements FilterFactory<FilterStack> {
     constructor(factories: Array<FilterFactory<Filter>>);
+    push(filterFactories: FilterFactory<Filter>[]): void;
     createFilter(callStream: Call): FilterStack;
 }

build/src/filter-stack.js

@@ -59,2 +59,13 @@ "use strict";
     }
+    refresh() {
+        for (const filter of this.filters) {
+            filter.refresh();
+        }
+    }
+    push(filters) {
+        this.filters.unshift(...filters);
+    }
+    getFilters() {
+        return this.filters;
+    }
 }
@@ -66,2 +77,5 @@ exports.FilterStack = FilterStack;
     }
+    push(filterFactories) {
+        this.factories.unshift(...filterFactories);
+    }
     createFilter(callStream) {
@@ -68,0 +82,0 @@ return new FilterStack(this.factories.map((factory) => factory.createFilter(callStream)));

build/src/filter.d.ts

@@ -14,2 +14,3 @@ /// <reference types="node" />
     receiveTrailers(status: StatusObject): StatusObject;
+    refresh(): void;
 }
@@ -22,2 +23,3 @@ export declare abstract class BaseFilter implements Filter {
     receiveTrailers(status: StatusObject): StatusObject;
+    refresh(): void;
 }
@@ -24,0 +26,0 @@ export interface FilterFactory<T extends Filter> {

build/src/filter.js

@@ -36,4 +36,5 @@ "use strict";
     }
+    refresh() { }
 }
 exports.BaseFilter = BaseFilter;
 //# sourceMappingURL=filter.js.map

build/src/http_proxy.d.ts

 /// <reference types="node" />
 import { Socket } from 'net';
 import * as tls from 'tls';
-import { SubchannelAddress } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 import { ChannelOptions } from './channel-options';
@@ -6,0 +6,0 @@ import { GrpcUri } from './uri-parser';

build/src/http_proxy.js

@@ -26,3 +26,3 @@ "use strict";
 const logging = require("./logging");
-const subchannel_1 = require("./subchannel");
+const subchannel_address_1 = require("./subchannel-address");
 const uri_parser_1 = require("./uri-parser");
@@ -87,3 +87,3 @@ const url_1 = require("url");
     const result = {
-        address: `${hostname}:${port}`
+        address: `${hostname}:${port}`,
     };
@@ -164,4 +164,7 @@ if (userCred) {
     };
+    const headers = {
+        Host: parsedTarget.path,
+    };
     // Connect to the subchannel address as a proxy
-    if (subchannel_1.isTcpSubchannelAddress(address)) {
+    if (subchannel_address_1.isTcpSubchannelAddress(address)) {
         options.host = address.host;
@@ -174,8 +177,8 @@ options.port = address.port;
     if ('grpc.http_connect_creds' in channelOptions) {
-        options.headers = {
-            'Proxy-Authorization': 'Basic ' +
-                Buffer.from(channelOptions['grpc.http_connect_creds']).toString('base64'),
-        };
+        headers['Proxy-Authorization'] =
+            'Basic ' +
+                Buffer.from(channelOptions['grpc.http_connect_creds']).toString('base64');
     }
-    const proxyAddressString = subchannel_1.subchannelAddressToString(address);
+    options.headers = headers;
+    const proxyAddressString = subchannel_address_1.subchannelAddressToString(address);
     trace('Using proxy ' + proxyAddressString + ' to connect to ' + options.path);
@@ -182,0 +185,0 @@ return new Promise((resolve, reject) => {

build/src/index.d.ts

@@ -5,3 +5,4 @@ /// <reference types="node" />
 import { Deadline, StatusObject } from './call-stream';
-import { Channel, ConnectivityState, ChannelImplementation } from './channel';
+import { Channel, ChannelImplementation } from './channel';
+import { ConnectivityState } from './connectivity-state';
 import { ChannelCredentials } from './channel-credentials';
@@ -15,3 +16,3 @@ import { CallOptions, Client, ClientOptions, CallInvocationTransformer, CallProperties, UnaryCallback } from './client';
 import { StatusBuilder } from './status-builder';
-import { handleBidiStreamingCall, handleServerStreamingCall, handleClientStreamingCall, handleUnaryCall, sendUnaryData, ServerUnaryCall, ServerReadableStream, ServerWritableStream, ServerDuplexStream } from './server-call';
+import { handleBidiStreamingCall, handleServerStreamingCall, handleClientStreamingCall, handleUnaryCall, sendUnaryData, ServerUnaryCall, ServerReadableStream, ServerWritableStream, ServerDuplexStream, ServerErrorResponse } from './server-call';
 export { OAuth2Client };
@@ -54,5 +55,5 @@ /**** Client Credentials ****/
 export declare const waitForClientReady: (client: Client, deadline: Date | number, callback: (error?: Error | undefined) => void) => void;
-export { sendUnaryData, ChannelCredentials, CallCredentials, Deadline, Serialize as serialize, Deserialize as deserialize, ClientUnaryCall, ClientReadableStream, ClientWritableStream, ClientDuplexStream, CallOptions, MethodDefinition, StatusObject, ServiceError, ServerUnaryCall, ServerReadableStream, ServerWritableStream, ServerDuplexStream, ServiceDefinition, UntypedHandleCall, UntypedServiceImplementation, };
+export { sendUnaryData, ChannelCredentials, CallCredentials, Deadline, Serialize as serialize, Deserialize as deserialize, ClientUnaryCall, ClientReadableStream, ClientWritableStream, ClientDuplexStream, CallOptions, MethodDefinition, StatusObject, ServiceError, ServerUnaryCall, ServerReadableStream, ServerWritableStream, ServerDuplexStream, ServerErrorResponse, ServiceDefinition, UntypedHandleCall, UntypedServiceImplementation, };
 /**** Server ****/
-export { handleBidiStreamingCall, handleServerStreamingCall, handleUnaryCall, handleClientStreamingCall };
+export { handleBidiStreamingCall, handleServerStreamingCall, handleUnaryCall, handleClientStreamingCall, };
 export declare type Call = ClientUnaryCall | ClientReadableStream<any> | ClientWritableStream<any> | ClientDuplexStream<any, any>;
@@ -73,3 +74,5 @@ /**** Unimplemented function stubs ****/
 export { ChannelOptions } from './channel-options';
+export { getChannelzServiceDefinition, getChannelzHandlers } from './channelz';
+export { addAdminServicesToServer } from './admin';
 import * as experimental from './experimental';
 export { experimental };

build/src/index.js

@@ -23,4 +23,5 @@ "use strict";
 const channel_1 = require("./channel");
-Object.defineProperty(exports, "connectivityState", { enumerable: true, get: function () { return channel_1.ConnectivityState; } });
 Object.defineProperty(exports, "Channel", { enumerable: true, get: function () { return channel_1.ChannelImplementation; } });
+const connectivity_state_1 = require("./connectivity-state");
+Object.defineProperty(exports, "connectivityState", { enumerable: true, get: function () { return connectivity_state_1.ConnectivityState; } });
 const channel_credentials_1 = require("./channel-credentials");
@@ -107,12 +108,25 @@ Object.defineProperty(exports, "ChannelCredentials", { enumerable: true, get: function () { return channel_credentials_1.ChannelCredentials; } });
 Object.defineProperty(exports, "InterceptorConfigurationError", { enumerable: true, get: function () { return client_interceptors_1.InterceptorConfigurationError; } });
+var channelz_1 = require("./channelz");
+Object.defineProperty(exports, "getChannelzServiceDefinition", { enumerable: true, get: function () { return channelz_1.getChannelzServiceDefinition; } });
+Object.defineProperty(exports, "getChannelzHandlers", { enumerable: true, get: function () { return channelz_1.getChannelzHandlers; } });
+var admin_1 = require("./admin");
+Object.defineProperty(exports, "addAdminServicesToServer", { enumerable: true, get: function () { return admin_1.addAdminServicesToServer; } });
 const experimental = require("./experimental");
 exports.experimental = experimental;
-const resolver = require("./resolver");
-const load_balancer = require("./load-balancer");
+const resolver_dns = require("./resolver-dns");
+const resolver_uds = require("./resolver-uds");
+const resolver_ip = require("./resolver-ip");
+const load_balancer_pick_first = require("./load-balancer-pick-first");
+const load_balancer_round_robin = require("./load-balancer-round-robin");
+const channelz = require("./channelz");
 const clientVersion = require('../../package.json').version;
 (() => {
     logging.trace(constants_1.LogVerbosity.DEBUG, 'index', 'Loading @grpc/grpc-js version ' + clientVersion);
-    resolver.registerAll();
-    load_balancer.registerAll();
+    resolver_dns.setup();
+    resolver_uds.setup();
+    resolver_ip.setup();
+    load_balancer_pick_first.setup();
+    load_balancer_round_robin.setup();
+    channelz.setup();
 })();
 //# sourceMappingURL=index.js.map

build/src/load-balancer-child-handler.d.ts

 import { LoadBalancer, ChannelControlHelper, LoadBalancingConfig } from './load-balancer';
-import { SubchannelAddress } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 export declare class ChildLoadBalancerHandler implements LoadBalancer {
@@ -4,0 +4,0 @@ private readonly channelControlHelper;

build/src/load-balancer-child-handler.js

@@ -21,3 +21,3 @@ "use strict";
 const load_balancer_1 = require("./load-balancer");
-const channel_1 = require("./channel");
+const connectivity_state_1 = require("./connectivity-state");
 const TYPE_NAME = 'child_load_balancer_helper';
@@ -40,3 +40,3 @@ class ChildLoadBalancerHandler {
                 if (this.calledByPendingChild()) {
-                    if (connectivityState !== channel_1.ConnectivityState.READY) {
+                    if (connectivityState !== connectivity_state_1.ConnectivityState.READY) {
                         return;
@@ -63,2 +63,8 @@ }
             }
+            addChannelzChild(child) {
+                this.parent.channelControlHelper.addChannelzChild(child);
+            }
+            removeChannelzChild(child) {
+                this.parent.channelControlHelper.removeChannelzChild(child);
+            }
             calledByPendingChild() {
@@ -65,0 +71,0 @@ return this.child === this.parent.pendingChild;

build/src/load-balancer-pick-first.d.ts

 import { LoadBalancer, ChannelControlHelper, LoadBalancingConfig } from './load-balancer';
-import { SubchannelAddress } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 export declare class PickFirstLoadBalancingConfig implements LoadBalancingConfig {
@@ -4,0 +4,0 @@ getLoadBalancerName(): string;

build/src/load-balancer-pick-first.js

@@ -21,5 +21,5 @@ "use strict";
 const load_balancer_1 = require("./load-balancer");
-const channel_1 = require("./channel");
+const connectivity_state_1 = require("./connectivity-state");
 const picker_1 = require("./picker");
-const subchannel_1 = require("./subchannel");
+const subchannel_address_1 = require("./subchannel-address");
 const logging = require("./logging");
@@ -44,5 +44,6 @@ const constants_1 = require("./constants");
         return {
-            [TYPE_NAME]: {}
+            [TYPE_NAME]: {},
         };
     }
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
     static createFromJson(obj) {
@@ -66,3 +67,3 @@ return new PickFirstLoadBalancingConfig();
             status: null,
-            extraFilterFactory: null,
+            extraFilterFactories: [],
             onCallStarted: null,
@@ -94,3 +95,3 @@ };
          */
-        this.currentState = channel_1.ConnectivityState.IDLE;
+        this.currentState = connectivity_state_1.ConnectivityState.IDLE;
         /**
@@ -109,7 +110,7 @@ * The index within the `subchannels` array of the subchannel with the most
         this.subchannelStateCounts = {
-            [channel_1.ConnectivityState.CONNECTING]: 0,
-            [channel_1.ConnectivityState.IDLE]: 0,
-            [channel_1.ConnectivityState.READY]: 0,
-            [channel_1.ConnectivityState.SHUTDOWN]: 0,
-            [channel_1.ConnectivityState.TRANSIENT_FAILURE]: 0,
+            [connectivity_state_1.ConnectivityState.CONNECTING]: 0,
+            [connectivity_state_1.ConnectivityState.IDLE]: 0,
+            [connectivity_state_1.ConnectivityState.READY]: 0,
+            [connectivity_state_1.ConnectivityState.SHUTDOWN]: 0,
+            [connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE]: 0,
         };
@@ -124,6 +125,6 @@ this.subchannelStateListener = (subchannel, previousState, newState) => {
             if (subchannel === this.subchannels[this.currentSubchannelIndex] &&
-                newState === channel_1.ConnectivityState.TRANSIENT_FAILURE) {
+                newState === connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE) {
                 this.startNextSubchannelConnecting();
             }
-            if (newState === channel_1.ConnectivityState.READY) {
+            if (newState === connectivity_state_1.ConnectivityState.READY) {
                 this.pickSubchannel(subchannel);
@@ -134,3 +135,3 @@ return;
                 if (this.triedAllSubchannels &&
-                    this.subchannelStateCounts[channel_1.ConnectivityState.IDLE] ===
+                    this.subchannelStateCounts[connectivity_state_1.ConnectivityState.IDLE] ===
                         this.subchannels.length) {
@@ -141,3 +142,3 @@ /* If all of the subchannels are IDLE we should go back to a
                     this.resetSubchannelList();
-                    this.updateState(channel_1.ConnectivityState.IDLE, new picker_1.QueuePicker(this));
+                    this.updateState(connectivity_state_1.ConnectivityState.IDLE, new picker_1.QueuePicker(this));
                     return;
@@ -148,14 +149,14 @@ }
                         let newLBState;
-                        if (this.subchannelStateCounts[channel_1.ConnectivityState.CONNECTING] > 0) {
-                            newLBState = channel_1.ConnectivityState.CONNECTING;
+                        if (this.subchannelStateCounts[connectivity_state_1.ConnectivityState.CONNECTING] > 0) {
+                            newLBState = connectivity_state_1.ConnectivityState.CONNECTING;
                         }
-                        else if (this.subchannelStateCounts[channel_1.ConnectivityState.TRANSIENT_FAILURE] >
+                        else if (this.subchannelStateCounts[connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE] >
                             0) {
-                            newLBState = channel_1.ConnectivityState.TRANSIENT_FAILURE;
+                            newLBState = connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE;
                         }
                         else {
-                            newLBState = channel_1.ConnectivityState.IDLE;
+                            newLBState = connectivity_state_1.ConnectivityState.IDLE;
                         }
                         if (newLBState !== this.currentState) {
-                            if (newLBState === channel_1.ConnectivityState.TRANSIENT_FAILURE) {
+                            if (newLBState === connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE) {
                                 this.updateState(newLBState, new picker_1.UnavailablePicker());
@@ -169,3 +170,3 @@ }
                     else {
-                        this.updateState(channel_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
+                        this.updateState(connectivity_state_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
                     }
@@ -176,20 +177,21 @@ }
         this.pickedSubchannelStateListener = (subchannel, previousState, newState) => {
-            if (newState !== channel_1.ConnectivityState.READY) {
+            if (newState !== connectivity_state_1.ConnectivityState.READY) {
                 this.currentPick = null;
                 subchannel.unref();
                 subchannel.removeConnectivityStateListener(this.pickedSubchannelStateListener);
+                this.channelControlHelper.removeChannelzChild(subchannel.getChannelzRef());
                 if (this.subchannels.length > 0) {
                     if (this.triedAllSubchannels) {
                         let newLBState;
-                        if (this.subchannelStateCounts[channel_1.ConnectivityState.CONNECTING] > 0) {
-                            newLBState = channel_1.ConnectivityState.CONNECTING;
+                        if (this.subchannelStateCounts[connectivity_state_1.ConnectivityState.CONNECTING] > 0) {
+                            newLBState = connectivity_state_1.ConnectivityState.CONNECTING;
                         }
-                        else if (this.subchannelStateCounts[channel_1.ConnectivityState.TRANSIENT_FAILURE] >
+                        else if (this.subchannelStateCounts[connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE] >
                             0) {
-                            newLBState = channel_1.ConnectivityState.TRANSIENT_FAILURE;
+                            newLBState = connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE;
                         }
                         else {
-                            newLBState = channel_1.ConnectivityState.IDLE;
+                            newLBState = connectivity_state_1.ConnectivityState.IDLE;
                         }
-                        if (newLBState === channel_1.ConnectivityState.TRANSIENT_FAILURE) {
+                        if (newLBState === connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE) {
                             this.updateState(newLBState, new picker_1.UnavailablePicker());
@@ -202,3 +204,3 @@ }
                     else {
-                        this.updateState(channel_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
+                        this.updateState(connectivity_state_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
                     }
@@ -211,3 +213,3 @@ }
                      */
-                    this.updateState(channel_1.ConnectivityState.IDLE, new picker_1.QueuePicker(this));
+                    this.updateState(connectivity_state_1.ConnectivityState.IDLE, new picker_1.QueuePicker(this));
                 }
@@ -226,4 +228,4 @@ }
                 const subchannelState = subchannel.getConnectivityState();
-                if (subchannelState === channel_1.ConnectivityState.IDLE ||
-                    subchannelState === channel_1.ConnectivityState.CONNECTING) {
+                if (subchannelState === connectivity_state_1.ConnectivityState.IDLE ||
+                    subchannelState === connectivity_state_1.ConnectivityState.CONNECTING) {
                     this.startConnecting(index);
@@ -244,3 +246,3 @@ return;
         if (this.subchannels[subchannelIndex].getConnectivityState() ===
-            channel_1.ConnectivityState.IDLE) {
+            connectivity_state_1.ConnectivityState.IDLE) {
             trace('Start connecting to subchannel with address ' +
@@ -263,5 +265,6 @@ this.subchannels[subchannelIndex].getAddress());
         this.currentPick = subchannel;
-        this.updateState(channel_1.ConnectivityState.READY, new PickFirstPicker(subchannel));
+        this.updateState(connectivity_state_1.ConnectivityState.READY, new PickFirstPicker(subchannel));
         subchannel.addConnectivityStateListener(this.pickedSubchannelStateListener);
         subchannel.ref();
+        this.channelControlHelper.addChannelzChild(subchannel.getChannelzRef());
         this.resetSubchannelList();
@@ -271,5 +274,5 @@ clearTimeout(this.connectionDelayTimeout);
     updateState(newState, picker) {
-        trace(channel_1.ConnectivityState[this.currentState] +
+        trace(connectivity_state_1.ConnectivityState[this.currentState] +
             ' -> ' +
-            channel_1.ConnectivityState[newState]);
+            connectivity_state_1.ConnectivityState[newState]);
         this.currentState = newState;
@@ -282,10 +285,11 @@ this.channelControlHelper.updateState(newState, picker);
             subchannel.unref();
+            this.channelControlHelper.removeChannelzChild(subchannel.getChannelzRef());
         }
         this.currentSubchannelIndex = 0;
         this.subchannelStateCounts = {
-            [channel_1.ConnectivityState.CONNECTING]: 0,
-            [channel_1.ConnectivityState.IDLE]: 0,
-            [channel_1.ConnectivityState.READY]: 0,
-            [channel_1.ConnectivityState.SHUTDOWN]: 0,
-            [channel_1.ConnectivityState.TRANSIENT_FAILURE]: 0,
+            [connectivity_state_1.ConnectivityState.CONNECTING]: 0,
+            [connectivity_state_1.ConnectivityState.IDLE]: 0,
+            [connectivity_state_1.ConnectivityState.READY]: 0,
+            [connectivity_state_1.ConnectivityState.SHUTDOWN]: 0,
+            [connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE]: 0,
         };
@@ -302,6 +306,7 @@ this.subchannels = [];
         trace('Connect to address list ' +
-            this.latestAddressList.map((address) => subchannel_1.subchannelAddressToString(address)));
+            this.latestAddressList.map((address) => subchannel_address_1.subchannelAddressToString(address)));
         this.subchannels = this.latestAddressList.map((address) => this.channelControlHelper.createSubchannel(address, {}));
         for (const subchannel of this.subchannels) {
             subchannel.ref();
+            this.channelControlHelper.addChannelzChild(subchannel.getChannelzRef());
         }
@@ -311,3 +316,3 @@ for (const subchannel of this.subchannels) {
             this.subchannelStateCounts[subchannel.getConnectivityState()] += 1;
-            if (subchannel.getConnectivityState() === channel_1.ConnectivityState.READY) {
+            if (subchannel.getConnectivityState() === connectivity_state_1.ConnectivityState.READY) {
                 this.pickSubchannel(subchannel);
@@ -320,7 +325,7 @@ this.resetSubchannelList();
             const subchannelState = subchannel.getConnectivityState();
-            if (subchannelState === channel_1.ConnectivityState.IDLE ||
-                subchannelState === channel_1.ConnectivityState.CONNECTING) {
+            if (subchannelState === connectivity_state_1.ConnectivityState.IDLE ||
+                subchannelState === connectivity_state_1.ConnectivityState.CONNECTING) {
                 this.startConnecting(index);
                 if (this.currentPick === null) {
-                    this.updateState(channel_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
+                    this.updateState(connectivity_state_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
                 }
@@ -332,3 +337,3 @@ return;
         if (this.currentPick === null) {
-            this.updateState(channel_1.ConnectivityState.TRANSIENT_FAILURE, new picker_1.UnavailablePicker());
+            this.updateState(connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE, new picker_1.UnavailablePicker());
         }
@@ -351,3 +356,3 @@ }
         }
-        if (this.currentState === channel_1.ConnectivityState.IDLE) {
+        if (this.currentState === connectivity_state_1.ConnectivityState.IDLE) {
             if (this.latestAddressList.length > 0) {
@@ -357,3 +362,3 @@ this.connectToAddressList();
         }
-        if (this.currentState === channel_1.ConnectivityState.IDLE ||
+        if (this.currentState === connectivity_state_1.ConnectivityState.IDLE ||
             this.triedAllSubchannels) {
@@ -372,2 +377,3 @@ this.channelControlHelper.requestReresolution();
             this.currentPick.removeConnectivityStateListener(this.pickedSubchannelStateListener);
+            this.channelControlHelper.removeChannelzChild(this.currentPick.getChannelzRef());
         }
@@ -382,4 +388,5 @@ }
     load_balancer_1.registerLoadBalancerType(TYPE_NAME, PickFirstLoadBalancer, PickFirstLoadBalancingConfig);
+    load_balancer_1.registerDefaultLoadBalancerType(TYPE_NAME);
 }
 exports.setup = setup;
 //# sourceMappingURL=load-balancer-pick-first.js.map

build/src/load-balancer-round-robin.d.ts

 import { LoadBalancer, ChannelControlHelper, LoadBalancingConfig } from './load-balancer';
-import { SubchannelAddress } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 export declare class RoundRobinLoadBalancer implements LoadBalancer {
@@ -4,0 +4,0 @@ private readonly channelControlHelper;

build/src/load-balancer-round-robin.js

@@ -21,5 +21,5 @@ "use strict";
 const load_balancer_1 = require("./load-balancer");
-const channel_1 = require("./channel");
+const connectivity_state_1 = require("./connectivity-state");
 const picker_1 = require("./picker");
-const subchannel_1 = require("./subchannel");
+const subchannel_address_1 = require("./subchannel-address");
 const logging = require("./logging");
@@ -39,5 +39,6 @@ const constants_1 = require("./constants");
         return {
-            [TYPE_NAME]: {}
+            [TYPE_NAME]: {},
         };
     }
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
     static createFromJson(obj) {
@@ -59,3 +60,3 @@ return new RoundRobinLoadBalancingConfig();
             status: null,
-            extraFilterFactory: null,
+            extraFilterFactories: [],
             onCallStarted: null,
@@ -77,10 +78,10 @@ };
         this.subchannels = [];
-        this.currentState = channel_1.ConnectivityState.IDLE;
+        this.currentState = connectivity_state_1.ConnectivityState.IDLE;
         this.currentReadyPicker = null;
         this.subchannelStateCounts = {
-            [channel_1.ConnectivityState.CONNECTING]: 0,
-            [channel_1.ConnectivityState.IDLE]: 0,
-            [channel_1.ConnectivityState.READY]: 0,
-            [channel_1.ConnectivityState.SHUTDOWN]: 0,
-            [channel_1.ConnectivityState.TRANSIENT_FAILURE]: 0,
+            [connectivity_state_1.ConnectivityState.CONNECTING]: 0,
+            [connectivity_state_1.ConnectivityState.IDLE]: 0,
+            [connectivity_state_1.ConnectivityState.READY]: 0,
+            [connectivity_state_1.ConnectivityState.SHUTDOWN]: 0,
+            [connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE]: 0,
         };
@@ -91,4 +92,4 @@ this.subchannelStateListener = (subchannel, previousState, newState) => {
             this.calculateAndUpdateState();
-            if (newState === channel_1.ConnectivityState.TRANSIENT_FAILURE ||
-                newState === channel_1.ConnectivityState.IDLE) {
+            if (newState === connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE ||
+                newState === connectivity_state_1.ConnectivityState.IDLE) {
                 this.channelControlHelper.requestReresolution();
@@ -100,4 +101,4 @@ subchannel.startConnecting();
     calculateAndUpdateState() {
-        if (this.subchannelStateCounts[channel_1.ConnectivityState.READY] > 0) {
-            const readySubchannels = this.subchannels.filter((subchannel) => subchannel.getConnectivityState() === channel_1.ConnectivityState.READY);
+        if (this.subchannelStateCounts[connectivity_state_1.ConnectivityState.READY] > 0) {
+            const readySubchannels = this.subchannels.filter((subchannel) => subchannel.getConnectivityState() === connectivity_state_1.ConnectivityState.READY);
             let index = 0;
@@ -110,19 +111,19 @@ if (this.currentReadyPicker !== null) {
             }
-            this.updateState(channel_1.ConnectivityState.READY, new RoundRobinPicker(readySubchannels, index));
+            this.updateState(connectivity_state_1.ConnectivityState.READY, new RoundRobinPicker(readySubchannels, index));
         }
-        else if (this.subchannelStateCounts[channel_1.ConnectivityState.CONNECTING] > 0) {
-            this.updateState(channel_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
+        else if (this.subchannelStateCounts[connectivity_state_1.ConnectivityState.CONNECTING] > 0) {
+            this.updateState(connectivity_state_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
         }
-        else if (this.subchannelStateCounts[channel_1.ConnectivityState.TRANSIENT_FAILURE] > 0) {
-            this.updateState(channel_1.ConnectivityState.TRANSIENT_FAILURE, new picker_1.UnavailablePicker());
+        else if (this.subchannelStateCounts[connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE] > 0) {
+            this.updateState(connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE, new picker_1.UnavailablePicker());
         }
         else {
-            this.updateState(channel_1.ConnectivityState.IDLE, new picker_1.QueuePicker(this));
+            this.updateState(connectivity_state_1.ConnectivityState.IDLE, new picker_1.QueuePicker(this));
         }
     }
     updateState(newState, picker) {
-        trace(channel_1.ConnectivityState[this.currentState] +
+        trace(connectivity_state_1.ConnectivityState[this.currentState] +
             ' -> ' +
-            channel_1.ConnectivityState[newState]);
-        if (newState === channel_1.ConnectivityState.READY) {
+            connectivity_state_1.ConnectivityState[newState]);
+        if (newState === connectivity_state_1.ConnectivityState.READY) {
             this.currentReadyPicker = picker;
@@ -140,9 +141,10 @@ }
             subchannel.unref();
+            this.channelControlHelper.removeChannelzChild(subchannel.getChannelzRef());
         }
         this.subchannelStateCounts = {
-            [channel_1.ConnectivityState.CONNECTING]: 0,
-            [channel_1.ConnectivityState.IDLE]: 0,
-            [channel_1.ConnectivityState.READY]: 0,
-            [channel_1.ConnectivityState.SHUTDOWN]: 0,
-            [channel_1.ConnectivityState.TRANSIENT_FAILURE]: 0,
+            [connectivity_state_1.ConnectivityState.CONNECTING]: 0,
+            [connectivity_state_1.ConnectivityState.IDLE]: 0,
+            [connectivity_state_1.ConnectivityState.READY]: 0,
+            [connectivity_state_1.ConnectivityState.SHUTDOWN]: 0,
+            [connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE]: 0,
         };
@@ -154,3 +156,3 @@ this.subchannels = [];
         trace('Connect to address list ' +
-            addressList.map((address) => subchannel_1.subchannelAddressToString(address)));
+            addressList.map((address) => subchannel_address_1.subchannelAddressToString(address)));
         this.subchannels = addressList.map((address) => this.channelControlHelper.createSubchannel(address, {}));
@@ -160,6 +162,7 @@ for (const subchannel of this.subchannels) {
             subchannel.addConnectivityStateListener(this.subchannelStateListener);
+            this.channelControlHelper.addChannelzChild(subchannel.getChannelzRef());
             const subchannelState = subchannel.getConnectivityState();
             this.subchannelStateCounts[subchannelState] += 1;
-            if (subchannelState === channel_1.ConnectivityState.IDLE ||
-                subchannelState === channel_1.ConnectivityState.TRANSIENT_FAILURE) {
+            if (subchannelState === connectivity_state_1.ConnectivityState.IDLE ||
+                subchannelState === connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE) {
                 subchannel.startConnecting();
@@ -166,0 +169,0 @@ }

build/src/load-balancer.d.ts

 import { ChannelOptions } from './channel-options';
-import { Subchannel, SubchannelAddress } from './subchannel';
-import { ConnectivityState } from './channel';
+import { Subchannel } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
+import { ConnectivityState } from './connectivity-state';
 import { Picker } from './picker';
+import { ChannelRef, SubchannelRef } from './channelz';
 /**
@@ -28,4 +30,15 @@ * A collection of functions associated with a channel that a load balancer
     requestReresolution(): void;
+    addChannelzChild(child: ChannelRef | SubchannelRef): void;
+    removeChannelzChild(child: ChannelRef | SubchannelRef): void;
 }
 /**
+ * Create a child ChannelControlHelper that overrides some methods of the
+ * parent while letting others pass through to the parent unmodified. This
+ * allows other code to create these children without needing to know about
+ * all of the methods to be passed through.
+ * @param parent
+ * @param overrides
+ */
+export declare function createChildChannelControlHelper(parent: ChannelControlHelper, overrides: Partial<ChannelControlHelper>): ChannelControlHelper;
+/**
  * Tracks one or more connected subchannels and determines which subchannel
@@ -81,6 +94,6 @@ * each request should use.
 export declare function registerLoadBalancerType(typeName: string, loadBalancerType: LoadBalancerConstructor, loadBalancingConfigType: LoadBalancingConfigConstructor): void;
+export declare function registerDefaultLoadBalancerType(typeName: string): void;
 export declare function createLoadBalancer(config: LoadBalancingConfig, channelControlHelper: ChannelControlHelper): LoadBalancer | null;
 export declare function isLoadBalancerNameRegistered(typeName: string): boolean;
-export declare function getFirstUsableConfig(configs: LoadBalancingConfig[], defaultPickFirst?: true): LoadBalancingConfig;
+export declare function getFirstUsableConfig(configs: LoadBalancingConfig[], fallbackTodefault?: true): LoadBalancingConfig;
 export declare function validateLoadBalancingConfig(obj: any): LoadBalancingConfig;
-export declare function registerAll(): void;

build/src/load-balancer.js

@@ -19,13 +19,35 @@ "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-exports.registerAll = exports.validateLoadBalancingConfig = exports.getFirstUsableConfig = exports.isLoadBalancerNameRegistered = exports.createLoadBalancer = exports.registerLoadBalancerType = void 0;
-const load_balancer_pick_first = require("./load-balancer-pick-first");
-const load_balancer_round_robin = require("./load-balancer-round-robin");
+exports.validateLoadBalancingConfig = exports.getFirstUsableConfig = exports.isLoadBalancerNameRegistered = exports.createLoadBalancer = exports.registerDefaultLoadBalancerType = exports.registerLoadBalancerType = exports.createChildChannelControlHelper = void 0;
+/**
+ * Create a child ChannelControlHelper that overrides some methods of the
+ * parent while letting others pass through to the parent unmodified. This
+ * allows other code to create these children without needing to know about
+ * all of the methods to be passed through.
+ * @param parent
+ * @param overrides
+ */
+function createChildChannelControlHelper(parent, overrides) {
+    var _a, _b, _c, _d, _e, _f, _g, _h, _j, _k;
+    return {
+        createSubchannel: (_b = (_a = overrides.createSubchannel) === null || _a === void 0 ? void 0 : _a.bind(overrides)) !== null && _b !== void 0 ? _b : parent.createSubchannel.bind(parent),
+        updateState: (_d = (_c = overrides.updateState) === null || _c === void 0 ? void 0 : _c.bind(overrides)) !== null && _d !== void 0 ? _d : parent.updateState.bind(parent),
+        requestReresolution: (_f = (_e = overrides.requestReresolution) === null || _e === void 0 ? void 0 : _e.bind(overrides)) !== null && _f !== void 0 ? _f : parent.requestReresolution.bind(parent),
+        addChannelzChild: (_h = (_g = overrides.addChannelzChild) === null || _g === void 0 ? void 0 : _g.bind(overrides)) !== null && _h !== void 0 ? _h : parent.addChannelzChild.bind(parent),
+        removeChannelzChild: (_k = (_j = overrides.removeChannelzChild) === null || _j === void 0 ? void 0 : _j.bind(overrides)) !== null && _k !== void 0 ? _k : parent.removeChannelzChild.bind(parent)
+    };
+}
+exports.createChildChannelControlHelper = createChildChannelControlHelper;
 const registeredLoadBalancerTypes = {};
+let defaultLoadBalancerType = null;
 function registerLoadBalancerType(typeName, loadBalancerType, loadBalancingConfigType) {
     registeredLoadBalancerTypes[typeName] = {
         LoadBalancer: loadBalancerType,
-        LoadBalancingConfig: loadBalancingConfigType
+        LoadBalancingConfig: loadBalancingConfigType,
     };
 }
 exports.registerLoadBalancerType = registerLoadBalancerType;
+function registerDefaultLoadBalancerType(typeName) {
+    defaultLoadBalancerType = typeName;
+}
+exports.registerDefaultLoadBalancerType = registerDefaultLoadBalancerType;
 function createLoadBalancer(config, channelControlHelper) {
@@ -45,3 +67,3 @@ const typeName = config.getLoadBalancerName();
 exports.isLoadBalancerNameRegistered = isLoadBalancerNameRegistered;
-function getFirstUsableConfig(configs, defaultPickFirst = false) {
+function getFirstUsableConfig(configs, fallbackTodefault = false) {
     for (const config of configs) {
@@ -52,4 +74,9 @@ if (config.getLoadBalancerName() in registeredLoadBalancerTypes) {
     }
-    if (defaultPickFirst) {
-        return new load_balancer_pick_first.PickFirstLoadBalancingConfig();
+    if (fallbackTodefault) {
+        if (defaultLoadBalancerType) {
+            return new registeredLoadBalancerTypes[defaultLoadBalancerType].LoadBalancingConfig();
+        }
+        else {
+            return null;
+        }
     }
@@ -61,4 +88,5 @@ else {
 exports.getFirstUsableConfig = getFirstUsableConfig;
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
 function validateLoadBalancingConfig(obj) {
-    if (!(obj !== null && (typeof obj === 'object'))) {
+    if (!(obj !== null && typeof obj === 'object')) {
         throw new Error('Load balancing config must be an object');
@@ -79,7 +107,2 @@ }
 exports.validateLoadBalancingConfig = validateLoadBalancingConfig;
-function registerAll() {
-    load_balancer_pick_first.setup();
-    load_balancer_round_robin.setup();
-}
-exports.registerAll = registerAll;
 //# sourceMappingURL=load-balancer.js.map

build/src/logging.js

@@ -22,3 +22,14 @@ "use strict";
 const constants_1 = require("./constants");
-let _logger = console;
+const DEFAULT_LOGGER = {
+    error: (message, ...optionalParams) => {
+        console.error('E ' + message, ...optionalParams);
+    },
+    info: (message, ...optionalParams) => {
+        console.error('I ' + message, ...optionalParams);
+    },
+    debug: (message, ...optionalParams) => {
+        console.error('D ' + message, ...optionalParams);
+    },
+};
+let _logger = DEFAULT_LOGGER;
 let _logVerbosity = constants_1.LogVerbosity.ERROR;
@@ -53,4 +64,23 @@ const verbosityString = (_b = (_a = process.env.GRPC_NODE_VERBOSITY) !== null && _a !== void 0 ? _a : process.env.GRPC_VERBOSITY) !== null && _b !== void 0 ? _b : '';
 exports.log = (severity, ...args) => {
-    if (severity >= _logVerbosity && typeof _logger.error === 'function') {
-        _logger.error(...args);
+    let logFunction;
+    if (severity >= _logVerbosity) {
+        switch (severity) {
+            case constants_1.LogVerbosity.DEBUG:
+                logFunction = _logger.debug;
+                break;
+            case constants_1.LogVerbosity.INFO:
+                logFunction = _logger.info;
+                break;
+            case constants_1.LogVerbosity.ERROR:
+                logFunction = _logger.error;
+                break;
+        }
+        /* Fall back to _logger.error when other methods are not available for
+         * compatiblity with older behavior that always logged to _logger.error */
+        if (!logFunction) {
+            logFunction = _logger.error;
+        }
+        if (logFunction) {
+            logFunction.bind(_logger)(...args);
+        }
     }
@@ -71,3 +101,4 @@ };
 function trace(severity, tracer, text) {
-    if (!disabledTracers.has(tracer) && (allEnabled || enabledTracers.has(tracer))) {
+    if (!disabledTracers.has(tracer) &&
+        (allEnabled || enabledTracers.has(tracer))) {
         exports.log(severity, new Date().toISOString() + ' | ' + tracer + ' | ' + text);
@@ -74,0 +105,0 @@ }

build/src/max-message-size-filter.d.ts

 /// <reference types="node" />
-import { BaseFilter, Filter, FilterFactory } from "./filter";
-import { Call, WriteObject } from "./call-stream";
-import { ChannelOptions } from "./channel-options";
+import { BaseFilter, Filter, FilterFactory } from './filter';
+import { Call, WriteObject } from './call-stream';
+import { ChannelOptions } from './channel-options';
 export declare class MaxMessageSizeFilter extends BaseFilter implements Filter {
@@ -6,0 +6,0 @@ private readonly options;

build/src/metadata.d.ts

@@ -74,2 +74,9 @@ /// <reference types="node" />
     /**
+     * This modifies the behavior of JSON.stringify to show an object
+     * representation of the metadata map.
+     */
+    toJSON(): {
+        [key: string]: MetadataValue[];
+    };
+    /**
      * Returns a new Metadata object based fields in a given IncomingHttpHeaders
@@ -76,0 +83,0 @@ * object.

build/src/metadata.js

@@ -200,2 +200,13 @@ "use strict";
     /**
+     * This modifies the behavior of JSON.stringify to show an object
+     * representation of the metadata map.
+     */
+    toJSON() {
+        const result = {};
+        for (const [key, values] of this.internalRepr.entries()) {
+            result[key] = values;
+        }
+        return result;
+    }
+    /**
      * Returns a new Metadata object based fields in a given IncomingHttpHeaders
@@ -202,0 +213,0 @@ * object.

build/src/picker.d.ts

@@ -30,3 +30,3 @@ import { Subchannel } from './subchannel';
      */
-    extraFilterFactory: FilterFactory<Filter> | null;
+    extraFilterFactories: FilterFactory<Filter>[];
     onCallStarted: (() => void) | null;
@@ -38,3 +38,3 @@ }
     status: null;
-    extraFilterFactory: FilterFactory<Filter> | null;
+    extraFilterFactories: FilterFactory<Filter>[];
     onCallStarted: (() => void) | null;
@@ -46,3 +46,3 @@ }
     status: null;
-    extraFilterFactory: null;
+    extraFilterFactories: [];
     onCallStarted: null;
@@ -54,3 +54,3 @@ }
     status: StatusObject;
-    extraFilterFactory: null;
+    extraFilterFactories: [];
     onCallStarted: null;
@@ -62,3 +62,3 @@ }
     status: StatusObject;
-    extraFilterFactory: null;
+    extraFilterFactories: [];
     onCallStarted: null;
@@ -65,0 +65,0 @@ }

build/src/picker.js

@@ -51,3 +51,3 @@ "use strict";
             status: this.status,
-            extraFilterFactory: null,
+            extraFilterFactories: [],
             onCallStarted: null,
@@ -82,3 +82,3 @@ };
             status: null,
-            extraFilterFactory: null,
+            extraFilterFactories: [],
             onCallStarted: null,
@@ -85,0 +85,0 @@ };

build/src/resolver-ip.js

@@ -48,3 +48,3 @@ "use strict";
                 details: `Unrecognized scheme ${target.scheme} in IP resolver`,
-                metadata: new metadata_1.Metadata()
+                metadata: new metadata_1.Metadata(),
             };
@@ -60,11 +60,12 @@ return;
                     details: `Failed to parse ${target.scheme} address ${path}`,
-                    metadata: new metadata_1.Metadata()
+                    metadata: new metadata_1.Metadata(),
                 };
                 return;
             }
-            if ((target.scheme === IPV4_SCHEME && !net_1.isIPv4(hostPort.host)) || (target.scheme === IPV6_SCHEME && !net_1.isIPv6(hostPort.host))) {
+            if ((target.scheme === IPV4_SCHEME && !net_1.isIPv4(hostPort.host)) ||
+                (target.scheme === IPV6_SCHEME && !net_1.isIPv6(hostPort.host))) {
                 this.error = {
                     code: constants_1.Status.UNAVAILABLE,
                     details: `Failed to parse ${target.scheme} address ${path}`,
-                    metadata: new metadata_1.Metadata()
+                    metadata: new metadata_1.Metadata(),
                 };
@@ -75,3 +76,3 @@ return;
                 host: hostPort.host,
-                port: (_a = hostPort.port) !== null && _a !== void 0 ? _a : DEFAULT_PORT
+                port: (_a = hostPort.port) !== null && _a !== void 0 ? _a : DEFAULT_PORT,
             });
@@ -78,0 +79,0 @@ }

build/src/resolver.d.ts

 import { MethodConfig, ServiceConfig } from './service-config';
 import { StatusObject } from './call-stream';
-import { SubchannelAddress } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 import { GrpcUri } from './uri-parser';
@@ -8,2 +8,3 @@ import { ChannelOptions } from './channel-options';
 import { Status } from './constants';
+import { Filter, FilterFactory } from './filter';
 export interface CallConfig {
@@ -16,2 +17,3 @@ methodConfig: MethodConfig;
     status: Status;
+    dynamicFilterFactories: FilterFactory<Filter>[];
 }
@@ -103,2 +105,1 @@ /**
 export declare function mapUriDefaultScheme(target: GrpcUri): GrpcUri | null;
-export declare function registerAll(): void;

build/src/resolver.js

@@ -19,6 +19,3 @@ "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-exports.registerAll = exports.mapUriDefaultScheme = exports.getDefaultAuthority = exports.createResolver = exports.registerDefaultScheme = exports.registerResolver = void 0;
-const resolver_dns = require("./resolver-dns");
-const resolver_uds = require("./resolver-uds");
-const resolver_ip = require("./resolver-ip");
+exports.mapUriDefaultScheme = exports.getDefaultAuthority = exports.createResolver = exports.registerDefaultScheme = exports.registerResolver = void 0;
 const uri_parser_1 = require("./uri-parser");
@@ -92,8 +89,2 @@ const registeredResolvers = {};
 exports.mapUriDefaultScheme = mapUriDefaultScheme;
-function registerAll() {
-    resolver_dns.setup();
-    resolver_uds.setup();
-    resolver_ip.setup();
-}
-exports.registerAll = registerAll;
 //# sourceMappingURL=resolver.js.map

build/src/resolving-load-balancer.d.ts

 import { ChannelControlHelper, LoadBalancer, LoadBalancingConfig } from './load-balancer';
 import { ConfigSelector } from './resolver';
 import { StatusObject } from './call-stream';
-import { SubchannelAddress } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 import { GrpcUri } from './uri-parser';
@@ -6,0 +6,0 @@ import { ChannelOptions } from './channel-options';

build/src/resolving-load-balancer.js

@@ -22,3 +22,3 @@ "use strict";
 const service_config_1 = require("./service-config");
-const channel_1 = require("./channel");
+const connectivity_state_1 = require("./connectivity-state");
 const resolver_1 = require("./resolver");
@@ -41,3 +41,3 @@ const picker_1 = require("./picker");
         var _a, _b;
-        const splitName = methodName.split('/').filter(x => x.length > 0);
+        const splitName = methodName.split('/').filter((x) => x.length > 0);
         const service = (_a = splitName[0]) !== null && _a !== void 0 ? _a : '';
@@ -48,7 +48,9 @@ const method = (_b = splitName[1]) !== null && _b !== void 0 ? _b : '';
                 for (const name of methodConfig.name) {
-                    if (name.service === service && (name.method === undefined || name.method === method)) {
+                    if (name.service === service &&
+                        (name.method === undefined || name.method === method)) {
                         return {
                             methodConfig: methodConfig,
                             pickInformation: {},
-                            status: constants_1.Status.OK
+                            status: constants_1.Status.OK,
+                            dynamicFilterFactories: []
                         };
@@ -62,3 +64,4 @@ }
             pickInformation: {},
-            status: constants_1.Status.OK
+            status: constants_1.Status.OK,
+            dynamicFilterFactories: []
         };
@@ -86,3 +89,3 @@ };
         this.onFailedResolution = onFailedResolution;
-        this.latestChildState = channel_1.ConnectivityState.IDLE;
+        this.latestChildState = connectivity_state_1.ConnectivityState.IDLE;
         this.latestChildPicker = new picker_1.QueuePicker(this);
@@ -92,3 +95,3 @@ /**
          */
-        this.currentState = channel_1.ConnectivityState.IDLE;
+        this.currentState = connectivity_state_1.ConnectivityState.IDLE;
         /**
@@ -114,3 +117,3 @@ * The service config object from the last successful resolution, if
         }
-        this.updateState(channel_1.ConnectivityState.IDLE, new picker_1.QueuePicker(this));
+        this.updateState(connectivity_state_1.ConnectivityState.IDLE, new picker_1.QueuePicker(this));
         this.childLoadBalancer = new load_balancer_child_handler_1.ChildLoadBalancerHandler({
@@ -135,2 +138,4 @@ createSubchannel: channelControlHelper.createSubchannel.bind(channelControlHelper),
             },
+            addChannelzChild: channelControlHelper.addChannelzChild.bind(channelControlHelper),
+            removeChannelzChild: channelControlHelper.removeChannelzChild.bind(channelControlHelper)
         });
@@ -201,4 +206,4 @@ this.innerResolver = resolver_1.createResolver(target, {
         this.innerResolver.updateResolution();
-        if (this.currentState === channel_1.ConnectivityState.IDLE) {
-            this.updateState(channel_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
+        if (this.currentState === connectivity_state_1.ConnectivityState.IDLE) {
+            this.updateState(connectivity_state_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
         }
@@ -209,7 +214,7 @@ }
             ' ' +
-            channel_1.ConnectivityState[this.currentState] +
+            connectivity_state_1.ConnectivityState[this.currentState] +
             ' -> ' +
-            channel_1.ConnectivityState[connectivityState]);
+            connectivity_state_1.ConnectivityState[connectivityState]);
         // Ensure that this.exitIdle() is called by the picker
-        if (connectivityState === channel_1.ConnectivityState.IDLE) {
+        if (connectivityState === connectivity_state_1.ConnectivityState.IDLE) {
             picker = new picker_1.QueuePicker(this);
@@ -221,4 +226,4 @@ }
     handleResolutionFailure(error) {
-        if (this.latestChildState === channel_1.ConnectivityState.IDLE) {
-            this.updateState(channel_1.ConnectivityState.TRANSIENT_FAILURE, new picker_1.UnavailablePicker(error));
+        if (this.latestChildState === connectivity_state_1.ConnectivityState.IDLE) {
+            this.updateState(connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE, new picker_1.UnavailablePicker(error));
             this.onFailedResolution(error);
@@ -230,3 +235,3 @@ }
         this.childLoadBalancer.exitIdle();
-        if (this.currentState === channel_1.ConnectivityState.IDLE) {
+        if (this.currentState === connectivity_state_1.ConnectivityState.IDLE) {
             if (this.backoffTimeout.isRunning()) {
@@ -238,3 +243,3 @@ this.continueResolving = true;
             }
-            this.updateState(channel_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
+            this.updateState(connectivity_state_1.ConnectivityState.CONNECTING, new picker_1.QueuePicker(this));
         }
@@ -252,3 +257,3 @@ }
         this.innerResolver.destroy();
-        this.updateState(channel_1.ConnectivityState.SHUTDOWN, new picker_1.UnavailablePicker());
+        this.updateState(connectivity_state_1.ConnectivityState.SHUTDOWN, new picker_1.UnavailablePicker());
     }
@@ -255,0 +260,0 @@ getTypeName() {

build/src/server-call.js

@@ -233,2 +233,4 @@ "use strict";
             this.emit('cancelled', 'cancelled');
+            this.emit('streamEnd', false);
+            this.sendStatus({ code: constants_1.Status.CANCELLED, details: 'Cancelled by client', metadata: new metadata_1.Metadata() });
         });
@@ -314,2 +316,3 @@ this.stream.on('drain', () => {
                     }
+                    this.emit('receiveMessage');
                     resolve(this.deserializeMessage(requestBytes));
@@ -366,2 +369,4 @@ }
         var _a;
+        this.emit('callEnd', statusObj.code);
+        this.emit('streamEnd', statusObj.code === constants_1.Status.OK);
         if (this.checkCancelled()) {
@@ -390,5 +395,2 @@ return;
     sendError(error) {
-        if (this.checkCancelled()) {
-            return;
-        }
         const status = {
@@ -424,2 +426,3 @@ code: constants_1.Status.UNKNOWN,
         this.sendMetadata();
+        this.emit('sendMessage');
         return this.stream.write(chunk);
@@ -449,2 +452,3 @@ }
                 }
+                this.emit('receiveMessage');
                 this.pushOrBufferMessage(readable, message);
@@ -451,0 +455,0 @@ }

build/src/server.d.ts

@@ -5,2 +5,3 @@ import { Deserialize, Serialize, ServiceDefinition } from './make-client';
 import { ChannelOptions } from './channel-options';
+import { ServerRef } from './channelz';
 export declare type UntypedHandleCall = HandleCall<any, any>;
@@ -16,3 +17,11 @@ export interface UntypedServiceImplementation {
     private options;
+    private channelzRef;
+    private channelzTrace;
+    private callTracker;
+    private listenerChildrenTracker;
+    private sessionChildrenTracker;
     constructor(options?: ChannelOptions);
+    private getChannelzInfo;
+    private getChannelzSessionInfoGetter;
+    private trace;
     addProtoService(): void;
@@ -29,3 +38,4 @@ addService(service: ServiceDefinition, implementation: UntypedServiceImplementation): void;
     addHttp2Port(): void;
+    getChannelzRef(): ServerRef;
     private _setupHandlers;
 }

build/src/server.js

@@ -24,10 +24,9 @@ "use strict";
 const server_call_1 = require("./server-call");
+const server_credentials_1 = require("./server-credentials");
 const resolver_1 = require("./resolver");
 const logging = require("./logging");
-const subchannel_1 = require("./subchannel");
+const subchannel_address_1 = require("./subchannel-address");
 const uri_parser_1 = require("./uri-parser");
+const channelz_1 = require("./channelz");
 const TRACER_NAME = 'server';
-function trace(text) {
-    logging.trace(constants_1.LogVerbosity.DEBUG, TRACER_NAME, text);
-}
 function noop() { }
@@ -68,6 +67,68 @@ function getUnimplementedStatusResponse(methodName) {
         this.handlers = new Map();
-        this.sessions = new Set();
+        this.sessions = new Map();
         this.started = false;
+        this.channelzTrace = new channelz_1.ChannelzTrace();
+        this.callTracker = new channelz_1.ChannelzCallTracker();
+        this.listenerChildrenTracker = new channelz_1.ChannelzChildrenTracker();
+        this.sessionChildrenTracker = new channelz_1.ChannelzChildrenTracker();
         this.options = options !== null && options !== void 0 ? options : {};
+        this.channelzRef = channelz_1.registerChannelzServer(() => this.getChannelzInfo());
+        this.channelzTrace.addTrace('CT_INFO', 'Server created');
+        this.trace('Server constructed');
     }
+    getChannelzInfo() {
+        return {
+            trace: this.channelzTrace,
+            callTracker: this.callTracker,
+            listenerChildren: this.listenerChildrenTracker.getChildLists(),
+            sessionChildren: this.sessionChildrenTracker.getChildLists()
+        };
+    }
+    getChannelzSessionInfoGetter(session) {
+        return () => {
+            var _a, _b, _c;
+            const sessionInfo = this.sessions.get(session);
+            const sessionSocket = session.socket;
+            const remoteAddress = sessionSocket.remoteAddress ? subchannel_address_1.stringToSubchannelAddress(sessionSocket.remoteAddress, sessionSocket.remotePort) : null;
+            const localAddress = subchannel_address_1.stringToSubchannelAddress(sessionSocket.localAddress, sessionSocket.localPort);
+            let tlsInfo;
+            if (session.encrypted) {
+                const tlsSocket = sessionSocket;
+                const cipherInfo = tlsSocket.getCipher();
+                const certificate = tlsSocket.getCertificate();
+                const peerCertificate = tlsSocket.getPeerCertificate();
+                tlsInfo = {
+                    cipherSuiteStandardName: (_a = cipherInfo.standardName) !== null && _a !== void 0 ? _a : null,
+                    cipherSuiteOtherName: cipherInfo.standardName ? null : cipherInfo.name,
+                    localCertificate: (certificate && 'raw' in certificate) ? certificate.raw : null,
+                    remoteCertificate: (peerCertificate && 'raw' in peerCertificate) ? peerCertificate.raw : null
+                };
+            }
+            else {
+                tlsInfo = null;
+            }
+            const socketInfo = {
+                remoteAddress: remoteAddress,
+                localAddress: localAddress,
+                security: tlsInfo,
+                remoteName: null,
+                streamsStarted: sessionInfo.streamTracker.callsStarted,
+                streamsSucceeded: sessionInfo.streamTracker.callsSucceeded,
+                streamsFailed: sessionInfo.streamTracker.callsFailed,
+                messagesSent: sessionInfo.messagesSent,
+                messagesReceived: sessionInfo.messagesReceived,
+                keepAlivesSent: 0,
+                lastLocalStreamCreatedTimestamp: null,
+                lastRemoteStreamCreatedTimestamp: sessionInfo.streamTracker.lastCallStartedTimestamp,
+                lastMessageSentTimestamp: sessionInfo.lastMessageSentTimestamp,
+                lastMessageReceivedTimestamp: sessionInfo.lastMessageReceivedTimestamp,
+                localFlowControlWindow: (_b = session.state.localWindowSize) !== null && _b !== void 0 ? _b : null,
+                remoteFlowControlWindow: (_c = session.state.remoteWindowSize) !== null && _c !== void 0 ? _c : null
+            };
+            return socketInfo;
+        };
+    }
+    trace(text) {
+        logging.trace(constants_1.LogVerbosity.DEBUG, TRACER_NAME, '(' + this.channelzRef.id + ') ' + text);
+    }
     addProtoService() {
@@ -124,4 +185,3 @@ throw new Error('Not implemented. Use addService() instead');
     removeService(service) {
-        if (service === null ||
-            typeof service !== 'object') {
+        if (service === null || typeof service !== 'object') {
             throw new Error('removeService() requires object as argument');
@@ -145,4 +205,4 @@ }
         }
-        if (creds === null || typeof creds !== 'object') {
-            throw new TypeError('creds must be an object');
+        if (creds === null || !(creds instanceof server_credentials_1.ServerCredentials)) {
+            throw new TypeError('creds must be a ServerCredentials object');
         }
@@ -161,3 +221,3 @@ if (typeof callback !== 'function') {
         const serverOptions = {
-            maxSendHeaderBlockLength: Number.MAX_SAFE_INTEGER
+            maxSendHeaderBlockLength: Number.MAX_SAFE_INTEGER,
         };
@@ -172,2 +232,5 @@ if ('grpc-node.max_session_memory' in this.options) {
         }
+        const deferredCallback = (error, port) => {
+            process.nextTick(() => callback(error, port));
+        };
         const setupServer = () => {
@@ -191,5 +254,5 @@ let http2Server;
             return Promise.all(addressList.map((address) => {
-                trace('Attempting to bind ' + subchannel_1.subchannelAddressToString(address));
+                this.trace('Attempting to bind ' + subchannel_address_1.subchannelAddressToString(address));
                 let addr;
-                if (subchannel_1.isTcpSubchannelAddress(address)) {
+                if (subchannel_address_1.isTcpSubchannelAddress(address)) {
                     addr = {
@@ -205,16 +268,45 @@ host: address.host,
                 return new Promise((resolve, reject) => {
-                    function onError(err) {
+                    const onError = (err) => {
+                        this.trace('Failed to bind ' + subchannel_address_1.subchannelAddressToString(address) + ' with error ' + err.message);
                         resolve(err);
-                    }
+                    };
                     http2Server.once('error', onError);
                     http2Server.listen(addr, () => {
-                        trace('Successfully bound ' + subchannel_1.subchannelAddressToString(address));
-                        this.http2ServerList.push(http2Server);
                         const boundAddress = http2Server.address();
+                        let boundSubchannelAddress;
                         if (typeof boundAddress === 'string') {
-                            resolve(portNum);
+                            boundSubchannelAddress = {
+                                path: boundAddress
+                            };
                         }
                         else {
-                            resolve(boundAddress.port);
+                            boundSubchannelAddress = {
+                                host: boundAddress.address,
+                                port: boundAddress.port
+                            };
                         }
+                        const channelzRef = channelz_1.registerChannelzSocket(subchannel_address_1.subchannelAddressToString(boundSubchannelAddress), () => {
+                            return {
+                                localAddress: boundSubchannelAddress,
+                                remoteAddress: null,
+                                security: null,
+                                remoteName: null,
+                                streamsStarted: 0,
+                                streamsSucceeded: 0,
+                                streamsFailed: 0,
+                                messagesSent: 0,
+                                messagesReceived: 0,
+                                keepAlivesSent: 0,
+                                lastLocalStreamCreatedTimestamp: null,
+                                lastRemoteStreamCreatedTimestamp: null,
+                                lastMessageSentTimestamp: null,
+                                lastMessageReceivedTimestamp: null,
+                                localFlowControlWindow: null,
+                                remoteFlowControlWindow: null
+                            };
+                        });
+                        this.listenerChildrenTracker.refChild(channelzRef);
+                        this.http2ServerList.push({ server: http2Server, channelzRef: channelzRef });
+                        this.trace('Successfully bound ' + subchannel_address_1.subchannelAddressToString(boundSubchannelAddress));
+                        resolve('port' in boundSubchannelAddress ? boundSubchannelAddress.port : portNum);
                         http2Server.removeListener('error', onError);
@@ -246,9 +338,37 @@ });
             return new Promise((resolve, reject) => {
-                function onError(err) {
+                const onError = (err) => {
+                    this.trace('Failed to bind ' + subchannel_address_1.subchannelAddressToString(address) + ' with error ' + err.message);
                     resolve(bindWildcardPort(addressList.slice(1)));
-                }
+                };
                 http2Server.once('error', onError);
                 http2Server.listen(address, () => {
-                    this.http2ServerList.push(http2Server);
-                    resolve(bindSpecificPort(addressList.slice(1), http2Server.address().port, 1));
+                    const boundAddress = http2Server.address();
+                    const boundSubchannelAddress = {
+                        host: boundAddress.address,
+                        port: boundAddress.port
+                    };
+                    const channelzRef = channelz_1.registerChannelzSocket(subchannel_address_1.subchannelAddressToString(boundSubchannelAddress), () => {
+                        return {
+                            localAddress: boundSubchannelAddress,
+                            remoteAddress: null,
+                            security: null,
+                            remoteName: null,
+                            streamsStarted: 0,
+                            streamsSucceeded: 0,
+                            streamsFailed: 0,
+                            messagesSent: 0,
+                            messagesReceived: 0,
+                            keepAlivesSent: 0,
+                            lastLocalStreamCreatedTimestamp: null,
+                            lastRemoteStreamCreatedTimestamp: null,
+                            lastMessageSentTimestamp: null,
+                            lastMessageReceivedTimestamp: null,
+                            localFlowControlWindow: null,
+                            remoteFlowControlWindow: null
+                        };
+                    });
+                    this.listenerChildrenTracker.refChild(channelzRef);
+                    this.http2ServerList.push({ server: http2Server, channelzRef: channelzRef });
+                    this.trace('Successfully bound ' + subchannel_address_1.subchannelAddressToString(boundSubchannelAddress));
+                    resolve(bindSpecificPort(addressList.slice(1), boundAddress.port, 1));
                     http2Server.removeListener('error', onError);
@@ -263,7 +383,7 @@ });
                 if (addressList.length === 0) {
-                    callback(new Error(`No addresses resolved for port ${port}`), 0);
+                    deferredCallback(new Error(`No addresses resolved for port ${port}`), 0);
                     return;
                 }
                 let bindResultPromise;
-                if (subchannel_1.isTcpSubchannelAddress(addressList[0])) {
+                if (subchannel_address_1.isTcpSubchannelAddress(addressList[0])) {
                     if (addressList[0].port === 0) {
@@ -284,3 +404,3 @@ bindResultPromise = bindWildcardPort(addressList);
                         logging.log(constants_1.LogVerbosity.ERROR, errorString);
-                        callback(new Error(errorString), 0);
+                        deferredCallback(new Error(errorString), 0);
                     }
@@ -291,3 +411,3 @@ else {
                         }
-                        callback(null, bindResult.port);
+                        deferredCallback(null, bindResult.port);
                     }
@@ -297,7 +417,7 @@ }, (error) => {
                     logging.log(constants_1.LogVerbosity.ERROR, errorString);
-                    callback(new Error(errorString), 0);
+                    deferredCallback(new Error(errorString), 0);
                 });
             },
             onError: (error) => {
-                callback(new Error(error.details), 0);
+                deferredCallback(new Error(error.details), 0);
             },
@@ -310,5 +430,8 @@ };
         // Close the server if it is still running.
-        for (const http2Server of this.http2ServerList) {
+        for (const { server: http2Server, channelzRef: ref } of this.http2ServerList) {
             if (http2Server.listening) {
-                http2Server.close();
+                http2Server.close(() => {
+                    this.listenerChildrenTracker.unrefChild(ref);
+                    channelz_1.unregisterChannelzRef(ref);
+                });
             }
@@ -319,3 +442,3 @@ }
         // tryShutdown() calls are in progress. Don't wait on them to finish.
-        this.sessions.forEach((session) => {
+        this.sessions.forEach((channelzInfo, session) => {
             // Cast NGHTTP2_CANCEL to any because TypeScript doesn't seem to
@@ -327,2 +450,3 @@ // recognize destroy(code) as a valid signature.
         this.sessions.clear();
+        channelz_1.unregisterChannelzRef(this.channelzRef);
     }
@@ -347,3 +471,3 @@ register(name, handler, serialize, deserialize, type) {
         if (this.http2ServerList.length === 0 ||
-            this.http2ServerList.every((http2Server) => http2Server.listening !== true)) {
+            this.http2ServerList.every(({ server: http2Server }) => http2Server.listening !== true)) {
             throw new Error('server must be bound in order to start');
@@ -354,5 +478,10 @@ }
         }
+        this.channelzTrace.addTrace('CT_INFO', 'Starting');
         this.started = true;
     }
     tryShutdown(callback) {
+        const wrappedCallback = (error) => {
+            channelz_1.unregisterChannelzRef(this.channelzRef);
+            callback(error);
+        };
         let pendingChecks = 0;
@@ -362,3 +491,3 @@ function maybeCallback() {
             if (pendingChecks === 0) {
-                callback();
+                wrappedCallback();
             }
@@ -368,9 +497,13 @@ }
         this.started = false;
-        for (const http2Server of this.http2ServerList) {
+        for (const { server: http2Server, channelzRef: ref } of this.http2ServerList) {
             if (http2Server.listening) {
                 pendingChecks++;
-                http2Server.close(maybeCallback);
+                http2Server.close(() => {
+                    this.listenerChildrenTracker.unrefChild(ref);
+                    channelz_1.unregisterChannelzRef(ref);
+                    maybeCallback();
+                });
             }
         }
-        this.sessions.forEach((session) => {
+        this.sessions.forEach((channelzInfo, session) => {
             if (!session.closed) {
@@ -382,3 +515,3 @@ pendingChecks += 1;
         if (pendingChecks === 0) {
-            callback();
+            wrappedCallback();
         }
@@ -389,2 +522,5 @@ }
     }
+    getChannelzRef() {
+        return this.channelzRef;
+    }
     _setupHandlers(http2Server) {
@@ -395,2 +531,5 @@ if (http2Server === null) {
         http2Server.on('stream', (stream, headers) => {
+            const channelzSessionInfo = this.sessions.get(stream.session);
+            this.callTracker.addCallStarted();
+            channelzSessionInfo === null || channelzSessionInfo === void 0 ? void 0 : channelzSessionInfo.streamTracker.addCallStarted();
             const contentType = headers[http2.constants.HTTP2_HEADER_CONTENT_TYPE];
@@ -402,4 +541,7 @@ if (typeof contentType !== 'string' ||
                 }, { endStream: true });
+                this.callTracker.addCallFailed();
+                channelzSessionInfo === null || channelzSessionInfo === void 0 ? void 0 : channelzSessionInfo.streamTracker.addCallFailed();
                 return;
             }
+            let call = null;
             try {
@@ -418,3 +560,3 @@ const path = headers[http2.constants.HTTP2_HEADER_PATH];
                 }
-                trace('Received call to method ' +
+                this.trace('Received call to method ' +
                     path +
@@ -425,3 +567,3 @@ ' at address ' +
                 if (handler === undefined) {
-                    trace('No handler registered for method ' +
+                    this.trace('No handler registered for method ' +
                         path +
@@ -431,3 +573,29 @@ '. Sending UNIMPLEMENTED status.');
                 }
-                const call = new server_call_1.Http2ServerCallStream(stream, handler, this.options);
+                call = new server_call_1.Http2ServerCallStream(stream, handler, this.options);
+                call.once('callEnd', (code) => {
+                    if (code === constants_1.Status.OK) {
+                        this.callTracker.addCallSucceeded();
+                    }
+                    else {
+                        this.callTracker.addCallFailed();
+                    }
+                });
+                if (channelzSessionInfo) {
+                    call.once('streamEnd', (success) => {
+                        if (success) {
+                            channelzSessionInfo.streamTracker.addCallSucceeded();
+                        }
+                        else {
+                            channelzSessionInfo.streamTracker.addCallFailed();
+                        }
+                    });
+                    call.on('sendMessage', () => {
+                        channelzSessionInfo.messagesSent += 1;
+                        channelzSessionInfo.lastMessageSentTimestamp = new Date();
+                    });
+                    call.on('receiveMessage', () => {
+                        channelzSessionInfo.messagesReceived += 1;
+                        channelzSessionInfo.lastMessageReceivedTimestamp = new Date();
+                    });
+                }
                 const metadata = call.receiveMetadata(headers);
@@ -452,3 +620,7 @@ switch (handler.type) {
             catch (err) {
-                const call = new server_call_1.Http2ServerCallStream(stream, null, this.options);
+                if (!call) {
+                    call = new server_call_1.Http2ServerCallStream(stream, null, this.options);
+                    this.callTracker.addCallFailed();
+                    channelzSessionInfo === null || channelzSessionInfo === void 0 ? void 0 : channelzSessionInfo.streamTracker.addCallFailed();
+                }
                 if (err.code === undefined) {
@@ -461,2 +633,3 @@ err.code = constants_1.Status.INTERNAL;
         http2Server.on('session', (session) => {
+            var _a;
             if (!this.started) {
@@ -466,4 +639,19 @@ session.destroy();
             }
-            this.sessions.add(session);
+            const channelzRef = channelz_1.registerChannelzSocket((_a = session.socket.remoteAddress) !== null && _a !== void 0 ? _a : 'unknown', this.getChannelzSessionInfoGetter(session));
+            const channelzSessionInfo = {
+                ref: channelzRef,
+                streamTracker: new channelz_1.ChannelzCallTracker(),
+                messagesSent: 0,
+                messagesReceived: 0,
+                lastMessageSentTimestamp: null,
+                lastMessageReceivedTimestamp: null
+            };
+            this.sessions.set(session, channelzSessionInfo);
+            const clientAddress = session.socket.remoteAddress;
+            this.channelzTrace.addTrace('CT_INFO', 'Connection established by client ' + clientAddress);
+            this.sessionChildrenTracker.refChild(channelzRef);
             session.on('close', () => {
+                this.channelzTrace.addTrace('CT_INFO', 'Connection dropped by client ' + clientAddress);
+                this.sessionChildrenTracker.unrefChild(channelzRef);
+                channelz_1.unregisterChannelzRef(channelzRef);
                 this.sessions.delete(session);
@@ -470,0 +658,0 @@ });

build/src/service-config.d.ts

@@ -6,6 +6,10 @@ import { LoadBalancingConfig } from './load-balancer';
 }
+export interface Duration {
+    seconds: number;
+    nanos: number;
+}
 export interface MethodConfig {
     name: MethodConfigName[];
     waitForReady?: boolean;
-    timeout?: string;
+    timeout?: Duration;
     maxRequestBytes?: number;
@@ -12,0 +16,0 @@ maxResponseBytes?: number;

build/src/service-config.js

@@ -59,2 +59,3 @@ "use strict";
 function validateMethodConfig(obj) {
+    var _a;
     const result = {
@@ -76,7 +77,26 @@ name: [],
     if ('timeout' in obj) {
-        if (!(typeof obj.timeout === 'string') ||
-            !TIMEOUT_REGEX.test(obj.timeout)) {
+        if (typeof obj.timeout === 'object') {
+            if (!('seconds' in obj.timeout) ||
+                !(typeof obj.timeout.seconds === 'number')) {
+                throw new Error('Invalid method config: invalid timeout.seconds');
+            }
+            if (!('nanos' in obj.timeout) ||
+                !(typeof obj.timeout.nanos === 'number')) {
+                throw new Error('Invalid method config: invalid timeout.nanos');
+            }
+            result.timeout = obj.timeout;
+        }
+        else if (typeof obj.timeout === 'string' &&
+            TIMEOUT_REGEX.test(obj.timeout)) {
+            const timeoutParts = obj.timeout
+                .substring(0, obj.timeout.length - 1)
+                .split('.');
+            result.timeout = {
+                seconds: timeoutParts[0] | 0,
+                nanos: ((_a = timeoutParts[1]) !== null && _a !== void 0 ? _a : 0) | 0,
+            };
+        }
+        else {
             throw new Error('Invalid method config: invalid timeout');
         }
-        result.timeout = obj.timeout;
     }
@@ -83,0 +103,0 @@ if ('maxRequestBytes' in obj) {

build/src/subchannel-pool.d.ts

 import { ChannelOptions } from './channel-options';
-import { Subchannel, SubchannelAddress } from './subchannel';
+import { Subchannel } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 import { ChannelCredentials } from './channel-credentials';
@@ -4,0 +5,0 @@ import { GrpcUri } from './uri-parser';

build/src/subchannel-pool.js

@@ -22,2 +22,3 @@ "use strict";
 const subchannel_1 = require("./subchannel");
+const subchannel_address_1 = require("./subchannel-address");
 const uri_parser_1 = require("./uri-parser");
@@ -102,3 +103,3 @@ // 10 seconds in milliseconds. This value is arbitrary.
             for (const subchannelObj of subchannelObjArray) {
-                if (subchannel_1.subchannelAddressEqual(subchannelTarget, subchannelObj.subchannelAddress) &&
+                if (subchannel_address_1.subchannelAddressEqual(subchannelTarget, subchannelObj.subchannelAddress) &&
                     channel_options_1.channelOptionsEqual(channelArguments, subchannelObj.channelArguments) &&
@@ -105,0 +106,0 @@ channelCredentials._equals(subchannelObj.channelCredentials)) {

build/src/subchannel.d.ts

@@ -5,23 +5,12 @@ import { ChannelCredentials } from './channel-credentials';
 import { ChannelOptions } from './channel-options';
-import { ConnectivityState } from './channel';
+import { ConnectivityState } from './connectivity-state';
 import { GrpcUri } from './uri-parser';
-import { FilterFactory, Filter } from './filter';
+import { Filter } from './filter';
+import { SubchannelAddress } from './subchannel-address';
+import { SubchannelRef } from './channelz';
 export declare type ConnectivityStateListener = (subchannel: Subchannel, previousState: ConnectivityState, newState: ConnectivityState) => void;
-export interface TcpSubchannelAddress {
-    port: number;
-    host: string;
+export interface SubchannelCallStatsTracker {
+    addMessageSent(): void;
+    addMessageReceived(): void;
 }
-export interface IpcSubchannelAddress {
-    path: string;
-}
-/**
- * This represents a single backend address to connect to. This interface is a
- * subset of net.SocketConnectOpts, i.e. the options described at
- * https://nodejs.org/api/net.html#net_socket_connect_options_connectlistener.
- * Those are in turn a subset of the options that can be passed to http2.connect.
- */
-export declare type SubchannelAddress = TcpSubchannelAddress | IpcSubchannelAddress;
-export declare function isTcpSubchannelAddress(address: SubchannelAddress): address is TcpSubchannelAddress;
-export declare function subchannelAddressEqual(address1: SubchannelAddress, address2: SubchannelAddress): boolean;
-export declare function subchannelAddressToString(address: SubchannelAddress): string;
 export declare class Subchannel {
@@ -95,3 +84,19 @@ private channelTarget;
     private subchannelAddressString;
+    private channelzRef;
+    private channelzTrace;
+    private callTracker;
+    private childrenTracker;
+    private channelzSocketRef;
     /**
+     * Name of the remote server, if it is not the same as the subchannel
+     * address, i.e. if connecting through an HTTP CONNECT proxy.
+     */
+    private remoteName;
+    private streamTracker;
+    private keepalivesSent;
+    private messagesSent;
+    private messagesReceived;
+    private lastMessageSentTimestamp;
+    private lastMessageReceivedTimestamp;
+    /**
      * A class representing a connection to a single backend.
@@ -107,2 +112,7 @@ * @param channelTarget The target string for the channel as a whole
     constructor(channelTarget: GrpcUri, subchannelAddress: SubchannelAddress, options: ChannelOptions, credentials: ChannelCredentials);
+    private getChannelzInfo;
+    private getChannelzSocketInfo;
+    private resetChannelzSocketInfo;
+    private trace;
+    private refTrace;
     private handleBackoffTimer;
@@ -144,3 +154,3 @@ /**
      */
-    startCallStream(metadata: Metadata, callStream: Http2CallStream, extraFilterFactory?: FilterFactory<Filter>): void;
+    startCallStream(metadata: Metadata, callStream: Http2CallStream, extraFilters: Filter[]): void;
     /**
@@ -176,2 +186,3 @@ * If the subchannel is currently IDLE, start connecting and switch to the
     getAddress(): string;
+    getChannelzRef(): SubchannelRef;
 }

build/src/subchannel.js

@@ -19,6 +19,6 @@ "use strict";
 Object.defineProperty(exports, "__esModule", { value: true });
-exports.Subchannel = exports.subchannelAddressToString = exports.subchannelAddressEqual = exports.isTcpSubchannelAddress = void 0;
+exports.Subchannel = void 0;
 const http2 = require("http2");
 const tls_1 = require("tls");
-const channel_1 = require("./channel");
+const connectivity_state_1 = require("./connectivity-state");
 const backoff_timeout_1 = require("./backoff-timeout");
@@ -31,10 +31,6 @@ const resolver_1 = require("./resolver");
 const uri_parser_1 = require("./uri-parser");
+const subchannel_address_1 = require("./subchannel-address");
+const channelz_1 = require("./channelz");
 const clientVersion = require('../../package.json').version;
 const TRACER_NAME = 'subchannel';
-function trace(text) {
-    logging.trace(constants_1.LogVerbosity.DEBUG, TRACER_NAME, text);
-}
-function refTrace(text) {
-    logging.trace(constants_1.LogVerbosity.DEBUG, 'subchannel_refcount', text);
-}
 const MIN_CONNECT_TIMEOUT_MS = 20000;
@@ -60,26 +56,2 @@ const INITIAL_BACKOFF_MS = 1000;
 const tooManyPingsData = Buffer.from('too_many_pings', 'ascii');
-function isTcpSubchannelAddress(address) {
-    return 'port' in address;
-}
-exports.isTcpSubchannelAddress = isTcpSubchannelAddress;
-function subchannelAddressEqual(address1, address2) {
-    if (isTcpSubchannelAddress(address1)) {
-        return (isTcpSubchannelAddress(address2) &&
-            address1.host === address2.host &&
-            address1.port === address2.port);
-    }
-    else {
-        return !isTcpSubchannelAddress(address2) && address1.path === address2.path;
-    }
-}
-exports.subchannelAddressEqual = subchannelAddressEqual;
-function subchannelAddressToString(address) {
-    if (isTcpSubchannelAddress(address)) {
-        return address.host + ':' + address.port;
-    }
-    else {
-        return address.path;
-    }
-}
-exports.subchannelAddressToString = subchannelAddressToString;
 class Subchannel {
@@ -105,3 +77,3 @@ /**
          */
-        this.connectivityState = channel_1.ConnectivityState.IDLE;
+        this.connectivityState = connectivity_state_1.ConnectivityState.IDLE;
         /**
@@ -148,2 +120,17 @@ * The underlying http2 session used to make requests.
         this.refcount = 0;
+        this.callTracker = new channelz_1.ChannelzCallTracker();
+        this.childrenTracker = new channelz_1.ChannelzChildrenTracker();
+        // Channelz socket info
+        this.channelzSocketRef = null;
+        /**
+         * Name of the remote server, if it is not the same as the subchannel
+         * address, i.e. if connecting through an HTTP CONNECT proxy.
+         */
+        this.remoteName = null;
+        this.streamTracker = new channelz_1.ChannelzCallTracker();
+        this.keepalivesSent = 0;
+        this.messagesSent = 0;
+        this.messagesReceived = 0;
+        this.lastMessageSentTimestamp = null;
+        this.lastMessageReceivedTimestamp = null;
         // Build user-agent string.
@@ -164,3 +151,4 @@ this.userAgent = [
         if ('grpc.keepalive_permit_without_calls' in options) {
-            this.keepaliveWithoutCalls = options['grpc.keepalive_permit_without_calls'] === 1;
+            this.keepaliveWithoutCalls =
+                options['grpc.keepalive_permit_without_calls'] === 1;
         }
@@ -181,11 +169,87 @@ else {
         }, backoffOptions);
-        this.subchannelAddressString = subchannelAddressToString(subchannelAddress);
-        trace('Subchannel constructed with options ' + JSON.stringify(options, undefined, 2));
+        this.subchannelAddressString = subchannel_address_1.subchannelAddressToString(subchannelAddress);
+        this.channelzRef = channelz_1.registerChannelzSubchannel(this.subchannelAddressString, () => this.getChannelzInfo());
+        this.channelzTrace = new channelz_1.ChannelzTrace();
+        this.channelzTrace.addTrace('CT_INFO', 'Subchannel created');
+        this.trace('Subchannel constructed with options ' + JSON.stringify(options, undefined, 2));
     }
+    getChannelzInfo() {
+        return {
+            state: this.connectivityState,
+            trace: this.channelzTrace,
+            callTracker: this.callTracker,
+            children: this.childrenTracker.getChildLists(),
+            target: this.subchannelAddressString
+        };
+    }
+    getChannelzSocketInfo() {
+        var _a, _b, _c;
+        if (this.session === null) {
+            return null;
+        }
+        const sessionSocket = this.session.socket;
+        const remoteAddress = sessionSocket.remoteAddress ? subchannel_address_1.stringToSubchannelAddress(sessionSocket.remoteAddress, sessionSocket.remotePort) : null;
+        const localAddress = subchannel_address_1.stringToSubchannelAddress(sessionSocket.localAddress, sessionSocket.localPort);
+        let tlsInfo;
+        if (this.session.encrypted) {
+            const tlsSocket = sessionSocket;
+            const cipherInfo = tlsSocket.getCipher();
+            const certificate = tlsSocket.getCertificate();
+            const peerCertificate = tlsSocket.getPeerCertificate();
+            tlsInfo = {
+                cipherSuiteStandardName: (_a = cipherInfo.standardName) !== null && _a !== void 0 ? _a : null,
+                cipherSuiteOtherName: cipherInfo.standardName ? null : cipherInfo.name,
+                localCertificate: (certificate && 'raw' in certificate) ? certificate.raw : null,
+                remoteCertificate: (peerCertificate && 'raw' in peerCertificate) ? peerCertificate.raw : null
+            };
+        }
+        else {
+            tlsInfo = null;
+        }
+        const socketInfo = {
+            remoteAddress: remoteAddress,
+            localAddress: localAddress,
+            security: tlsInfo,
+            remoteName: this.remoteName,
+            streamsStarted: this.streamTracker.callsStarted,
+            streamsSucceeded: this.streamTracker.callsSucceeded,
+            streamsFailed: this.streamTracker.callsFailed,
+            messagesSent: this.messagesSent,
+            messagesReceived: this.messagesReceived,
+            keepAlivesSent: this.keepalivesSent,
+            lastLocalStreamCreatedTimestamp: this.streamTracker.lastCallStartedTimestamp,
+            lastRemoteStreamCreatedTimestamp: null,
+            lastMessageSentTimestamp: this.lastMessageSentTimestamp,
+            lastMessageReceivedTimestamp: this.lastMessageReceivedTimestamp,
+            localFlowControlWindow: (_b = this.session.state.localWindowSize) !== null && _b !== void 0 ? _b : null,
+            remoteFlowControlWindow: (_c = this.session.state.remoteWindowSize) !== null && _c !== void 0 ? _c : null
+        };
+        return socketInfo;
+    }
+    resetChannelzSocketInfo() {
+        if (this.channelzSocketRef) {
+            channelz_1.unregisterChannelzRef(this.channelzSocketRef);
+            this.childrenTracker.unrefChild(this.channelzSocketRef);
+            this.channelzSocketRef = null;
+        }
+        this.remoteName = null;
+        this.streamTracker = new channelz_1.ChannelzCallTracker();
+        this.keepalivesSent = 0;
+        this.messagesSent = 0;
+        this.messagesReceived = 0;
+        this.lastMessageSentTimestamp = null;
+        this.lastMessageReceivedTimestamp = null;
+    }
+    trace(text) {
+        logging.trace(constants_1.LogVerbosity.DEBUG, TRACER_NAME, '(' + this.channelzRef.id + ') ' + this.subchannelAddressString + ' ' + text);
+    }
+    refTrace(text) {
+        logging.trace(constants_1.LogVerbosity.DEBUG, 'subchannel_refcount', '(' + this.channelzRef.id + ') ' + this.subchannelAddressString + ' ' + text);
+    }
     handleBackoffTimer() {
         if (this.continueConnecting) {
-            this.transitionToState([channel_1.ConnectivityState.TRANSIENT_FAILURE], channel_1.ConnectivityState.CONNECTING);
+            this.transitionToState([connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE], connectivity_state_1.ConnectivityState.CONNECTING);
         }
         else {
-            this.transitionToState([channel_1.ConnectivityState.TRANSIENT_FAILURE], channel_1.ConnectivityState.IDLE);
+            this.transitionToState([connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE], connectivity_state_1.ConnectivityState.IDLE);
         }
@@ -205,5 +269,7 @@ }
         var _a, _b;
-        logging.trace(constants_1.LogVerbosity.DEBUG, 'keepalive', 'Sending ping to ' + this.subchannelAddressString);
+        this.keepalivesSent += 1;
+        logging.trace(constants_1.LogVerbosity.DEBUG, 'keepalive', '(' + this.channelzRef.id + ') ' + this.subchannelAddressString + ' ' +
+            'Sending ping');
         this.keepaliveTimeoutId = setTimeout(() => {
-            this.transitionToState([channel_1.ConnectivityState.READY], channel_1.ConnectivityState.IDLE);
+            this.transitionToState([connectivity_state_1.ConnectivityState.READY], connectivity_state_1.ConnectivityState.IDLE);
         }, this.keepaliveTimeoutMs);
@@ -231,6 +297,8 @@ (_b = (_a = this.keepaliveTimeoutId).unref) === null || _b === void 0 ? void 0 : _b.call(_a);
         if (proxyConnectionResult.realTarget) {
-            trace(this.subchannelAddressString + ' creating HTTP/2 session through proxy to ' + proxyConnectionResult.realTarget);
+            this.remoteName = uri_parser_1.uriToString(proxyConnectionResult.realTarget);
+            this.trace('creating HTTP/2 session through proxy to ' + proxyConnectionResult.realTarget);
         }
         else {
-            trace(this.subchannelAddressString + ' creating HTTP/2 session');
+            this.remoteName = null;
+            this.trace('creating HTTP/2 session');
         }
@@ -308,2 +376,4 @@ const targetAuthority = resolver_1.getDefaultAuthority((_a = proxyConnectionResult.realTarget) !== null && _a !== void 0 ? _a : this.channelTarget);
         this.session = session;
+        this.channelzSocketRef = channelz_1.registerChannelzSocket(this.subchannelAddressString, () => this.getChannelzSocketInfo());
+        this.childrenTracker.refChild(this.channelzSocketRef);
         session.unref();
@@ -316,3 +386,3 @@ /* For all of these events, check if the session at the time of the event
             if (this.session === session) {
-                this.transitionToState([channel_1.ConnectivityState.CONNECTING], channel_1.ConnectivityState.READY);
+                this.transitionToState([connectivity_state_1.ConnectivityState.CONNECTING], connectivity_state_1.ConnectivityState.READY);
             }
@@ -322,8 +392,8 @@ });
             if (this.session === session) {
-                trace(this.subchannelAddressString + ' connection closed');
-                this.transitionToState([channel_1.ConnectivityState.CONNECTING], channel_1.ConnectivityState.TRANSIENT_FAILURE);
+                this.trace('connection closed');
+                this.transitionToState([connectivity_state_1.ConnectivityState.CONNECTING], connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE);
                 /* Transitioning directly to IDLE here should be OK because we are not
                  * doing any backoff, because a connection was established at some
                  * point */
-                this.transitionToState([channel_1.ConnectivityState.READY], channel_1.ConnectivityState.IDLE);
+                this.transitionToState([connectivity_state_1.ConnectivityState.READY], connectivity_state_1.ConnectivityState.IDLE);
             }
@@ -340,6 +410,5 @@ });
                 }
-                trace(this.subchannelAddressString +
-                    ' connection closed by GOAWAY with code ' +
+                this.trace('connection closed by GOAWAY with code ' +
                     errorCode);
-                this.transitionToState([channel_1.ConnectivityState.CONNECTING, channel_1.ConnectivityState.READY], channel_1.ConnectivityState.IDLE);
+                this.transitionToState([connectivity_state_1.ConnectivityState.CONNECTING, connectivity_state_1.ConnectivityState.READY], connectivity_state_1.ConnectivityState.IDLE);
             }
@@ -350,6 +419,6 @@ });
              * where we want to handle that.  */
-            trace(this.subchannelAddressString +
-                ' connection closed with error ' +
+            this.trace('connection closed with error ' +
                 error.message);
         });
+        channelz_1.registerChannelzSocket(this.subchannelAddressString, () => this.getChannelzSocketInfo());
     }
@@ -392,3 +461,3 @@ startConnectingInternal() {
         }, (reason) => {
-            this.transitionToState([channel_1.ConnectivityState.CONNECTING], channel_1.ConnectivityState.TRANSIENT_FAILURE);
+            this.transitionToState([connectivity_state_1.ConnectivityState.CONNECTING], connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE);
         });
@@ -407,11 +476,10 @@ }
         }
-        trace(this.subchannelAddressString +
-            ' ' +
-            channel_1.ConnectivityState[this.connectivityState] +
+        this.trace(connectivity_state_1.ConnectivityState[this.connectivityState] +
             ' -> ' +
-            channel_1.ConnectivityState[newState]);
+            connectivity_state_1.ConnectivityState[newState]);
+        this.channelzTrace.addTrace('CT_INFO', connectivity_state_1.ConnectivityState[this.connectivityState] + ' -> ' + connectivity_state_1.ConnectivityState[newState]);
         const previousState = this.connectivityState;
         this.connectivityState = newState;
         switch (newState) {
-            case channel_1.ConnectivityState.READY:
+            case connectivity_state_1.ConnectivityState.READY:
                 this.stopBackoff();
@@ -427,3 +495,3 @@ this.session.socket.once('close', () => {
                 break;
-            case channel_1.ConnectivityState.CONNECTING:
+            case connectivity_state_1.ConnectivityState.CONNECTING:
                 this.startBackoff();
@@ -433,3 +501,3 @@ this.startConnectingInternal();
                 break;
-            case channel_1.ConnectivityState.TRANSIENT_FAILURE:
+            case connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE:
                 if (this.session) {
@@ -439,2 +507,3 @@ this.session.close();
                 this.session = null;
+                this.resetChannelzSocketInfo();
                 this.stopKeepalivePings();
@@ -450,3 +519,3 @@ /* If the backoff timer has already ended by the time we get to the
                 break;
-            case channel_1.ConnectivityState.IDLE:
+            case connectivity_state_1.ConnectivityState.IDLE:
                 if (this.session) {
@@ -456,2 +525,3 @@ this.session.close();
                 this.session = null;
+                this.resetChannelzSocketInfo();
                 this.stopKeepalivePings();
@@ -477,11 +547,9 @@ break;
         if (this.callRefcount === 0 && this.refcount === 0) {
-            this.transitionToState([
-                channel_1.ConnectivityState.CONNECTING,
-                channel_1.ConnectivityState.READY,
-            ], channel_1.ConnectivityState.TRANSIENT_FAILURE);
+            this.channelzTrace.addTrace('CT_INFO', 'Shutting down');
+            this.transitionToState([connectivity_state_1.ConnectivityState.CONNECTING, connectivity_state_1.ConnectivityState.READY], connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE);
+            channelz_1.unregisterChannelzRef(this.channelzRef);
         }
     }
     callRef() {
-        refTrace(this.subchannelAddressString +
-            ' callRefcount ' +
+        this.refTrace('callRefcount ' +
             this.callRefcount +
@@ -502,4 +570,3 @@ ' -> ' +
     callUnref() {
-        refTrace(this.subchannelAddressString +
-            ' callRefcount ' +
+        this.refTrace('callRefcount ' +
             this.callRefcount +
@@ -521,4 +588,3 @@ ' -> ' +
     ref() {
-        refTrace(this.subchannelAddressString +
-            ' refcount ' +
+        this.refTrace('refcount ' +
             this.refcount +
@@ -530,4 +596,3 @@ ' -> ' +
     unref() {
-        refTrace(this.subchannelAddressString +
-            ' refcount ' +
+        this.refTrace('refcount ' +
             this.refcount +
@@ -553,3 +618,3 @@ ' -> ' +
      */
-    startCallStream(metadata, callStream, extraFilterFactory) {
+    startCallStream(metadata, callStream, extraFilters) {
         const headers = metadata.toHttp2Headers();
@@ -575,3 +640,3 @@ headers[HTTP2_HEADER_AUTHORITY] = callStream.getHost();
         catch (e) {
-            this.transitionToState([channel_1.ConnectivityState.READY], channel_1.ConnectivityState.TRANSIENT_FAILURE);
+            this.transitionToState([connectivity_state_1.ConnectivityState.READY], connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE);
             throw e;
@@ -583,4 +648,37 @@ }
         }
-        logging.trace(constants_1.LogVerbosity.DEBUG, 'call_stream', 'Starting stream on subchannel ' + this.subchannelAddressString + ' with headers\n' + headersString);
-        callStream.attachHttp2Stream(http2Stream, this, extraFilterFactory);
+        logging.trace(constants_1.LogVerbosity.DEBUG, 'call_stream', 'Starting stream on subchannel ' +
+            '(' + this.channelzRef.id + ') ' +
+            this.subchannelAddressString +
+            ' with headers\n' +
+            headersString);
+        this.callTracker.addCallStarted();
+        callStream.addStatusWatcher(status => {
+            if (status.code === constants_1.Status.OK) {
+                this.callTracker.addCallSucceeded();
+            }
+            else {
+                this.callTracker.addCallFailed();
+            }
+        });
+        const streamSession = this.session;
+        this.streamTracker.addCallStarted();
+        callStream.addStreamEndWatcher(success => {
+            if (streamSession === this.session) {
+                if (success) {
+                    this.streamTracker.addCallSucceeded();
+                }
+                else {
+                    this.streamTracker.addCallFailed();
+                }
+            }
+        });
+        callStream.attachHttp2Stream(http2Stream, this, extraFilters, {
+            addMessageSent: () => {
+                this.messagesSent += 1;
+                this.lastMessageSentTimestamp = new Date();
+            },
+            addMessageReceived: () => {
+                this.messagesReceived += 1;
+            }
+        });
     }
@@ -598,4 +696,4 @@ /**
          * connecting after the backoff timer ends. Otherwise do nothing */
-        if (!this.transitionToState([channel_1.ConnectivityState.IDLE], channel_1.ConnectivityState.CONNECTING)) {
-            if (this.connectivityState === channel_1.ConnectivityState.TRANSIENT_FAILURE) {
+        if (!this.transitionToState([connectivity_state_1.ConnectivityState.IDLE], connectivity_state_1.ConnectivityState.CONNECTING)) {
+            if (this.connectivityState === connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE) {
                 this.continueConnecting = true;
@@ -644,3 +742,3 @@ }
         this.backoffTimeout.reset();
-        this.transitionToState([channel_1.ConnectivityState.TRANSIENT_FAILURE], channel_1.ConnectivityState.CONNECTING);
+        this.transitionToState([connectivity_state_1.ConnectivityState.TRANSIENT_FAILURE], connectivity_state_1.ConnectivityState.CONNECTING);
     }
@@ -650,4 +748,7 @@ getAddress() {
     }
+    getChannelzRef() {
+        return this.channelzRef;
+    }
 }
 exports.Subchannel = Subchannel;
 //# sourceMappingURL=subchannel.js.map

package.json

 {
   "name": "@grpc/grpc-js",
-  "version": "1.3.8",
+  "version": "1.4.0",
   "description": "gRPC Library for Node - pure JS implementation",
@@ -18,3 +18,2 @@ "homepage": "https://grpc.io/",
   "devDependencies": {
-    "@grpc/proto-loader": "^0.5.5",
     "@types/gulp": "^4.0.6",
@@ -33,2 +32,3 @@ "@types/gulp-mocha": "0.0.32",
     "lodash": "^4.17.4",
+    "madge": "^5.0.1",
     "mocha-jenkins-reporter": "^0.4.1",
@@ -58,5 +58,7 @@ "ncp": "^2.0.0",
     "pretest": "npm run compile",
-    "posttest": "npm run check"
+    "posttest": "npm run check && madge -c ./build/src",
+    "generate-types": "proto-loader-gen-types --keepCase --longs String --enums String --defaults --oneofs --includeComments --includeDirs proto/ -O src/generated/ --grpcLib ../index channelz.proto"
   },
   "dependencies": {
+    "@grpc/proto-loader": "^0.6.4",
     "@types/node": ">=12.12.47"
@@ -63,0 +65,0 @@ },

README.md

@@ -28,2 +28,4 @@ # Pure JavaScript gRPC Client
 
+If you need a feature from the `grpc` package that is not provided by the `@grpc/grpc-js`, please file a feature request with that information.
+
 This library does not directly handle `.proto` files. To use `.proto` files with this library we recommend using the `@grpc/proto-loader` package.
@@ -30,0 +32,0 @@

src/call-credentials-filter.ts

@@ -69,3 +69,5 @@ /*
       );
-      return Promise.reject<Metadata>('"authorization" metadata cannot have multiple values');
+      return Promise.reject<Metadata>(
+        '"authorization" metadata cannot have multiple values'
+      );
     }
@@ -72,0 +74,0 @@ return resultMetadata;

src/call-stream.ts

@@ -28,3 +28,3 @@ /*
 import { ChannelImplementation } from './channel';
-import { Subchannel } from './subchannel';
+import { SubchannelCallStatsTracker, Subchannel } from './subchannel';
 import * as logging from './logging';
@@ -61,3 +61,3 @@ import { LogVerbosity } from './constants';
  * own.
- * @param errno 
+ * @param errno
  */
@@ -75,2 +75,14 @@ function getSystemErrorName(errno: number): string {
 
+function getMinDeadline(deadlineList: Deadline[]): Deadline {
+  let minValue = Infinity;
+  for (const deadline of deadlineList) {
+    const deadlineMsecs =
+      deadline instanceof Date ? deadline.getTime() : deadline;
+    if (deadlineMsecs < minValue) {
+      minValue = deadlineMsecs;
+    }
+  }
+  return minValue;
+}
+
 export interface CallStreamOptions {
@@ -205,3 +217,3 @@ deadline: Deadline;
   credentials: CallCredentials;
-  filterStack: Filter;
+  filterStack: FilterStack;
   private http2Stream: http2.ClientHttp2Stream | null = null;
@@ -242,2 +254,9 @@ private pendingRead = false;
 
+  private configDeadline: Deadline = Infinity;
+
+  private statusWatchers: ((status: StatusObject) => void)[] = [];
+  private streamEndWatchers: ((success: boolean) => void)[] = [];
+
+  private callStatsTracker: SubchannelCallStatsTracker | null = null;
+
   constructor(
@@ -260,3 +279,6 @@ private readonly methodName: string,
     };
-    if (this.options.parentCall && this.options.flags & Propagate.CANCELLATION) {
+    if (
+      this.options.parentCall &&
+      this.options.flags & Propagate.CANCELLATION
+    ) {
       this.options.parentCall.on('cancelled', () => {
@@ -275,2 +297,3 @@ this.cancelWithStatus(Status.CANCELLED, 'Cancelled by parent call');
       );
+      this.statusWatchers.forEach(watcher => watcher(filteredStatus));
       /* We delay the actual action of bubbling up the status to insulate the
@@ -419,2 +442,3 @@ * cleanup code in this class from any errors that may be thrown in the
   private handleTrailers(headers: http2.IncomingHttpHeaders) {
+    this.streamEndWatchers.forEach(watcher => watcher(true));
     let headersString = '';
@@ -457,13 +481,14 @@ for (const header of Object.keys(headers)) {
 
+  private writeMessageToStream(message: Buffer, callback: WriteCallback) {
+    this.callStatsTracker?.addMessageSent();
+    this.http2Stream!.write(message, callback);
+  }
+
   attachHttp2Stream(
     stream: http2.ClientHttp2Stream,
     subchannel: Subchannel,
-    extraFilterFactory?: FilterFactory<Filter>
+    extraFilters: Filter[],
+    callStatsTracker: SubchannelCallStatsTracker
   ): void {
-    if (extraFilterFactory !== undefined) {
-      this.filterStack = new FilterStack([
-        this.filterStack,
-        extraFilterFactory.createFilter(this),
-      ]);
-    }
+    this.filterStack.push(extraFilters);
     if (this.finalStatus !== null) {
@@ -477,2 +502,3 @@ stream.close(NGHTTP2_CANCEL);
       this.subchannel = subchannel;
+      this.callStatsTracker = callStatsTracker;
       subchannel.addDisconnectListener(this.disconnectListener);
@@ -543,2 +569,3 @@ subchannel.callRef();
           this.trace('parsed message of length ' + message.length);
+          this.callStatsTracker!.addMessageReceived();
           this.tryPush(message);
@@ -554,3 +581,3 @@ }
          * "error" event that may be emitted at about the same time, so that
-         * we can bubble up the error message from that event. */ 
+         * we can bubble up the error message from that event. */
         process.nextTick(() => {
@@ -604,3 +631,3 @@ this.trace('HTTP/2 stream closed with code ' + stream.rstCode);
               } else {
-                if (this.internalError.code === 'ECONNRESET') {
+                if (this.internalError.code === 'ECONNRESET' || this.internalError.code === 'ETIMEDOUT') {
                   code = Status.UNAVAILABLE;
@@ -637,5 +664,15 @@ details = this.internalError.message;
         if (err.code !== 'ERR_HTTP2_STREAM_ERROR') {
-          this.trace('Node error event: message=' + err.message + ' code=' + err.code + ' errno=' + getSystemErrorName(err.errno) + ' syscall=' + err.syscall);
+          this.trace(
+            'Node error event: message=' +
+              err.message +
+              ' code=' +
+              err.code +
+              ' errno=' +
+              getSystemErrorName(err.errno) +
+              ' syscall=' +
+              err.syscall
+          );
           this.internalError = err;
         }
+        this.streamEndWatchers.forEach(watcher => watcher(false));
       });
@@ -655,3 +692,3 @@ if (!this.pendingRead) {
         try {
-          stream.write(this.pendingWrite, this.pendingWriteCallback);
+          this.writeMessageToStream(this.pendingWrite, this.pendingWriteCallback);
         } catch (error) {
@@ -701,11 +738,10 @@ this.endCall({
   getDeadline(): Deadline {
+    const deadlineList = [this.options.deadline];
     if (this.options.parentCall && this.options.flags & Propagate.DEADLINE) {
-      const parentDeadline = this.options.parentCall.getDeadline();
-      const selfDeadline = this.options.deadline;
-      const parentDeadlineMsecs = parentDeadline instanceof Date ? parentDeadline.getTime() : parentDeadline;
-      const selfDeadlineMsecs = selfDeadline instanceof Date ? selfDeadline.getTime() : selfDeadline;
-      return Math.min(parentDeadlineMsecs, selfDeadlineMsecs);
-    } else {
-      return this.options.deadline;
+      deadlineList.push(this.options.parentCall.getDeadline());
     }
+    if (this.configDeadline) {
+      deadlineList.push(this.configDeadline);
+    }
+    return getMinDeadline(deadlineList);
   }
@@ -737,2 +773,18 @@
 
+  setConfigDeadline(configDeadline: Deadline) {
+    this.configDeadline = configDeadline;
+  }
+
+  addStatusWatcher(watcher: (status: StatusObject) => void) {
+    this.statusWatchers.push(watcher);
+  }
+
+  addStreamEndWatcher(watcher: (success: boolean) => void) {
+    this.streamEndWatchers.push(watcher);
+  }
+
+  addFilters(extraFilters: Filter[]) {
+    this.filterStack.push(extraFilters);
+  }
+
   startRead() {
@@ -791,3 +843,3 @@ /* If the stream has ended with an error, we should not emit any more
         try {
-          this.http2Stream.write(message.message, cb);
+        this.writeMessageToStream(message.message, cb);
         }  catch (error) {
@@ -794,0 +846,0 @@ this.endCall({

src/call.ts

@@ -84,3 +84,4 @@ /*
 
-export class ClientUnaryCallImpl extends EventEmitter
+export class ClientUnaryCallImpl
+  extends EventEmitter
   implements ClientUnaryCall {
@@ -101,3 +102,4 @@ public call?: InterceptingCallInterface;
 
-export class ClientReadableStreamImpl<ResponseType> extends Readable
+export class ClientReadableStreamImpl<ResponseType>
+  extends Readable
   implements ClientReadableStream<ResponseType> {
@@ -122,3 +124,4 @@ public call?: InterceptingCallInterface;
 
-export class ClientWritableStreamImpl<RequestType> extends Writable
+export class ClientWritableStreamImpl<RequestType>
+  extends Writable
   implements ClientWritableStream<RequestType> {
@@ -155,3 +158,4 @@ public call?: InterceptingCallInterface;
 
-export class ClientDuplexStreamImpl<RequestType, ResponseType> extends Duplex
+export class ClientDuplexStreamImpl<RequestType, ResponseType>
+  extends Duplex
   implements ClientDuplexStream<RequestType, ResponseType> {
@@ -158,0 +162,0 @@ public call?: InterceptingCallInterface;

src/channel-options.ts

@@ -40,2 +40,3 @@ /*
   'grpc-node.max_session_memory'?: number;
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   [key: string]: any;
@@ -42,0 +43,0 @@ }

src/channel.ts

@@ -36,5 +36,10 @@ /*
 import { CompressionFilterFactory } from './compression-filter';
-import { CallConfig, ConfigSelector, getDefaultAuthority, mapUriDefaultScheme } from './resolver';
+import {
+  CallConfig,
+  ConfigSelector,
+  getDefaultAuthority,
+  mapUriDefaultScheme,
+} from './resolver';
 import { trace, log } from './logging';
-import { SubchannelAddress } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 import { MaxMessageSizeFilterFactory } from './max-message-size-filter';
@@ -45,10 +50,6 @@ import { mapProxyName } from './http_proxy';
 import { SurfaceCall } from './call';
+import { Filter } from './filter';
 
-export enum ConnectivityState {
-  IDLE,
-  CONNECTING,
-  READY,
-  TRANSIENT_FAILURE,
-  SHUTDOWN,
-}
+import { ConnectivityState } from './connectivity-state';
+import { ChannelInfo, ChannelRef, ChannelzCallTracker, ChannelzChildrenTracker, ChannelzTrace, registerChannelzChannel, SubchannelRef, unregisterChannelzRef } from './channelz';
 
@@ -110,2 +111,8 @@ /**
   /**
+   * Get the channelz reference object for this channel. A request to the
+   * channelz service for the id in this object will provide information
+   * about this channel.
+   */
+  getChannelzRef(): ChannelRef;
+  /**
    * Create a call object. Call is an opaque type that is used by the Client
@@ -154,2 +161,3 @@ * class. This function is called by the gRPC library when starting a
     callConfig: CallConfig;
+    dynamicFilters: Filter[];
   }> = [];
@@ -169,2 +177,10 @@ private connectivityStateWatchers: ConnectivityStateWatcher[] = [];
   private configSelector: ConfigSelector | null = null;
+
+  // Channelz info
+  private originalTarget: string;
+  private channelzRef: ChannelRef;
+  private channelzTrace: ChannelzTrace;
+  private callTracker = new ChannelzCallTracker();
+  private childrenTracker = new ChannelzChildrenTracker();
+
   constructor(
@@ -184,16 +200,7 @@ target: string,
     if (options) {
-      if (
-        typeof options !== 'object' ||
-        !Object.values(options).every(
-          (value) =>
-            typeof value === 'string' ||
-            typeof value === 'number' ||
-            typeof value === 'undefined'
-        )
-      ) {
-        throw new TypeError(
-          'Channel options must be an object with string or number values'
-        );
+      if (typeof options !== 'object') {
+        throw new TypeError('Channel options must be an object');
       }
     }
+    this.originalTarget = target;
     const originalTargetUri = parseUri(target);
@@ -215,2 +222,6 @@ if (originalTargetUri === null) {
 
+    this.channelzRef = registerChannelzChannel(target, () => this.getChannelzInfo());
+    this.channelzTrace = new ChannelzTrace();
+    this.channelzTrace.addTrace('CT_INFO', 'Channel created');
+
     if (this.options['grpc.default_authority']) {
@@ -235,3 +246,3 @@ this.defaultAuthority = this.options['grpc.default_authority'] as string;
       ) => {
-        return this.subchannelPool.getOrCreateSubchannel(
+        const subchannel = this.subchannelPool.getOrCreateSubchannel(
           this.target,
@@ -242,2 +253,4 @@ subchannelAddress,
         );
+        this.channelzTrace.addTrace('CT_INFO', 'Created subchannel or used existing subchannel', subchannel.getChannelzRef());
+        return subchannel;
       },
@@ -249,4 +262,4 @@ updateState: (connectivityState: ConnectivityState, picker: Picker) => {
         this.callRefTimerUnref();
-        for (const { callStream, callMetadata, callConfig } of queueCopy) {
-          this.tryPick(callStream, callMetadata, callConfig);
+        for (const { callStream, callMetadata, callConfig, dynamicFilters } of queueCopy) {
+          this.tryPick(callStream, callMetadata, callConfig, dynamicFilters);
         }
@@ -261,2 +274,8 @@ this.updateState(connectivityState);
       },
+      addChannelzChild: (child: ChannelRef | SubchannelRef) => {
+        this.childrenTracker.refChild(child);
+      },
+      removeChannelzChild: (child: ChannelRef | SubchannelRef) => {
+        this.childrenTracker.unrefChild(child);
+      }
     };
@@ -268,2 +287,3 @@ this.resolvingLoadBalancer = new ResolvingLoadBalancer(
       (configSelector) => {
+        this.channelzTrace.addTrace('CT_INFO', 'Address resolution succeeded');
         this.configSelector = configSelector;
@@ -275,4 +295,4 @@ /* We process the queue asynchronously to ensure that the corresponding
           this.configSelectionQueue = [];
-          this.callRefTimerUnref()
-          for (const {callStream, callMetadata} of localQueue) {
+          this.callRefTimerUnref();
+          for (const { callStream, callMetadata } of localQueue) {
             this.tryGetConfig(callStream, callMetadata);
@@ -284,4 +304,5 @@ }
       (status) => {
+        this.channelzTrace.addTrace('CT_WARNING', 'Address resolution failed with code ' + status.code + ' and details "' + status.details + '"');
         if (this.configSelectionQueue.length > 0) {
-          trace(LogVerbosity.DEBUG, 'channel', 'Name resolution failed for target ' + uriToString(this.target) + ' with calls queued for config selection');
+          this.trace('Name resolution failed with calls queued for config selection');
         }
@@ -291,6 +312,6 @@ const localQueue = this.configSelectionQueue;
         this.callRefTimerUnref();
-        for (const {callStream, callMetadata} of localQueue) {
+        for (const { callStream, callMetadata } of localQueue) {
           if (callMetadata.getOptions().waitForReady) {
             this.callRefTimerRef();
-            this.configSelectionQueue.push({callStream, callMetadata});
+            this.configSelectionQueue.push({ callStream, callMetadata });
           } else {
@@ -308,9 +329,28 @@ callStream.cancelWithStatus(status.code, status.details);
     ]);
-    trace(LogVerbosity.DEBUG, 'channel', 'Channel constructed with options ' + JSON.stringify(options, undefined, 2));
+    this.trace('Channel constructed with options ' + JSON.stringify(options, undefined, 2));
   }
 
+  private getChannelzInfo(): ChannelInfo {
+    return {
+      target: this.originalTarget,
+      state: this.connectivityState,
+      trace: this.channelzTrace,
+      callTracker: this.callTracker,
+      children: this.childrenTracker.getChildLists()
+    };
+  }
+
+  private trace(text: string, verbosityOverride?: LogVerbosity) {
+    trace(verbosityOverride ?? LogVerbosity.DEBUG, 'channel', '(' + this.channelzRef.id + ') ' + uriToString(this.target) + ' ' + text);
+  }
+
   private callRefTimerRef() {
     // If the hasRef function does not exist, always run the code
     if (!this.callRefTimer.hasRef?.()) {
-      trace(LogVerbosity.DEBUG, 'channel', 'callRefTimer.ref | configSelectionQueue.length=' + this.configSelectionQueue.length + ' pickQueue.length=' + this.pickQueue.length);
+      this.trace(
+        'callRefTimer.ref | configSelectionQueue.length=' +
+          this.configSelectionQueue.length +
+          ' pickQueue.length=' +
+          this.pickQueue.length
+      );
       this.callRefTimer.ref?.();
@@ -322,4 +362,9 @@ }
     // If the hasRef function does not exist, always run the code
-    if ((!this.callRefTimer.hasRef) || (this.callRefTimer.hasRef())) {
-      trace(LogVerbosity.DEBUG, 'channel', 'callRefTimer.unref | configSelectionQueue.length=' + this.configSelectionQueue.length + ' pickQueue.length=' + this.pickQueue.length);
+    if (!this.callRefTimer.hasRef || this.callRefTimer.hasRef()) {
+      this.trace(
+        'callRefTimer.unref | configSelectionQueue.length=' +
+          this.configSelectionQueue.length +
+          ' pickQueue.length=' +
+          this.pickQueue.length
+      );
       this.callRefTimer.unref?.();
@@ -329,4 +374,9 @@ }
 
-  private pushPick(callStream: Http2CallStream, callMetadata: Metadata, callConfig: CallConfig) {
-    this.pickQueue.push({ callStream, callMetadata, callConfig });
+  private pushPick(
+    callStream: Http2CallStream,
+    callMetadata: Metadata,
+    callConfig: CallConfig,
+    dynamicFilters: Filter[]
+  ) {
+    this.pickQueue.push({ callStream, callMetadata, callConfig, dynamicFilters });
     this.callRefTimerRef();
@@ -342,7 +392,13 @@ }
    */
-  private tryPick(callStream: Http2CallStream, callMetadata: Metadata, callConfig: CallConfig) {
-    const pickResult = this.currentPicker.pick({ metadata: callMetadata, extraPickInfo: callConfig.pickInformation });
-    trace(
-      LogVerbosity.DEBUG,
-      'channel',
+  private tryPick(
+    callStream: Http2CallStream,
+    callMetadata: Metadata,
+    callConfig: CallConfig,
+    dynamicFilters: Filter[]
+  ) {
+    const pickResult = this.currentPicker.pick({
+      metadata: callMetadata,
+      extraPickInfo: callConfig.pickInformation,
+    });
+    this.trace(
       'Pick result: ' +
@@ -380,3 +436,3 @@ PickResultType[pickResult.pickResultType] +
             );
-            this.pushPick(callStream, callMetadata, callConfig);
+            this.pushPick(callStream, callMetadata, callConfig, dynamicFilters);
             break;
@@ -394,6 +450,7 @@ }
                   try {
+                    const pickExtraFilters = pickResult.extraFilterFactories.map(factory => factory.createFilter(callStream));
                     pickResult.subchannel!.startCallStream(
                       finalMetadata,
                       callStream,
-                      pickResult.extraFilterFactory ?? undefined
+                      [...dynamicFilters, ...pickExtraFilters]
                     );
@@ -422,5 +479,3 @@ /* If we reach this point, the call stream has started
                        * tryPick */
-                      trace(
-                        LogVerbosity.INFO,
-                        'channel',
+                      this.trace(
                         'Failed to start call on picked subchannel ' +
@@ -430,9 +485,8 @@ pickResult.subchannel!.getAddress() +
                           (error as Error).message +
-                          '. Retrying pick'
+                          '. Retrying pick',
+                          LogVerbosity.INFO
                       );
-                      this.tryPick(callStream, callMetadata, callConfig);
+                      this.tryPick(callStream, callMetadata, callConfig, dynamicFilters);
                     } else {
-                      trace(
-                        LogVerbosity.INFO,
-                        'channel',
+                      this.trace(
                         'Failed to start call on picked subchanel ' +
@@ -442,7 +496,10 @@ pickResult.subchannel!.getAddress() +
                           (error as Error).message +
-                          '. Ending call'
+                          '. Ending call',
+                          LogVerbosity.INFO
                       );
                       callStream.cancelWithStatus(
                         Status.INTERNAL,
-                        `Failed to start HTTP/2 stream with error: ${(error as Error).message}`
+                        `Failed to start HTTP/2 stream with error: ${
+                          (error as Error).message
+                        }`
                       );
@@ -454,5 +511,3 @@ }
                    * block above */
-                  trace(
-                    LogVerbosity.INFO,
-                    'channel',
+                  this.trace(
                     'Picked subchannel ' +
@@ -462,5 +517,6 @@ pickResult.subchannel!.getAddress() +
                       ConnectivityState[subchannelState] +
-                      ' after metadata filters. Retrying pick'
+                      ' after metadata filters. Retrying pick',
+                      LogVerbosity.INFO
                   );
-                  this.tryPick(callStream, callMetadata, callConfig);
+                  this.tryPick(callStream, callMetadata, callConfig, dynamicFilters);
                 }
@@ -471,3 +527,3 @@ },
                 callStream.cancelWithStatus(
-                  (typeof error.code === 'number') ? error.code : Status.UNKNOWN,
+                  typeof error.code === 'number' ? error.code : Status.UNKNOWN,
                   `Getting metadata from plugin failed with error: ${error.message}`
@@ -480,7 +536,7 @@ );
       case PickResultType.QUEUE:
-        this.pushPick(callStream, callMetadata, callConfig);
+        this.pushPick(callStream, callMetadata, callConfig, dynamicFilters);
         break;
       case PickResultType.TRANSIENT_FAILURE:
         if (callMetadata.getOptions().waitForReady) {
-          this.pushPick(callStream, callMetadata, callConfig);
+          this.pushPick(callStream, callMetadata, callConfig, dynamicFilters);
         } else {
@@ -521,3 +577,4 @@ callStream.cancelWithStatus(
       'connectivity_state',
-      uriToString(this.target) +
+      '(' + this.channelzRef.id + ') ' + 
+        uriToString(this.target) +
         ' ' +
@@ -528,2 +585,3 @@ ConnectivityState[this.connectivityState] +
     );
+    this.channelzTrace.addTrace('CT_INFO', ConnectivityState[this.connectivityState] + ' -> ' + ConnectivityState[newState]);
     this.connectivityState = newState;
@@ -533,3 +591,3 @@ const watchersCopy = this.connectivityStateWatchers.slice();
       if (newState !== watcherObject.currentState) {
-        if(watcherObject.timer) {
+        if (watcherObject.timer) {
           clearTimeout(watcherObject.timer);
@@ -544,2 +602,7 @@ }
   private tryGetConfig(stream: Http2CallStream, metadata: Metadata) {
+    if (stream.getStatus() !== null) {
+      /* If the stream has a status, it has already finished and we don't need
+       * to take any more actions on it. */
+      return;
+    }
     if (this.configSelector === null) {
@@ -551,5 +614,5 @@ /* This branch will only be taken at the beginning of the channel's life,
       this.resolvingLoadBalancer.exitIdle();
-      this.configSelectionQueue.push({ 
+      this.configSelectionQueue.push({
         callStream: stream,
-        callMetadata: metadata
+        callMetadata: metadata,
       });
@@ -560,5 +623,41 @@ this.callRefTimerRef();
       if (callConfig.status === Status.OK) {
-        this.tryPick(stream, metadata, callConfig);
+        if (callConfig.methodConfig.timeout) {
+          const deadline = new Date();
+          deadline.setSeconds(
+            deadline.getSeconds() + callConfig.methodConfig.timeout.seconds
+          );
+          deadline.setMilliseconds(
+            deadline.getMilliseconds() +
+              callConfig.methodConfig.timeout.nanos / 1_000_000
+          );
+          stream.setConfigDeadline(deadline);
+          // Refreshing the filters makes the deadline filter pick up the new deadline
+          stream.filterStack.refresh();
+        }
+        if (callConfig.dynamicFilterFactories.length > 0) {
+          /* These dynamicFilters are the mechanism for implementing gRFC A39:
+           * https://github.com/grpc/proposal/blob/master/A39-xds-http-filters.md
+           * We run them here instead of with the rest of the filters because
+           * that spec says "the xDS HTTP filters will run in between name 
+           * resolution and load balancing".
+           * 
+           * We use the filter stack here to simplify the multi-filter async
+           * waterfall logic, but we pass along the underlying list of filters
+           * to avoid having nested filter stacks when combining it with the
+           * original filter stack. We do not pass along the original filter
+           * factory list because these filters may need to persist data
+           * between sending headers and other operations. */
+          const dynamicFilterStackFactory = new FilterStackFactory(callConfig.dynamicFilterFactories);
+          const dynamicFilterStack = dynamicFilterStackFactory.createFilter(stream);
+          dynamicFilterStack.sendMetadata(Promise.resolve(metadata)).then(filteredMetadata => {
+            this.tryPick(stream, filteredMetadata, callConfig, dynamicFilterStack.getFilters());
+          });
+        } else {
+          this.tryPick(stream, metadata, callConfig, []);
+        }
       } else {
-        stream.cancelWithStatus(callConfig.status, "Failed to route call to method " + stream.getMethod());
+        stream.cancelWithStatus(
+          callConfig.status,
+          'Failed to route call to method ' + stream.getMethod()
+        );
       }
@@ -576,2 +675,3 @@ }
     clearInterval(this.callRefTimer);
+    unregisterChannelzRef(this.channelzRef);
 
@@ -602,3 +702,3 @@ this.subchannelPool.unrefUnusedSubchannels();
     let timer = null;
-    if(deadline !== Infinity) {
+    if (deadline !== Infinity) {
       const deadlineDate: Date =
@@ -619,3 +719,3 @@ deadline instanceof Date ? deadline : new Date(deadline);
         );
-      }, deadlineDate.getTime() - now.getTime())
+      }, deadlineDate.getTime() - now.getTime());
     }
@@ -625,3 +725,3 @@ const watcherObject = {
       callback,
-      timer
+      timer,
     };
@@ -631,2 +731,6 @@ this.connectivityStateWatchers.push(watcherObject);
 
+  getChannelzRef() {
+    return this.channelzRef;
+  }
+
   createCall(
@@ -651,7 +755,4 @@ method: string,
     const callNumber = getNewCallNumber();
-    trace(
-      LogVerbosity.DEBUG,
-      'channel',
-      uriToString(this.target) +
-        ' createCall [' +
+    this.trace(
+      'createCall [' +
         callNumber +
@@ -677,4 +778,12 @@ '] method="' +
     );
+    this.callTracker.addCallStarted();
+    stream.addStatusWatcher(status => {
+      if (status.code === Status.OK) {
+        this.callTracker.addCallSucceeded();
+      } else {
+        this.callTracker.addCallFailed();
+      }
+    });
     return stream;
   }
 }

src/client-interceptors.ts

@@ -351,3 +351,6 @@ /*
     } catch (e) {
-      this.call.cancelWithStatus(Status.INTERNAL, `Request message serialization failure: ${e.message}`);
+      this.call.cancelWithStatus(
+        Status.INTERNAL,
+        `Request message serialization failure: ${e.message}`
+      );
       return;
@@ -407,3 +410,4 @@ }
  */
-class BaseUnaryInterceptingCall extends BaseInterceptingCall
+class BaseUnaryInterceptingCall
+  extends BaseInterceptingCall
   implements InterceptingCallInterface {
@@ -440,3 +444,4 @@ // eslint-disable-next-line @typescript-eslint/no-explicit-any
  */
-class BaseStreamingInterceptingCall extends BaseInterceptingCall
+class BaseStreamingInterceptingCall
+  extends BaseInterceptingCall
   implements InterceptingCallInterface {}
@@ -443,0 +448,0 @@

src/client.ts

@@ -33,3 +33,4 @@ /*
 import { Deadline, StatusObject } from './call-stream';
-import { Channel, ConnectivityState, ChannelImplementation } from './channel';
+import { Channel, ChannelImplementation } from './channel';
+import { ConnectivityState } from './connectivity-state';
 import { ChannelCredentials } from './channel-credentials';
@@ -59,3 +60,5 @@ import { ChannelOptions } from './channel-options';
 
-function isFunction<ResponseType>(arg: Metadata | CallOptions | UnaryCallback<ResponseType> | undefined): arg is UnaryCallback<ResponseType>{
+function isFunction<ResponseType>(
+  arg: Metadata | CallOptions | UnaryCallback<ResponseType> | undefined
+): arg is UnaryCallback<ResponseType> {
   return typeof arg === 'function';
@@ -270,5 +273,7 @@ }
   ): ClientUnaryCall {
-    const checkedArguments = this.checkOptionalUnaryResponseArguments<
-      ResponseType
-    >(metadata, options, callback);
+    const checkedArguments = this.checkOptionalUnaryResponseArguments<ResponseType>(
+      metadata,
+      options,
+      callback
+    );
     const methodDefinition: ClientMethodDefinition<
@@ -387,5 +392,7 @@ RequestType,
   ): ClientWritableStream<RequestType> {
-    const checkedArguments = this.checkOptionalUnaryResponseArguments<
-      ResponseType
-    >(metadata, options, callback);
+    const checkedArguments = this.checkOptionalUnaryResponseArguments<ResponseType>(
+      metadata,
+      options,
+      callback
+    );
     const methodDefinition: ClientMethodDefinition<
@@ -414,5 +421,3 @@ RequestType,
     }
-    const emitter: ClientWritableStream<RequestType> = callProperties.call as ClientWritableStream<
-      RequestType
-    >;
+    const emitter: ClientWritableStream<RequestType> = callProperties.call as ClientWritableStream<RequestType>;
     const interceptorArgs: InterceptorArguments = {
@@ -539,5 +544,3 @@ clientInterceptors: this[INTERCEPTOR_SYMBOL],
     }
-    const stream: ClientReadableStream<ResponseType> = callProperties.call as ClientReadableStream<
-      ResponseType
-    >;
+    const stream: ClientReadableStream<ResponseType> = callProperties.call as ClientReadableStream<ResponseType>;
     const interceptorArgs: InterceptorArguments = {
@@ -667,3 +670,3 @@ clientInterceptors: this[INTERCEPTOR_SYMBOL],
       onReceiveMessage(message: Buffer) {
-        stream.push(message)
+        stream.push(message);
       },
@@ -685,2 +688,1 @@ onReceiveStatus(status: StatusObject) {
 }
-

src/constants.ts

@@ -55,3 +55,7 @@ /*
   // https://github.com/grpc/grpc/blob/master/include/grpc/impl/codegen/propagation_bits.h#L43
-  DEFAULTS = 0xffff | Propagate.DEADLINE | Propagate.CENSUS_STATS_CONTEXT | Propagate.CENSUS_TRACING_CONTEXT | Propagate.CANCELLATION,
+  DEFAULTS = 0xffff |
+    Propagate.DEADLINE |
+    Propagate.CENSUS_STATS_CONTEXT |
+    Propagate.CENSUS_TRACING_CONTEXT |
+    Propagate.CANCELLATION,
 }
@@ -58,0 +62,0 @@

src/deadline-filter.ts

@@ -45,3 +45,3 @@ /*
   private timer: NodeJS.Timer | null = null;
-  private deadline: number;
+  private deadline = Infinity;
   constructor(
@@ -52,3 +52,8 @@ private readonly channel: Channel,
     super();
-    const callDeadline = callStream.getDeadline();
+    this.retreiveDeadline();
+    this.runTimer();
+  }
+
+  private retreiveDeadline() {
+    const callDeadline = this.callStream.getDeadline();
     if (callDeadline instanceof Date) {
@@ -59,7 +64,13 @@ this.deadline = callDeadline.getTime();
     }
+  }
+
+  private runTimer() {
+    if (this.timer) {
+      clearTimeout(this.timer);
+    }
     const now: number = new Date().getTime();
-    let timeout = this.deadline - now;
+    const timeout = this.deadline - now;
     if (timeout <= 0) {
       process.nextTick(() => {
-        callStream.cancelWithStatus(
+        this.callStream.cancelWithStatus(
           Status.DEADLINE_EXCEEDED,
@@ -71,3 +82,3 @@ 'Deadline exceeded'
       this.timer = setTimeout(() => {
-        callStream.cancelWithStatus(
+        this.callStream.cancelWithStatus(
           Status.DEADLINE_EXCEEDED,
@@ -81,2 +92,7 @@ 'Deadline exceeded'
 
+  refresh() {
+    this.retreiveDeadline();
+    this.runTimer();
+  }
+
   async sendMetadata(metadata: Promise<Metadata>) {
@@ -83,0 +99,0 @@ if (this.deadline === Infinity) {

src/experimental.ts

 export { trace } from './logging';
-export { Resolver, ResolverListener, registerResolver, ConfigSelector } from './resolver';
+export {
+  Resolver,
+  ResolverListener,
+  registerResolver,
+  ConfigSelector,
+} from './resolver';
 export { GrpcUri, uriToString } from './uri-parser';
-export { ServiceConfig } from './service-config';
+export { ServiceConfig, Duration } from './service-config';
 export { BackoffTimeout } from './backoff-timeout';
-export { LoadBalancer, LoadBalancingConfig, ChannelControlHelper, registerLoadBalancerType, getFirstUsableConfig, validateLoadBalancingConfig } from './load-balancer';
-export { SubchannelAddress, subchannelAddressToString } from './subchannel';
+export {
+  LoadBalancer,
+  LoadBalancingConfig,
+  ChannelControlHelper,
+  createChildChannelControlHelper,
+  registerLoadBalancerType,
+  getFirstUsableConfig,
+  validateLoadBalancingConfig,
+} from './load-balancer';
+export {
+  SubchannelAddress,
+  subchannelAddressToString,
+} from './subchannel-address';
 export { ChildLoadBalancerHandler } from './load-balancer-child-handler';
-export { Picker, UnavailablePicker, QueuePicker, PickResult, PickArgs, PickResultType } from './picker';
+export {
+  Picker,
+  UnavailablePicker,
+  QueuePicker,
+  PickResult,
+  PickArgs,
+  PickResultType,
+} from './picker';
 export { Call as CallStream } from './call-stream';
 export { Filter, BaseFilter, FilterFactory } from './filter';
-export { FilterStackFactory } from './filter-stack';
+export { FilterStackFactory } from './filter-stack';
+export { registerAdminService } from './admin';

src/filter-stack.ts

@@ -74,2 +74,16 @@ /*
   }
+
+  refresh(): void {
+    for (const filter of this.filters) {
+      filter.refresh();
+    }
+  }
+
+  push(filters: Filter[]) {
+    this.filters.unshift(...filters);
+  }
+
+  getFilters(): Filter[] {
+    return this.filters;
+  }
 }
@@ -80,2 +94,6 @@
 
+  push(filterFactories: FilterFactory<Filter>[]) {
+    this.factories.unshift(...filterFactories);
+  }
+
   createFilter(callStream: Call): FilterStack {
@@ -82,0 +100,0 @@ return new FilterStack(

src/filter.ts

@@ -35,2 +35,4 @@ /*
   receiveTrailers(status: StatusObject): StatusObject;
+
+  refresh(): void;
 }
@@ -58,2 +60,4 @@
   }
+
+  refresh(): void {}
 }
@@ -60,0 +64,0 @@

src/http_proxy.ts

@@ -29,3 +29,3 @@ /*
   subchannelAddressToString,
-} from './subchannel';
+} from './subchannel-address';
 import { ChannelOptions } from './channel-options';
@@ -97,3 +97,3 @@ import { GrpcUri, parseUri, splitHostPort, uriToString } from './uri-parser';
   const result: ProxyInfo = {
-    address: `${hostname}:${port}`
+    address: `${hostname}:${port}`,
   };
@@ -152,3 +152,5 @@ if (userCred) {
     if (host === serverHost) {
-      trace('Not using proxy for target in no_proxy list: ' + uriToString(target));
+      trace(
+        'Not using proxy for target in no_proxy list: ' + uriToString(target)
+      );
       return noProxyResult;
@@ -194,2 +196,5 @@ }
   };
+  const headers: http.OutgoingHttpHeaders = {
+    Host: parsedTarget.path,
+  };
   // Connect to the subchannel address as a proxy
@@ -203,10 +208,9 @@ if (isTcpSubchannelAddress(address)) {
   if ('grpc.http_connect_creds' in channelOptions) {
-    options.headers = {
-      'Proxy-Authorization':
-        'Basic ' +
-        Buffer.from(
-          channelOptions['grpc.http_connect_creds'] as string
-        ).toString('base64'),
-    };
+    headers['Proxy-Authorization'] =
+      'Basic ' +
+      Buffer.from(
+        channelOptions['grpc.http_connect_creds'] as string
+      ).toString('base64');
   }
+  options.headers = headers
   const proxyAddressString = subchannelAddressToString(address);
@@ -234,3 +238,3 @@ trace('Using proxy ' + proxyAddressString + ' to connect to ' + options.path);
           const remoteHost = hostPort?.host ?? targetPath;
-          
+
           const cts = tls.connect(
@@ -237,0 +241,0 @@ {

src/index.ts

@@ -27,3 +27,4 @@ /*
 import { Deadline, StatusObject } from './call-stream';
-import { Channel, ConnectivityState, ChannelImplementation } from './channel';
+import { Channel, ChannelImplementation } from './channel';
+import { ConnectivityState } from './connectivity-state';
 import { ChannelCredentials } from './channel-credentials';
@@ -66,2 +67,3 @@ import {
   ServerDuplexStream,
+  ServerErrorResponse,
 } from './server-call';
@@ -178,2 +180,3 @@
   ServerDuplexStream,
+  ServerErrorResponse,
   ServiceDefinition,
@@ -186,3 +189,8 @@ UntypedHandleCall,
 
-export { handleBidiStreamingCall, handleServerStreamingCall, handleUnaryCall, handleClientStreamingCall };
+export {
+  handleBidiStreamingCall,
+  handleServerStreamingCall,
+  handleUnaryCall,
+  handleClientStreamingCall,
+};
 
@@ -248,7 +256,18 @@ /* eslint-disable @typescript-eslint/no-explicit-any */
 
+export {
+  getChannelzServiceDefinition,
+  getChannelzHandlers
+} from './channelz';
+
+export { addAdminServicesToServer } from './admin';
+
 import * as experimental from './experimental';
 export { experimental };
 
-import * as resolver from './resolver';
-import * as load_balancer from './load-balancer';
+import * as resolver_dns from './resolver-dns';
+import * as resolver_uds from './resolver-uds';
+import * as resolver_ip from './resolver-ip';
+import * as load_balancer_pick_first from './load-balancer-pick-first';
+import * as load_balancer_round_robin from './load-balancer-round-robin';
+import * as channelz from './channelz';
 
@@ -259,4 +278,8 @@ const clientVersion = require('../../package.json').version;
   logging.trace(LogVerbosity.DEBUG, 'index', 'Loading @grpc/grpc-js version ' + clientVersion);
-  resolver.registerAll();
-  load_balancer.registerAll();
+  resolver_dns.setup();
+  resolver_uds.setup();
+  resolver_ip.setup();
+  load_balancer_pick_first.setup();
+  load_balancer_round_robin.setup();
+  channelz.setup();
 })();

src/load-balancer-child-handler.ts

@@ -21,9 +21,11 @@ /*
   ChannelControlHelper,
+  LoadBalancingConfig,
   createLoadBalancer,
-  LoadBalancingConfig
 } from './load-balancer';
-import { SubchannelAddress, Subchannel } from './subchannel';
+import { Subchannel } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 import { ChannelOptions } from './channel-options';
-import { ConnectivityState } from './channel';
+import { ConnectivityState } from './connectivity-state';
 import { Picker } from './picker';
+import { ChannelRef, SubchannelRef } from './channelz';
 
@@ -70,2 +72,9 @@ const TYPE_NAME = 'child_load_balancer_helper';
     }
+    addChannelzChild(child: ChannelRef | SubchannelRef) {
+      this.parent.channelControlHelper.addChannelzChild(child);
+    }
+    removeChannelzChild(child: ChannelRef | SubchannelRef) {
+      this.parent.channelControlHelper.removeChannelzChild(child);
+    }
+    
     private calledByPendingChild(): boolean {
@@ -72,0 +81,0 @@ return this.child === this.parent.pendingChild;

src/load-balancer-pick-first.ts

@@ -21,6 +21,7 @@ /*
   ChannelControlHelper,
+  LoadBalancingConfig,
+  registerDefaultLoadBalancerType,
   registerLoadBalancerType,
-  LoadBalancingConfig
 } from './load-balancer';
-import { ConnectivityState } from './channel';
+import { ConnectivityState } from './connectivity-state';
 import {
@@ -34,8 +35,7 @@ QueuePicker,
 } from './picker';
+import { Subchannel, ConnectivityStateListener } from './subchannel';
 import {
-  Subchannel,
-  ConnectivityStateListener,
   SubchannelAddress,
   subchannelAddressToString,
-} from './subchannel';
+} from './subchannel-address';
 import * as logging from './logging';
@@ -67,6 +67,7 @@ import { LogVerbosity } from './constants';
     return {
-      [TYPE_NAME]: {}
+      [TYPE_NAME]: {},
     };
   }
 
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   static createFromJson(obj: any) {
@@ -89,3 +90,3 @@ return new PickFirstLoadBalancingConfig();
       status: null,
-      extraFilterFactory: null,
+      extraFilterFactories: [],
       onCallStarted: null,
@@ -235,2 +236,3 @@ };
         );
+        this.channelControlHelper.removeChannelzChild(subchannel.getChannelzRef());
         if (this.subchannels.length > 0) {
@@ -328,2 +330,3 @@ if (this.triedAllSubchannels) {
     subchannel.ref();
+    this.channelControlHelper.addChannelzChild(subchannel.getChannelzRef());
     this.resetSubchannelList();
@@ -347,2 +350,3 @@ clearTimeout(this.connectionDelayTimeout);
       subchannel.unref();
+      this.channelControlHelper.removeChannelzChild(subchannel.getChannelzRef());
     }
@@ -378,2 +382,3 @@ this.currentSubchannelIndex = 0;
       subchannel.ref();
+      this.channelControlHelper.addChannelzChild(subchannel.getChannelzRef());
     }
@@ -459,2 +464,3 @@ for (const subchannel of this.subchannels) {
       );
+      this.channelControlHelper.removeChannelzChild(this.currentPick.getChannelzRef());
     }
@@ -469,3 +475,8 @@ }
 export function setup(): void {
-  registerLoadBalancerType(TYPE_NAME, PickFirstLoadBalancer, PickFirstLoadBalancingConfig);
+  registerLoadBalancerType(
+    TYPE_NAME,
+    PickFirstLoadBalancer,
+    PickFirstLoadBalancingConfig
+  );
+  registerDefaultLoadBalancerType(TYPE_NAME);
 }

src/load-balancer-round-robin.ts

@@ -21,6 +21,6 @@ /*
   ChannelControlHelper,
+  LoadBalancingConfig,
   registerLoadBalancerType,
-  LoadBalancingConfig
 } from './load-balancer';
-import { ConnectivityState } from './channel';
+import { ConnectivityState } from './connectivity-state';
 import {
@@ -34,8 +34,7 @@ QueuePicker,
 } from './picker';
+import { Subchannel, ConnectivityStateListener } from './subchannel';
 import {
-  Subchannel,
-  ConnectivityStateListener,
   SubchannelAddress,
   subchannelAddressToString,
-} from './subchannel';
+} from './subchannel-address';
 import * as logging from './logging';
@@ -61,6 +60,7 @@ import { LogVerbosity } from './constants';
     return {
-      [TYPE_NAME]: {}
+      [TYPE_NAME]: {},
     };
   }
 
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   static createFromJson(obj: any) {
@@ -84,3 +84,3 @@ return new RoundRobinLoadBalancingConfig();
       status: null,
-      extraFilterFactory: null,
+      extraFilterFactories: [],
       onCallStarted: null,
@@ -135,3 +135,3 @@ };
       this.calculateAndUpdateState();
-      
+
       if (
@@ -199,2 +199,3 @@ newState === ConnectivityState.TRANSIENT_FAILURE ||
       subchannel.unref();
+      this.channelControlHelper.removeChannelzChild(subchannel.getChannelzRef());
     }
@@ -226,2 +227,3 @@ this.subchannelStateCounts = {
       subchannel.addConnectivityStateListener(this.subchannelStateListener);
+      this.channelControlHelper.addChannelzChild(subchannel.getChannelzRef());
       const subchannelState = subchannel.getConnectivityState();
@@ -257,3 +259,7 @@ this.subchannelStateCounts[subchannelState] += 1;
 export function setup() {
-  registerLoadBalancerType(TYPE_NAME, RoundRobinLoadBalancer, RoundRobinLoadBalancingConfig);
+  registerLoadBalancerType(
+    TYPE_NAME,
+    RoundRobinLoadBalancer,
+    RoundRobinLoadBalancingConfig
+  );
 }

src/load-balancer.ts

@@ -19,7 +19,7 @@ /*
 import { ChannelOptions } from './channel-options';
-import { Subchannel, SubchannelAddress } from './subchannel';
-import { ConnectivityState } from './channel';
+import { Subchannel } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
+import { ConnectivityState } from './connectivity-state';
 import { Picker } from './picker';
-import * as load_balancer_pick_first from './load-balancer-pick-first';
-import * as load_balancer_round_robin from './load-balancer-round-robin';
+import { ChannelRef, SubchannelRef } from './channelz';
 
@@ -52,5 +52,25 @@ /**
   requestReresolution(): void;
+  addChannelzChild(child: ChannelRef | SubchannelRef): void;
+  removeChannelzChild(child: ChannelRef | SubchannelRef): void;
 }
 
 /**
+ * Create a child ChannelControlHelper that overrides some methods of the
+ * parent while letting others pass through to the parent unmodified. This
+ * allows other code to create these children without needing to know about
+ * all of the methods to be passed through.
+ * @param parent 
+ * @param overrides 
+ */
+export function createChildChannelControlHelper(parent: ChannelControlHelper, overrides: Partial<ChannelControlHelper>): ChannelControlHelper {
+  return {
+    createSubchannel: overrides.createSubchannel?.bind(overrides) ?? parent.createSubchannel.bind(parent),
+    updateState: overrides.updateState?.bind(overrides) ?? parent.updateState.bind(parent),
+    requestReresolution: overrides.requestReresolution?.bind(overrides) ?? parent.requestReresolution.bind(parent),
+    addChannelzChild: overrides.addChannelzChild?.bind(overrides) ?? parent.addChannelzChild.bind(parent),
+    removeChannelzChild: overrides.removeChannelzChild?.bind(overrides) ?? parent.removeChannelzChild.bind(parent)
+  };
+}
+
+/**
  * Tracks one or more connected subchannels and determines which subchannel
@@ -107,3 +127,5 @@ * each request should use.
 export interface LoadBalancingConfigConstructor {
-  new(...args: any): LoadBalancingConfig;
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  new (...args: any): LoadBalancingConfig;
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   createFromJson(obj: any): LoadBalancingConfig;
@@ -114,7 +136,9 @@ }
   [name: string]: {
-    LoadBalancer: LoadBalancerConstructor,
-    LoadBalancingConfig: LoadBalancingConfigConstructor
+    LoadBalancer: LoadBalancerConstructor;
+    LoadBalancingConfig: LoadBalancingConfigConstructor;
   };
 } = {};
 
+let defaultLoadBalancerType: string | null = null;
+
 export function registerLoadBalancerType(
@@ -127,6 +151,10 @@ typeName: string,
     LoadBalancer: loadBalancerType,
-    LoadBalancingConfig: loadBalancingConfigType
+    LoadBalancingConfig: loadBalancingConfigType,
   };
 }
 
+export function registerDefaultLoadBalancerType(typeName: string) {
+  defaultLoadBalancerType = typeName;
+}
+
 export function createLoadBalancer(
@@ -138,3 +166,5 @@ config: LoadBalancingConfig,
   if (typeName in registeredLoadBalancerTypes) {
-    return new registeredLoadBalancerTypes[typeName].LoadBalancer(channelControlHelper);
+    return new registeredLoadBalancerTypes[typeName].LoadBalancer(
+      channelControlHelper
+    );
   } else {
@@ -149,6 +179,9 @@ return null;
 
-export function getFirstUsableConfig(configs: LoadBalancingConfig[], defaultPickFirst?: true): LoadBalancingConfig;
 export function getFirstUsableConfig(
   configs: LoadBalancingConfig[],
-  defaultPickFirst: boolean = false
+  fallbackTodefault?: true
+): LoadBalancingConfig;
+export function getFirstUsableConfig(
+  configs: LoadBalancingConfig[],
+  fallbackTodefault = false
 ): LoadBalancingConfig | null {
@@ -160,4 +193,10 @@ for (const config of configs) {
   }
-  if (defaultPickFirst) {
-    return new load_balancer_pick_first.PickFirstLoadBalancingConfig()
+  if (fallbackTodefault) {
+    if (defaultLoadBalancerType) {
+      return new registeredLoadBalancerTypes[
+        defaultLoadBalancerType
+      ]!.LoadBalancingConfig();
+    } else {
+      return null;
+    }
   } else {
@@ -168,4 +207,5 @@ return null;
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
 export function validateLoadBalancingConfig(obj: any): LoadBalancingConfig {
-  if (!(obj !== null  && (typeof obj === 'object'))) {
+  if (!(obj !== null && typeof obj === 'object')) {
     throw new Error('Load balancing config must be an object');
@@ -175,7 +215,11 @@ }
   if (keys.length !== 1) {
-    throw new Error('Provided load balancing config has multiple conflicting entries');
+    throw new Error(
+      'Provided load balancing config has multiple conflicting entries'
+    );
   }
   const typeName = keys[0];
   if (typeName in registeredLoadBalancerTypes) {
-    return registeredLoadBalancerTypes[typeName].LoadBalancingConfig.createFromJson(obj[typeName]);
+    return registeredLoadBalancerTypes[
+      typeName
+    ].LoadBalancingConfig.createFromJson(obj[typeName]);
   } else {
@@ -185,6 +229,1 @@ throw new Error(`Unrecognized load balancing config name ${typeName}`);
 }
-
-export function registerAll() {
-  load_balancer_pick_first.setup();
-  load_balancer_round_robin.setup();
-}

src/logging.ts

@@ -20,6 +20,19 @@ /*
 
-let _logger: Partial<Console> = console;
+const DEFAULT_LOGGER: Partial<Console> = {
+  error: (message?: any, ...optionalParams: any[]) => {
+    console.error('E ' + message, ...optionalParams);
+  },
+  info: (message?: any, ...optionalParams: any[]) => {
+    console.error('I ' + message, ...optionalParams);
+  },
+  debug: (message?: any, ...optionalParams: any[]) => {
+    console.error('D ' + message, ...optionalParams);
+  },
+}
+
+let _logger: Partial<Console> = DEFAULT_LOGGER;
 let _logVerbosity: LogVerbosity = LogVerbosity.ERROR;
 
-const verbosityString = process.env.GRPC_NODE_VERBOSITY ?? process.env.GRPC_VERBOSITY ?? '';
+const verbosityString =
+  process.env.GRPC_NODE_VERBOSITY ?? process.env.GRPC_VERBOSITY ?? '';
 
@@ -57,8 +70,28 @@ switch (verbosityString.toUpperCase()) {
 export const log = (severity: LogVerbosity, ...args: any[]): void => {
-  if (severity >= _logVerbosity && typeof _logger.error === 'function') {
-    _logger.error(...args);
+  let logFunction: typeof DEFAULT_LOGGER.error;
+  if (severity >= _logVerbosity) {
+    switch (severity) {
+      case LogVerbosity.DEBUG:
+        logFunction = _logger.debug;
+        break;
+      case LogVerbosity.INFO:
+        logFunction = _logger.info;
+        break;
+      case LogVerbosity.ERROR:
+        logFunction = _logger.error;
+        break;
+    }
+    /* Fall back to _logger.error when other methods are not available for
+     * compatiblity with older behavior that always logged to _logger.error */
+    if (!logFunction) {
+      logFunction = _logger.error;
+    }
+    if (logFunction) {
+      logFunction.bind(_logger)(...args);
+    }
   }
 };
 
-const tracersString = process.env.GRPC_NODE_TRACE ?? process.env.GRPC_TRACE ?? '';
+const tracersString =
+  process.env.GRPC_NODE_TRACE ?? process.env.GRPC_TRACE ?? '';
 const enabledTracers = new Set<string>();
@@ -70,3 +103,3 @@ const disabledTracers = new Set<string>();
   } else {
-    enabledTracers.add(tracerName)
+    enabledTracers.add(tracerName);
   }
@@ -81,5 +114,8 @@ }
 ): void {
-  if (!disabledTracers.has(tracer) && (allEnabled || enabledTracers.has(tracer))) {
+  if (
+    !disabledTracers.has(tracer) &&
+    (allEnabled || enabledTracers.has(tracer))
+  ) {
     log(severity, new Date().toISOString() + ' | ' + tracer + ' | ' + text);
   }
 }

src/make-client.ts

@@ -101,3 +101,3 @@ /*
  */
-function isPrototypePolluted(key: string): Boolean {
+function isPrototypePolluted(key: string): boolean {
   return ['__proto__', 'prototype', 'constructor'].includes(key);
@@ -104,0 +104,0 @@ }

src/max-message-size-filter.ts

@@ -18,6 +18,10 @@ /*
 
-import { BaseFilter, Filter, FilterFactory } from "./filter";
-import { Call, WriteObject } from "./call-stream";
-import { Status, DEFAULT_MAX_SEND_MESSAGE_LENGTH, DEFAULT_MAX_RECEIVE_MESSAGE_LENGTH } from "./constants";
-import { ChannelOptions } from "./channel-options";
+import { BaseFilter, Filter, FilterFactory } from './filter';
+import { Call, WriteObject } from './call-stream';
+import {
+  Status,
+  DEFAULT_MAX_SEND_MESSAGE_LENGTH,
+  DEFAULT_MAX_RECEIVE_MESSAGE_LENGTH,
+} from './constants';
+import { ChannelOptions } from './channel-options';
 
@@ -48,3 +52,6 @@ export class MaxMessageSizeFilter extends BaseFilter implements Filter {
       if (concreteMessage.message.length > this.maxSendMessageSize) {
-        this.callStream.cancelWithStatus(Status.RESOURCE_EXHAUSTED, `Sent message larger than max (${concreteMessage.message.length} vs. ${this.maxSendMessageSize})`);
+        this.callStream.cancelWithStatus(
+          Status.RESOURCE_EXHAUSTED,
+          `Sent message larger than max (${concreteMessage.message.length} vs. ${this.maxSendMessageSize})`
+        );
         return Promise.reject<WriteObject>('Message too large');
@@ -65,3 +72,6 @@ } else {
       if (concreteMessage.length > this.maxReceiveMessageSize) {
-        this.callStream.cancelWithStatus(Status.RESOURCE_EXHAUSTED, `Received message larger than max (${concreteMessage.length} vs. ${this.maxReceiveMessageSize})`);
+        this.callStream.cancelWithStatus(
+          Status.RESOURCE_EXHAUSTED,
+          `Received message larger than max (${concreteMessage.length} vs. ${this.maxReceiveMessageSize})`
+        );
         return Promise.reject<Buffer>('Message too large');
@@ -75,3 +85,4 @@ } else {
 
-export class MaxMessageSizeFilterFactory implements FilterFactory<MaxMessageSizeFilter> {
+export class MaxMessageSizeFilterFactory
+  implements FilterFactory<MaxMessageSizeFilter> {
   constructor(private readonly options: ChannelOptions) {}
@@ -78,0 +89,0 @@

src/metadata.ts

@@ -246,2 +246,14 @@ /*
   /**
+   * This modifies the behavior of JSON.stringify to show an object
+   * representation of the metadata map.
+   */
+  toJSON() {
+    const result: { [key: string]: MetadataValue[] } = {};
+    for (const [key, values] of this.internalRepr.entries()) {
+      result[key] = values;
+    }
+    return result;
+  }
+
+  /**
    * Returns a new Metadata object based fields in a given IncomingHttpHeaders
@@ -248,0 +260,0 @@ * object.

src/picker.ts

@@ -50,3 +50,3 @@ /*
    */
-  extraFilterFactory: FilterFactory<Filter> | null;
+  extraFilterFactories: FilterFactory<Filter>[];
   onCallStarted: (() => void) | null;
@@ -59,3 +59,3 @@ }
   status: null;
-  extraFilterFactory: FilterFactory<Filter> | null;
+  extraFilterFactories: FilterFactory<Filter>[];
   onCallStarted: (() => void) | null;
@@ -68,3 +68,3 @@ }
   status: null;
-  extraFilterFactory: null;
+  extraFilterFactories: [];
   onCallStarted: null;
@@ -77,3 +77,3 @@ }
   status: StatusObject;
-  extraFilterFactory: null;
+  extraFilterFactories: [];
   onCallStarted: null;
@@ -86,3 +86,3 @@ }
   status: StatusObject;
-  extraFilterFactory: null;
+  extraFilterFactories: [];
   onCallStarted: null;
@@ -93,3 +93,3 @@ }
   metadata: Metadata;
-  extraPickInfo: {[key: string]: string};
+  extraPickInfo: { [key: string]: string };
 }
@@ -128,3 +128,3 @@
       status: this.status,
-      extraFilterFactory: null,
+      extraFilterFactories: [],
       onCallStarted: null,
@@ -158,3 +158,3 @@ };
       status: null,
-      extraFilterFactory: null,
+      extraFilterFactories: [],
       onCallStarted: null,
@@ -161,0 +161,0 @@ };

src/resolver-dns.ts

@@ -31,3 +31,3 @@ /*
 import { LogVerbosity } from './constants';
-import { SubchannelAddress, TcpSubchannelAddress } from './subchannel';
+import { SubchannelAddress, TcpSubchannelAddress } from './subchannel-address';
 import { GrpcUri, uriToString, splitHostPort } from './uri-parser';
@@ -133,3 +133,9 @@ import { isIPv6, isIPv4 } from 'net';
       setImmediate(() => {
-        this.listener.onSuccessfulResolution(this.ipResult!, null, null, null, {});
+        this.listener.onSuccessfulResolution(
+          this.ipResult!,
+          null,
+          null,
+          null,
+          {}
+        );
       });
@@ -136,0 +142,0 @@ return;

src/resolver-ip.ts

@@ -17,10 +17,10 @@ /*
 
-import { isIPv4, isIPv6 } from "net";
-import { StatusObject } from "./call-stream";
-import { ChannelOptions } from "./channel-options";
-import { LogVerbosity, Status } from "./constants";
-import { Metadata } from "./metadata";
-import { registerResolver, Resolver, ResolverListener } from "./resolver";
-import { SubchannelAddress } from "./subchannel";
-import { GrpcUri, splitHostPort, uriToString } from "./uri-parser";
+import { isIPv4, isIPv6 } from 'net';
+import { StatusObject } from './call-stream';
+import { ChannelOptions } from './channel-options';
+import { LogVerbosity, Status } from './constants';
+import { Metadata } from './metadata';
+import { registerResolver, Resolver, ResolverListener } from './resolver';
+import { SubchannelAddress } from './subchannel-address';
+import { GrpcUri, splitHostPort, uriToString } from './uri-parser';
 import * as logging from './logging';
@@ -56,3 +56,3 @@
         details: `Unrecognized scheme ${target.scheme} in IP resolver`,
-        metadata: new Metadata()
+        metadata: new Metadata(),
       };
@@ -68,11 +68,14 @@ return;
           details: `Failed to parse ${target.scheme} address ${path}`,
-          metadata: new Metadata()
+          metadata: new Metadata(),
         };
         return;
       }
-      if ((target.scheme === IPV4_SCHEME && !isIPv4(hostPort.host)) || (target.scheme === IPV6_SCHEME && !isIPv6(hostPort.host))) {
+      if (
+        (target.scheme === IPV4_SCHEME && !isIPv4(hostPort.host)) ||
+        (target.scheme === IPV6_SCHEME && !isIPv6(hostPort.host))
+      ) {
         this.error = {
           code: Status.UNAVAILABLE,
           details: `Failed to parse ${target.scheme} address ${path}`,
-          metadata: new Metadata()
+          metadata: new Metadata(),
         };
@@ -83,3 +86,3 @@ return;
         host: hostPort.host,
-        port: hostPort.port ?? DEFAULT_PORT
+        port: hostPort.port ?? DEFAULT_PORT,
       });
@@ -93,5 +96,11 @@ }
       if (this.error) {
-        this.listener.onError(this.error)
+        this.listener.onError(this.error);
       } else {
-        this.listener.onSuccessfulResolution(this.addresses, null, null, null, {});
+        this.listener.onSuccessfulResolution(
+          this.addresses,
+          null,
+          null,
+          null,
+          {}
+        );
       }
@@ -112,2 +121,2 @@ });
   registerResolver(IPV6_SCHEME, IpResolver);
-}
+}

src/resolver-uds.ts

@@ -18,3 +18,3 @@ /*
 import { Resolver, ResolverListener, registerResolver } from './resolver';
-import { SubchannelAddress } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 import { GrpcUri } from './uri-parser';
@@ -21,0 +21,0 @@ import { ChannelOptions } from './channel-options';

src/resolver.ts

@@ -19,7 +19,4 @@ /*
 import { MethodConfig, ServiceConfig } from './service-config';
-import * as resolver_dns from './resolver-dns';
-import * as resolver_uds from './resolver-uds';
-import * as resolver_ip from './resolver-ip';
 import { StatusObject } from './call-stream';
-import { SubchannelAddress } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 import { GrpcUri, uriToString } from './uri-parser';
@@ -29,2 +26,3 @@ import { ChannelOptions } from './channel-options';
 import { Status } from './constants';
+import { Filter, FilterFactory } from './filter';
 
@@ -34,4 +32,5 @@ export interface CallConfig {
   onCommitted?: () => void;
-  pickInformation: {[key: string]: string};
+  pickInformation: { [key: string]: string };
   status: Status;
+  dynamicFilterFactories: FilterFactory<Filter>[];
 }
@@ -87,3 +86,3 @@
   updateResolution(): void;
-  
+
   /**
@@ -183,7 +182,1 @@ * Destroy the resolver. Should be called when the owning channel shuts down.
 }
-
-export function registerAll() {
-  resolver_dns.setup();
-  resolver_uds.setup();
-  resolver_ip.setup();
-}

src/resolving-load-balancer.ts

@@ -21,7 +21,7 @@ /*
   LoadBalancer,
+  LoadBalancingConfig,
   getFirstUsableConfig,
-  LoadBalancingConfig
 } from './load-balancer';
 import { ServiceConfig, validateServiceConfig } from './service-config';
-import { ConnectivityState } from './channel';
+import { ConnectivityState } from './connectivity-state';
 import { ConfigSelector, createResolver, Resolver } from './resolver';
@@ -36,3 +36,3 @@ import { ServiceError } from './call';
 import { LogVerbosity } from './constants';
-import { SubchannelAddress } from './subchannel';
+import { SubchannelAddress } from './subchannel-address';
 import { GrpcUri, uriToString } from './uri-parser';
@@ -51,5 +51,10 @@ import { ChildLoadBalancerHandler } from './load-balancer-child-handler';
 
-function getDefaultConfigSelector(serviceConfig: ServiceConfig | null): ConfigSelector {
-  return function defaultConfigSelector(methodName: string, metadata: Metadata) {
-    const splitName = methodName.split('/').filter(x => x.length > 0);
+function getDefaultConfigSelector(
+  serviceConfig: ServiceConfig | null
+): ConfigSelector {
+  return function defaultConfigSelector(
+    methodName: string,
+    metadata: Metadata
+  ) {
+    const splitName = methodName.split('/').filter((x) => x.length > 0);
     const service = splitName[0] ?? '';
@@ -60,7 +65,11 @@ const method = splitName[1] ?? '';
         for (const name of methodConfig.name) {
-          if (name.service === service && (name.method === undefined || name.method === method)) {
+          if (
+            name.service === service &&
+            (name.method === undefined || name.method === method)
+          ) {
             return {
               methodConfig: methodConfig,
               pickInformation: {},
-              status: Status.OK
+              status: Status.OK,
+              dynamicFilterFactories: []
             };
@@ -72,7 +81,8 @@ }
     return {
-      methodConfig: {name: []},
+      methodConfig: { name: [] },
       pickInformation: {},
-      status: Status.OK
+      status: Status.OK,
+      dynamicFilterFactories: []
     };
-  }
+  };
 }
@@ -170,2 +180,8 @@
       },
+      addChannelzChild: channelControlHelper.addChannelzChild.bind(
+        channelControlHelper
+      ),
+      removeChannelzChild: channelControlHelper.removeChannelzChild.bind(
+        channelControlHelper
+      )
     });
@@ -210,3 +226,6 @@ this.innerResolver = createResolver(
             workingServiceConfig?.loadBalancingConfig ?? [];
-          const loadBalancingConfig = getFirstUsableConfig(workingConfigList, true);
+          const loadBalancingConfig = getFirstUsableConfig(
+            workingConfigList,
+            true
+          );
           if (loadBalancingConfig === null) {
@@ -227,4 +246,7 @@ // There were load balancing configs but none are supported. This counts as a resolution failure
           );
-          const finalServiceConfig = workingServiceConfig ?? this.defaultServiceConfig;
-          this.onSuccessfulResolution(configSelector ?? getDefaultConfigSelector(finalServiceConfig));
+          const finalServiceConfig =
+            workingServiceConfig ?? this.defaultServiceConfig;
+          this.onSuccessfulResolution(
+            configSelector ?? getDefaultConfigSelector(finalServiceConfig)
+          );
         },
@@ -231,0 +253,0 @@ onError: (error: StatusObject) => {

src/server-call.ts

@@ -103,3 +103,4 @@ /*
 
-export class ServerUnaryCallImpl<RequestType, ResponseType> extends EventEmitter
+export class ServerUnaryCallImpl<RequestType, ResponseType>
+  extends EventEmitter
   implements ServerUnaryCall<RequestType, ResponseType> {
@@ -243,3 +244,4 @@ cancelled: boolean;
 
-export class ServerDuplexStreamImpl<RequestType, ResponseType> extends Duplex
+export class ServerDuplexStreamImpl<RequestType, ResponseType>
+  extends Duplex
   implements ServerDuplexStream<RequestType, ResponseType> {
@@ -414,2 +416,4 @@ cancelled: boolean;
       this.emit('cancelled', 'cancelled');
+      this.emit('streamEnd', false);
+      this.sendStatus({code: Status.CANCELLED, details: 'Cancelled by client', metadata: new Metadata()});
     });
@@ -517,2 +521,3 @@
 
+          this.emit('receiveMessage');
           resolve(this.deserializeMessage(requestBytes));
@@ -580,2 +585,4 @@ } catch (err) {
   sendStatus(statusObj: StatusObject) {
+    this.emit('callEnd', statusObj.code);
+    this.emit('streamEnd', statusObj.code === Status.OK);
     if (this.checkCancelled()) {
@@ -615,5 +622,2 @@ return;
   sendError(error: ServerErrorResponse | ServerStatusResponse) {
-    if (this.checkCancelled()) {
-      return;
-    }
     const status: StatusObject = {
@@ -660,2 +664,3 @@ code: Status.UNKNOWN,
     this.sendMetadata();
+    this.emit('sendMessage');
     return this.stream.write(chunk);
@@ -696,2 +701,3 @@ }
         }
+        this.emit('receiveMessage');
         this.pushOrBufferMessage(readable, message);
@@ -698,0 +704,0 @@ }

src/server.ts

@@ -59,11 +59,10 @@ /*
   subchannelAddressToString,
-} from './subchannel';
+  stringToSubchannelAddress,
+} from './subchannel-address';
 import { parseUri } from './uri-parser';
+import { ChannelzCallTracker, ChannelzChildrenTracker, ChannelzTrace, registerChannelzServer, registerChannelzSocket, ServerInfo, ServerRef, SocketInfo, SocketRef, TlsInfo, unregisterChannelzRef } from './channelz';
+import { CipherNameAndProtocol, TLSSocket } from 'tls';
 
 const TRACER_NAME = 'server';
 
-function trace(text: string): void {
-  logging.trace(LogVerbosity.DEBUG, TRACER_NAME, text);
-}
-
 interface BindResult {
@@ -129,4 +128,17 @@ port: number;
 
+interface ChannelzSessionInfo {
+  ref: SocketRef;
+  streamTracker: ChannelzCallTracker;
+  messagesSent: number;
+  messagesReceived: number;
+  lastMessageSentTimestamp: Date | null;
+  lastMessageReceivedTimestamp: Date | null;
+}
+
+interface ChannelzListenerInfo {
+  ref: SocketRef;
+}
+
 export class Server {
-  private http2ServerList: (http2.Http2Server | http2.Http2SecureServer)[] = [];
+  private http2ServerList: { server: (http2.Http2Server | http2.Http2SecureServer), channelzRef: SocketRef }[] = [];
 
@@ -137,10 +149,77 @@ private handlers: Map<string, UntypedHandler> = new Map<
   >();
-  private sessions = new Set<http2.ServerHttp2Session>();
+  private sessions = new Map<http2.ServerHttp2Session, ChannelzSessionInfo>();
   private started = false;
   private options: ChannelOptions;
 
+  // Channelz Info
+  private channelzRef: ServerRef;
+  private channelzTrace = new ChannelzTrace();
+  private callTracker = new ChannelzCallTracker();
+  private listenerChildrenTracker = new ChannelzChildrenTracker();
+  private sessionChildrenTracker = new ChannelzChildrenTracker();
+
   constructor(options?: ChannelOptions) {
     this.options = options ?? {};
+    this.channelzRef = registerChannelzServer(() => this.getChannelzInfo());
+    this.channelzTrace.addTrace('CT_INFO', 'Server created');
+    this.trace('Server constructed');
   }
 
+  private getChannelzInfo(): ServerInfo {
+    return {
+      trace: this.channelzTrace,
+      callTracker: this.callTracker,
+      listenerChildren: this.listenerChildrenTracker.getChildLists(),
+      sessionChildren: this.sessionChildrenTracker.getChildLists()
+    };
+  }
+
+  private getChannelzSessionInfoGetter(session: http2.ServerHttp2Session): () => SocketInfo {
+    return () => {
+      const sessionInfo = this.sessions.get(session)!;
+      const sessionSocket = session.socket;
+      const remoteAddress = sessionSocket.remoteAddress ? stringToSubchannelAddress(sessionSocket.remoteAddress, sessionSocket.remotePort) : null;
+      const localAddress = stringToSubchannelAddress(sessionSocket.localAddress, sessionSocket.localPort);
+      let tlsInfo: TlsInfo | null;
+      if (session.encrypted) {
+        const tlsSocket: TLSSocket = sessionSocket as TLSSocket;
+        const cipherInfo: CipherNameAndProtocol & {standardName?: string} = tlsSocket.getCipher();
+        const certificate = tlsSocket.getCertificate();
+        const peerCertificate = tlsSocket.getPeerCertificate();
+        tlsInfo = {
+          cipherSuiteStandardName: cipherInfo.standardName ?? null,
+          cipherSuiteOtherName: cipherInfo.standardName ? null : cipherInfo.name,
+          localCertificate: (certificate && 'raw' in certificate) ? certificate.raw : null,
+          remoteCertificate: (peerCertificate && 'raw' in peerCertificate) ? peerCertificate.raw : null
+        };
+      } else {
+        tlsInfo = null;
+      }
+      const socketInfo: SocketInfo = {
+        remoteAddress: remoteAddress,
+        localAddress: localAddress,
+        security: tlsInfo,
+        remoteName: null,
+        streamsStarted: sessionInfo.streamTracker.callsStarted,
+        streamsSucceeded: sessionInfo.streamTracker.callsSucceeded,
+        streamsFailed: sessionInfo.streamTracker.callsFailed,
+        messagesSent: sessionInfo.messagesSent,
+        messagesReceived: sessionInfo.messagesReceived,
+        keepAlivesSent: 0,
+        lastLocalStreamCreatedTimestamp: null,
+        lastRemoteStreamCreatedTimestamp: sessionInfo.streamTracker.lastCallStartedTimestamp,
+        lastMessageSentTimestamp: sessionInfo.lastMessageSentTimestamp,
+        lastMessageReceivedTimestamp: sessionInfo.lastMessageReceivedTimestamp,
+        localFlowControlWindow: session.state.localWindowSize ?? null,
+        remoteFlowControlWindow: session.state.remoteWindowSize ?? null
+      };
+      return socketInfo;
+    };
+  }
+
+  private trace(text: string): void {
+    logging.trace(LogVerbosity.DEBUG, TRACER_NAME, '(' + this.channelzRef.id + ') ' + text);
+  }
+  
+
   addProtoService(): void {
@@ -215,6 +294,3 @@ throw new Error('Not implemented. Use addService() instead');
   removeService(service: ServiceDefinition): void {
-    if (
-      service === null ||
-      typeof service !== 'object'
-    ) {
+    if (service === null || typeof service !== 'object') {
       throw new Error('removeService() requires object as argument');
@@ -247,4 +323,4 @@ }
 
-    if (creds === null || typeof creds !== 'object') {
-      throw new TypeError('creds must be an object');
+    if (creds === null || !(creds instanceof ServerCredentials)) {
+      throw new TypeError('creds must be a ServerCredentials object');
     }
@@ -266,6 +342,8 @@
     const serverOptions: http2.ServerOptions = {
-      maxSendHeaderBlockLength: Number.MAX_SAFE_INTEGER
+      maxSendHeaderBlockLength: Number.MAX_SAFE_INTEGER,
     };
     if ('grpc-node.max_session_memory' in this.options) {
-      serverOptions.maxSessionMemory = this.options['grpc-node.max_session_memory'];
+      serverOptions.maxSessionMemory = this.options[
+        'grpc-node.max_session_memory'
+      ];
     }
@@ -278,2 +356,6 @@ if ('grpc.max_concurrent_streams' in this.options) {
 
+    const deferredCallback = (error: Error | null, port: number) => {
+      process.nextTick(() => callback(error, port));
+    }
+
     const setupServer = (): http2.Http2Server | http2.Http2SecureServer => {
@@ -306,3 +388,3 @@ let http2Server: http2.Http2Server | http2.Http2SecureServer;
         addressList.map((address) => {
-          trace('Attempting to bind ' + subchannelAddressToString(address));
+          this.trace('Attempting to bind ' + subchannelAddressToString(address));
           let addr: SubchannelAddress;
@@ -320,3 +402,4 @@ if (isTcpSubchannelAddress(address)) {
           return new Promise<number | Error>((resolve, reject) => {
-            function onError(err: Error): void {
+            const onError = (err: Error) => {
+              this.trace('Failed to bind ' + subchannelAddressToString(address) + ' with error ' + err.message);
               resolve(err);
@@ -328,10 +411,38 @@ }
             http2Server.listen(addr, () => {
-              trace('Successfully bound ' + subchannelAddressToString(address));
-              this.http2ServerList.push(http2Server);
               const boundAddress = http2Server.address()!;
+              let boundSubchannelAddress: SubchannelAddress;
               if (typeof boundAddress === 'string') {
-                resolve(portNum);
+                boundSubchannelAddress = {
+                  path: boundAddress
+                };
               } else {
-                resolve(boundAddress.port);
+                boundSubchannelAddress = {
+                  host: boundAddress.address,
+                  port: boundAddress.port
+                }
               }
+              const channelzRef = registerChannelzSocket(subchannelAddressToString(boundSubchannelAddress), () => {
+                return {
+                  localAddress: boundSubchannelAddress,
+                  remoteAddress: null,
+                  security: null,
+                  remoteName: null,
+                  streamsStarted: 0,
+                  streamsSucceeded: 0,
+                  streamsFailed: 0,
+                  messagesSent: 0,
+                  messagesReceived: 0,
+                  keepAlivesSent: 0,
+                  lastLocalStreamCreatedTimestamp: null,
+                  lastRemoteStreamCreatedTimestamp: null,
+                  lastMessageSentTimestamp: null,
+                  lastMessageReceivedTimestamp: null,
+                  localFlowControlWindow: null,
+                  remoteFlowControlWindow: null
+                };
+              });
+              this.listenerChildrenTracker.refChild(channelzRef);
+              this.http2ServerList.push({server: http2Server, channelzRef: channelzRef});
+              this.trace('Successfully bound ' + subchannelAddressToString(boundSubchannelAddress));
+              resolve('port' in boundSubchannelAddress ? boundSubchannelAddress.port : portNum);
               http2Server.removeListener('error', onError);
@@ -369,3 +480,4 @@ });
       return new Promise<BindResult>((resolve, reject) => {
-        function onError(err: Error): void {
+        const onError = (err: Error) => {
+          this.trace('Failed to bind ' + subchannelAddressToString(address) + ' with error ' + err.message);
           resolve(bindWildcardPort(addressList.slice(1)));
@@ -377,7 +489,34 @@ }
         http2Server.listen(address, () => {
-          this.http2ServerList.push(http2Server);
+          const boundAddress = http2Server.address() as AddressInfo;
+          const boundSubchannelAddress: SubchannelAddress = {
+            host: boundAddress.address,
+            port: boundAddress.port
+          };
+          const channelzRef = registerChannelzSocket(subchannelAddressToString(boundSubchannelAddress), () => {
+            return {
+              localAddress: boundSubchannelAddress,
+              remoteAddress: null,
+              security: null,
+              remoteName: null,
+              streamsStarted: 0,
+              streamsSucceeded: 0,
+              streamsFailed: 0,
+              messagesSent: 0,
+              messagesReceived: 0,
+              keepAlivesSent: 0,
+              lastLocalStreamCreatedTimestamp: null,
+              lastRemoteStreamCreatedTimestamp: null,
+              lastMessageSentTimestamp: null,
+              lastMessageReceivedTimestamp: null,
+              localFlowControlWindow: null,
+              remoteFlowControlWindow: null
+            };
+          });
+          this.listenerChildrenTracker.refChild(channelzRef);
+          this.http2ServerList.push({server: http2Server, channelzRef: channelzRef});
+          this.trace('Successfully bound ' + subchannelAddressToString(boundSubchannelAddress));
           resolve(
             bindSpecificPort(
               addressList.slice(1),
-              (http2Server.address() as AddressInfo).port,
+              boundAddress.port,
               1
@@ -400,3 +539,3 @@ )
         if (addressList.length === 0) {
-          callback(new Error(`No addresses resolved for port ${port}`), 0);
+          deferredCallback(new Error(`No addresses resolved for port ${port}`), 0);
           return;
@@ -424,3 +563,3 @@ }
               logging.log(LogVerbosity.ERROR, errorString);
-              callback(new Error(errorString), 0);
+              deferredCallback(new Error(errorString), 0);
             } else {
@@ -433,3 +572,3 @@ if (bindResult.count < addressList.length) {
               }
-              callback(null, bindResult.port);
+              deferredCallback(null, bindResult.port);
             }
@@ -440,3 +579,3 @@ },
             logging.log(LogVerbosity.ERROR, errorString);
-            callback(new Error(errorString), 0);
+            deferredCallback(new Error(errorString), 0);
           }
@@ -446,3 +585,3 @@ );
       onError: (error) => {
-        callback(new Error(error.details), 0);
+        deferredCallback(new Error(error.details), 0);
       },
@@ -458,5 +597,8 @@ };
 
-    for (const http2Server of this.http2ServerList) {
+    for (const {server: http2Server, channelzRef: ref} of this.http2ServerList) {
       if (http2Server.listening) {
-        http2Server.close();
+        http2Server.close(() => {
+          this.listenerChildrenTracker.unrefChild(ref);
+          unregisterChannelzRef(ref);
+        });
       }
@@ -469,3 +611,3 @@ }
     // tryShutdown() calls are in progress. Don't wait on them to finish.
-    this.sessions.forEach((session) => {
+    this.sessions.forEach((channelzInfo, session) => {
       // Cast NGHTTP2_CANCEL to any because TypeScript doesn't seem to
@@ -477,2 +619,3 @@ // recognize destroy(code) as a valid signature.
     this.sessions.clear();
+    unregisterChannelzRef(this.channelzRef);
   }
@@ -509,3 +652,3 @@
       this.http2ServerList.every(
-        (http2Server) => http2Server.listening !== true
+        ({server: http2Server}) => http2Server.listening !== true
       )
@@ -519,3 +662,3 @@ ) {
     }
-
+    this.channelzTrace.addTrace('CT_INFO', 'Starting');
     this.started = true;
@@ -525,2 +668,6 @@ }
   tryShutdown(callback: (error?: Error) => void): void {
+    const wrappedCallback = (error?: Error) => {
+      unregisterChannelzRef(this.channelzRef);
+      callback(error);
+    };
     let pendingChecks = 0;
@@ -532,3 +679,3 @@
       if (pendingChecks === 0) {
-        callback();
+        wrappedCallback();
       }
@@ -540,10 +687,14 @@ }
 
-    for (const http2Server of this.http2ServerList) {
+    for (const {server: http2Server, channelzRef: ref} of this.http2ServerList) {
       if (http2Server.listening) {
         pendingChecks++;
-        http2Server.close(maybeCallback);
+        http2Server.close(() => {
+          this.listenerChildrenTracker.unrefChild(ref);
+          unregisterChannelzRef(ref);
+          maybeCallback();
+        });
       }
     }
 
-    this.sessions.forEach((session) => {
+    this.sessions.forEach((channelzInfo, session) => {
       if (!session.closed) {
@@ -555,3 +706,3 @@ pendingChecks += 1;
     if (pendingChecks === 0) {
-      callback();
+      wrappedCallback();
     }
@@ -564,2 +715,6 @@ }
 
+  getChannelzRef() {
+    return this.channelzRef;
+  }
+
   private _setupHandlers(
@@ -575,2 +730,5 @@ http2Server: http2.Http2Server | http2.Http2SecureServer
       (stream: http2.ServerHttp2Stream, headers: http2.IncomingHttpHeaders) => {
+        const channelzSessionInfo = this.sessions.get(stream.session as http2.ServerHttp2Session);
+        this.callTracker.addCallStarted();
+        channelzSessionInfo?.streamTracker.addCallStarted();
         const contentType = headers[http2.constants.HTTP2_HEADER_CONTENT_TYPE];
@@ -589,5 +747,9 @@
           );
+          this.callTracker.addCallFailed();
+          channelzSessionInfo?.streamTracker.addCallFailed();
           return;
         }
 
+        let call: Http2ServerCallStream<any, any> | null = null;
+
         try {
@@ -605,3 +767,3 @@ const path = headers[http2.constants.HTTP2_HEADER_PATH] as string;
           }
-          trace(
+          this.trace(
             'Received call to method ' +
@@ -615,3 +777,3 @@ path +
           if (handler === undefined) {
-            trace(
+            this.trace(
               'No handler registered for method ' +
@@ -624,3 +786,27 @@ path +
 
-          const call = new Http2ServerCallStream(stream, handler, this.options);
+          call = new Http2ServerCallStream(stream, handler, this.options);
+          call.once('callEnd', (code: Status) => {
+            if (code === Status.OK) {
+              this.callTracker.addCallSucceeded();
+            } else {
+              this.callTracker.addCallFailed();
+            }
+          });
+          if (channelzSessionInfo) {
+            call.once('streamEnd', (success: boolean) => {
+              if (success) {
+                channelzSessionInfo.streamTracker.addCallSucceeded();
+              } else {
+                channelzSessionInfo.streamTracker.addCallFailed();
+              }
+            });
+            call.on('sendMessage', () => {
+              channelzSessionInfo.messagesSent += 1;
+              channelzSessionInfo.lastMessageSentTimestamp = new Date();
+            });
+            call.on('receiveMessage', () => {
+              channelzSessionInfo.messagesReceived += 1;
+              channelzSessionInfo.lastMessageReceivedTimestamp = new Date();
+            });
+          }
           const metadata: Metadata = call.receiveMetadata(headers) as Metadata;
@@ -656,3 +842,7 @@ switch (handler.type) {
         } catch (err) {
-          const call = new Http2ServerCallStream(stream, null!, this.options);
+          if (!call) {
+            call = new Http2ServerCallStream(stream, null!, this.options);
+            this.callTracker.addCallFailed();
+            channelzSessionInfo?.streamTracker.addCallFailed()
+          }
 
@@ -674,5 +864,21 @@ if (err.code === undefined) {
 
-      this.sessions.add(session);
+      const channelzRef = registerChannelzSocket(session.socket.remoteAddress ?? 'unknown', this.getChannelzSessionInfoGetter(session));
 
+      const channelzSessionInfo: ChannelzSessionInfo = {
+        ref: channelzRef,
+        streamTracker: new ChannelzCallTracker(),
+        messagesSent: 0,
+        messagesReceived: 0,
+        lastMessageSentTimestamp: null,
+        lastMessageReceivedTimestamp: null
+      };
+
+      this.sessions.set(session, channelzSessionInfo);
+      const clientAddress = session.socket.remoteAddress;
+      this.channelzTrace.addTrace('CT_INFO', 'Connection established by client ' + clientAddress);
+      this.sessionChildrenTracker.refChild(channelzRef);
       session.on('close', () => {
+        this.channelzTrace.addTrace('CT_INFO', 'Connection dropped by client ' + clientAddress);
+        this.sessionChildrenTracker.unrefChild(channelzRef);
+        unregisterChannelzRef(channelzRef);
         this.sessions.delete(session);
@@ -679,0 +885,0 @@ });

src/service-config.ts

@@ -30,3 +30,6 @@ /*
 import * as os from 'os';
-import { LoadBalancingConfig, validateLoadBalancingConfig } from './load-balancer';
+import {
+  LoadBalancingConfig,
+  validateLoadBalancingConfig,
+} from './load-balancer';
 
@@ -38,6 +41,11 @@ export interface MethodConfigName {
 
+export interface Duration {
+  seconds: number;
+  nanos: number;
+}
+
 export interface MethodConfig {
   name: MethodConfigName[];
   waitForReady?: boolean;
-  timeout?: string;
+  timeout?: Duration;
   maxRequestBytes?: number;
@@ -106,9 +114,30 @@ maxResponseBytes?: number;
   if ('timeout' in obj) {
-    if (
-      !(typeof obj.timeout === 'string') ||
-      !TIMEOUT_REGEX.test(obj.timeout)
+    if (typeof obj.timeout === 'object') {
+      if (
+        !('seconds' in obj.timeout) ||
+        !(typeof obj.timeout.seconds === 'number')
+      ) {
+        throw new Error('Invalid method config: invalid timeout.seconds');
+      }
+      if (
+        !('nanos' in obj.timeout) ||
+        !(typeof obj.timeout.nanos === 'number')
+      ) {
+        throw new Error('Invalid method config: invalid timeout.nanos');
+      }
+      result.timeout = obj.timeout;
+    } else if (
+      typeof obj.timeout === 'string' &&
+      TIMEOUT_REGEX.test(obj.timeout)
     ) {
+      const timeoutParts = obj.timeout
+        .substring(0, obj.timeout.length - 1)
+        .split('.');
+      result.timeout = {
+        seconds: timeoutParts[0] | 0,
+        nanos: (timeoutParts[1] ?? 0) | 0,
+      };
+    } else {
       throw new Error('Invalid method config: invalid timeout');
     }
-    result.timeout = obj.timeout;
   }
@@ -115,0 +144,0 @@ if ('maxRequestBytes' in obj) {

src/subchannel-pool.ts

@@ -19,7 +19,7 @@ /*
 import { ChannelOptions, channelOptionsEqual } from './channel-options';
+import { Subchannel } from './subchannel';
 import {
-  Subchannel,
   SubchannelAddress,
   subchannelAddressEqual,
-} from './subchannel';
+} from './subchannel-address';
 import { ChannelCredentials } from './channel-credentials';
@@ -26,0 +26,0 @@ import { GrpcUri, uriToString } from './uri-parser';

src/subchannel.ts

@@ -21,10 +21,10 @@ /*
 import { Metadata } from './metadata';
-import { Http2CallStream } from './call-stream';
+import { Call, Http2CallStream, WriteObject } from './call-stream';
 import { ChannelOptions } from './channel-options';
-import { PeerCertificate, checkServerIdentity } from 'tls';
-import { ConnectivityState } from './channel';
+import { PeerCertificate, checkServerIdentity, TLSSocket, CipherNameAndProtocol } from 'tls';
+import { ConnectivityState } from './connectivity-state';
 import { BackoffTimeout, BackoffOptions } from './backoff-timeout';
 import { getDefaultAuthority } from './resolver';
 import * as logging from './logging';
-import { LogVerbosity } from './constants';
+import { LogVerbosity, Status } from './constants';
 import { getProxiedConnection, ProxyConnectionResult } from './http_proxy';
@@ -34,3 +34,9 @@ import * as net from 'net';
 import { ConnectionOptions } from 'tls';
-import { FilterFactory, Filter } from './filter';
+import { FilterFactory, Filter, BaseFilter } from './filter';
+import {
+  stringToSubchannelAddress,
+  SubchannelAddress,
+  subchannelAddressToString,
+} from './subchannel-address';
+import { SubchannelRef, ChannelzTrace, ChannelzChildrenTracker, SubchannelInfo, registerChannelzSubchannel, ChannelzCallTracker, SocketInfo, SocketRef, unregisterChannelzRef, registerChannelzSocket, TlsInfo } from './channelz';
 
@@ -41,10 +47,2 @@ const clientVersion = require('../../package.json').version;
 
-function trace(text: string): void {
-  logging.trace(LogVerbosity.DEBUG, TRACER_NAME, text);
-}
-
-function refTrace(text: string): void {
-  logging.trace(LogVerbosity.DEBUG, 'subchannel_refcount', text);
-}
-
 const MIN_CONNECT_TIMEOUT_MS = 20000;
@@ -68,2 +66,7 @@ const INITIAL_BACKOFF_MS = 1000;
 
+export interface SubchannelCallStatsTracker {
+  addMessageSent(): void;
+  addMessageReceived(): void;
+}
+
 const {
@@ -89,48 +92,2 @@ HTTP2_HEADER_AUTHORITY,
 
-export interface TcpSubchannelAddress {
-  port: number;
-  host: string;
-}
-
-export interface IpcSubchannelAddress {
-  path: string;
-}
-
-/**
- * This represents a single backend address to connect to. This interface is a
- * subset of net.SocketConnectOpts, i.e. the options described at
- * https://nodejs.org/api/net.html#net_socket_connect_options_connectlistener.
- * Those are in turn a subset of the options that can be passed to http2.connect.
- */
-export type SubchannelAddress = TcpSubchannelAddress | IpcSubchannelAddress;
-
-export function isTcpSubchannelAddress(
-  address: SubchannelAddress
-): address is TcpSubchannelAddress {
-  return 'port' in address;
-}
-
-export function subchannelAddressEqual(
-  address1: SubchannelAddress,
-  address2: SubchannelAddress
-): boolean {
-  if (isTcpSubchannelAddress(address1)) {
-    return (
-      isTcpSubchannelAddress(address2) &&
-      address1.host === address2.host &&
-      address1.port === address2.port
-    );
-  } else {
-    return !isTcpSubchannelAddress(address2) && address1.path === address2.path;
-  }
-}
-
-export function subchannelAddressToString(address: SubchannelAddress): string {
-  if (isTcpSubchannelAddress(address)) {
-    return address.host + ':' + address.port;
-  } else {
-    return address.path;
-  }
-}
-
 export class Subchannel {
@@ -191,3 +148,3 @@ /**
    */
-  private keepaliveWithoutCalls: boolean = false;
+  private keepaliveWithoutCalls = false;
 
@@ -208,3 +165,23 @@ /**
 
+  // Channelz info
+  private channelzRef: SubchannelRef;
+  private channelzTrace: ChannelzTrace;
+  private callTracker = new ChannelzCallTracker();
+  private childrenTracker = new ChannelzChildrenTracker();
+
+  // Channelz socket info
+  private channelzSocketRef: SocketRef | null = null;
   /**
+   * Name of the remote server, if it is not the same as the subchannel
+   * address, i.e. if connecting through an HTTP CONNECT proxy.
+   */
+  private remoteName: string | null = null;
+  private streamTracker = new ChannelzCallTracker();
+  private keepalivesSent = 0;
+  private messagesSent = 0;
+  private messagesReceived = 0;
+  private lastMessageSentTimestamp: Date | null = null;
+  private lastMessageReceivedTimestamp: Date | null = null;
+
+  /**
    * A class representing a connection to a single backend.
@@ -241,3 +218,4 @@ * @param channelTarget The target string for the channel as a whole
     if ('grpc.keepalive_permit_without_calls' in options) {
-      this.keepaliveWithoutCalls = options['grpc.keepalive_permit_without_calls'] === 1;
+      this.keepaliveWithoutCalls =
+        options['grpc.keepalive_permit_without_calls'] === 1;
     } else {
@@ -258,5 +236,85 @@ this.keepaliveWithoutCalls = false;
     this.subchannelAddressString = subchannelAddressToString(subchannelAddress);
-    trace('Subchannel constructed with options ' + JSON.stringify(options, undefined, 2));
+
+    this.channelzRef = registerChannelzSubchannel(this.subchannelAddressString, () => this.getChannelzInfo());
+    this.channelzTrace = new ChannelzTrace();
+    this.channelzTrace.addTrace('CT_INFO', 'Subchannel created');
+    this.trace('Subchannel constructed with options ' + JSON.stringify(options, undefined, 2));
   }
 
+  private getChannelzInfo(): SubchannelInfo {
+    return {
+      state: this.connectivityState,
+      trace: this.channelzTrace,
+      callTracker: this.callTracker,
+      children: this.childrenTracker.getChildLists(),
+      target: this.subchannelAddressString
+    };
+  }
+
+  private getChannelzSocketInfo(): SocketInfo | null {
+    if (this.session === null) {
+      return null;
+    }
+    const sessionSocket = this.session.socket;
+    const remoteAddress = sessionSocket.remoteAddress ? stringToSubchannelAddress(sessionSocket.remoteAddress, sessionSocket.remotePort) : null;
+    const localAddress = stringToSubchannelAddress(sessionSocket.localAddress, sessionSocket.localPort);
+    let tlsInfo: TlsInfo | null;
+    if (this.session.encrypted) {
+      const tlsSocket: TLSSocket = sessionSocket as TLSSocket;
+      const cipherInfo: CipherNameAndProtocol & {standardName?: string} = tlsSocket.getCipher();
+      const certificate = tlsSocket.getCertificate();
+      const peerCertificate = tlsSocket.getPeerCertificate();
+      tlsInfo = {
+        cipherSuiteStandardName: cipherInfo.standardName ?? null,
+        cipherSuiteOtherName: cipherInfo.standardName ? null : cipherInfo.name,
+        localCertificate: (certificate && 'raw' in certificate) ? certificate.raw : null,
+        remoteCertificate: (peerCertificate && 'raw' in peerCertificate) ? peerCertificate.raw : null
+      };
+    } else {
+      tlsInfo = null;
+    }
+    const socketInfo: SocketInfo = {
+      remoteAddress: remoteAddress,
+      localAddress: localAddress,
+      security: tlsInfo,
+      remoteName: this.remoteName,
+      streamsStarted: this.streamTracker.callsStarted,
+      streamsSucceeded: this.streamTracker.callsSucceeded,
+      streamsFailed: this.streamTracker.callsFailed,
+      messagesSent: this.messagesSent,
+      messagesReceived: this.messagesReceived,
+      keepAlivesSent: this.keepalivesSent,
+      lastLocalStreamCreatedTimestamp: this.streamTracker.lastCallStartedTimestamp,
+      lastRemoteStreamCreatedTimestamp: null,
+      lastMessageSentTimestamp: this.lastMessageSentTimestamp,
+      lastMessageReceivedTimestamp: this.lastMessageReceivedTimestamp,
+      localFlowControlWindow: this.session.state.localWindowSize ?? null,
+      remoteFlowControlWindow: this.session.state.remoteWindowSize ?? null
+    };
+    return socketInfo;
+  }
+
+  private resetChannelzSocketInfo() {
+    if (this.channelzSocketRef) {
+      unregisterChannelzRef(this.channelzSocketRef);
+      this.childrenTracker.unrefChild(this.channelzSocketRef);
+      this.channelzSocketRef = null;
+    }
+    this.remoteName = null;
+    this.streamTracker = new ChannelzCallTracker();
+    this.keepalivesSent = 0;
+    this.messagesSent = 0;
+    this.messagesReceived = 0;
+    this.lastMessageSentTimestamp = null;
+    this.lastMessageReceivedTimestamp = null;
+  }
+
+  private trace(text: string): void {
+    logging.trace(LogVerbosity.DEBUG, TRACER_NAME, '(' + this.channelzRef.id + ') ' + this.subchannelAddressString + ' ' + text);
+  }
+
+  private refTrace(text: string): void {
+    logging.trace(LogVerbosity.DEBUG, 'subchannel_refcount', '(' + this.channelzRef.id + ') ' + this.subchannelAddressString + ' ' + text);
+  }
+
   private handleBackoffTimer() {
@@ -289,3 +347,9 @@ if (this.continueConnecting) {
   private sendPing() {
-    logging.trace(LogVerbosity.DEBUG, 'keepalive', 'Sending ping to ' + this.subchannelAddressString);
+    this.keepalivesSent += 1;
+    logging.trace(
+      LogVerbosity.DEBUG,
+      'keepalive',
+      '(' + this.channelzRef.id + ') ' + this.subchannelAddressString + ' ' +
+      'Sending ping'
+    );
     this.keepaliveTimeoutId = setTimeout(() => {
@@ -306,3 +370,3 @@ this.transitionToState([ConnectivityState.READY], ConnectivityState.IDLE);
     }, this.keepaliveTimeMs);
-    this.keepaliveIntervalId.unref?.()
+    this.keepaliveIntervalId.unref?.();
     /* Don't send a ping immediately because whatever caused us to start
@@ -319,5 +383,7 @@ * sending pings should also involve some network activity. */
     if (proxyConnectionResult.realTarget) {
-      trace(this.subchannelAddressString + ' creating HTTP/2 session through proxy to ' + proxyConnectionResult.realTarget);
+      this.remoteName = uriToString(proxyConnectionResult.realTarget);
+      this.trace('creating HTTP/2 session through proxy to ' + proxyConnectionResult.realTarget);
     } else {
-      trace(this.subchannelAddressString + ' creating HTTP/2 session');
+      this.remoteName = null;
+      this.trace('creating HTTP/2 session');
     }
@@ -331,3 +397,5 @@ const targetAuthority = getDefaultAuthority(
     if ('grpc-node.max_session_memory' in this.options) {
-      connectionOptions.maxSessionMemory = this.options['grpc-node.max_session_memory'];
+      connectionOptions.maxSessionMemory = this.options[
+        'grpc-node.max_session_memory'
+      ];
     }
@@ -410,2 +478,4 @@ let addressScheme = 'http://';
     this.session = session;
+    this.channelzSocketRef = registerChannelzSocket(this.subchannelAddressString, () => this.getChannelzSocketInfo()!);
+    this.childrenTracker.refChild(this.channelzSocketRef);
     session.unref();
@@ -426,3 +496,3 @@ /* For all of these events, check if the session at the time of the event
       if (this.session === session) {
-        trace(this.subchannelAddressString + ' connection closed');
+        this.trace('connection closed');
         this.transitionToState(
@@ -457,8 +527,11 @@ [ConnectivityState.CONNECTING],
               LogVerbosity.ERROR,
-              `Connection to ${uriToString(this.channelTarget)} at ${this.subchannelAddressString} rejected by server because of excess pings. Increasing ping interval to ${this.keepaliveTimeMs} ms`
+              `Connection to ${uriToString(this.channelTarget)} at ${
+                this.subchannelAddressString
+              } rejected by server because of excess pings. Increasing ping interval to ${
+                this.keepaliveTimeMs
+              } ms`
             );
           }
-          trace(
-            this.subchannelAddressString +
-              ' connection closed by GOAWAY with code ' +
+          this.trace(
+            'connection closed by GOAWAY with code ' +
               errorCode
@@ -476,8 +549,8 @@ );
        * where we want to handle that.  */
-      trace(
-        this.subchannelAddressString +
-          ' connection closed with error ' +
+      this.trace(
+        'connection closed with error ' +
           (error as Error).message
       );
     });
+    registerChannelzSocket(this.subchannelAddressString, () => this.getChannelzSocketInfo()!);
   }
@@ -557,9 +630,8 @@
     }
-    trace(
-      this.subchannelAddressString +
-        ' ' +
-        ConnectivityState[this.connectivityState] +
+    this.trace(
+      ConnectivityState[this.connectivityState] +
         ' -> ' +
         ConnectivityState[newState]
     );
+    this.channelzTrace.addTrace('CT_INFO', ConnectivityState[this.connectivityState] + ' -> ' + ConnectivityState[newState]);
     const previousState = this.connectivityState;
@@ -589,2 +661,3 @@ this.connectivityState = newState;
         this.session = null;
+        this.resetChannelzSocketInfo();
         this.stopKeepalivePings();
@@ -605,2 +678,3 @@ /* If the backoff timer has already ended by the time we get to the
         this.session = null;
+        this.resetChannelzSocketInfo();
         this.stopKeepalivePings();
@@ -627,9 +701,8 @@ break;
     if (this.callRefcount === 0 && this.refcount === 0) {
+      this.channelzTrace.addTrace('CT_INFO', 'Shutting down');
       this.transitionToState(
-        [
-          ConnectivityState.CONNECTING,
-          ConnectivityState.READY,
-        ],
+        [ConnectivityState.CONNECTING, ConnectivityState.READY],
         ConnectivityState.TRANSIENT_FAILURE
       );
+      unregisterChannelzRef(this.channelzRef);
     }
@@ -639,5 +712,4 @@ }
   callRef() {
-    refTrace(
-      this.subchannelAddressString +
-        ' callRefcount ' +
+    this.refTrace(
+      'callRefcount ' +
         this.callRefcount +
@@ -660,5 +732,4 @@ ' -> ' +
   callUnref() {
-    refTrace(
-      this.subchannelAddressString +
-        ' callRefcount ' +
+    this.refTrace(
+      'callRefcount ' +
         this.callRefcount +
@@ -682,5 +753,4 @@ ' -> ' +
   ref() {
-    refTrace(
-      this.subchannelAddressString +
-        ' refcount ' +
+    this.refTrace(
+      'refcount ' +
         this.refcount +
@@ -694,5 +764,4 @@ ' -> ' +
   unref() {
-    refTrace(
-      this.subchannelAddressString +
-        ' refcount ' +
+    this.refTrace(
+      'refcount ' +
         this.refcount +
@@ -724,3 +793,3 @@ ' -> ' +
     callStream: Http2CallStream,
-    extraFilterFactory?: FilterFactory<Filter>
+    extraFilters: Filter[]
   ) {
@@ -756,4 +825,39 @@ const headers = metadata.toHttp2Headers();
     }
-    logging.trace(LogVerbosity.DEBUG, 'call_stream', 'Starting stream on subchannel ' + this.subchannelAddressString + ' with headers\n' + headersString);
-    callStream.attachHttp2Stream(http2Stream, this, extraFilterFactory);
+    logging.trace(
+      LogVerbosity.DEBUG,
+      'call_stream',
+      'Starting stream on subchannel ' +
+        '(' + this.channelzRef.id + ') ' +
+        this.subchannelAddressString +
+        ' with headers\n' +
+        headersString
+    );
+    this.callTracker.addCallStarted();
+    callStream.addStatusWatcher(status => {
+      if (status.code === Status.OK) {
+        this.callTracker.addCallSucceeded();
+      } else {
+        this.callTracker.addCallFailed();
+      }
+    });
+    const streamSession = this.session;
+    this.streamTracker.addCallStarted();
+    callStream.addStreamEndWatcher(success => {
+      if (streamSession === this.session) {
+        if (success) {
+          this.streamTracker.addCallSucceeded();
+        } else {
+          this.streamTracker.addCallFailed();
+        }
+      }
+    });
+    callStream.attachHttp2Stream(http2Stream, this, extraFilters, {
+      addMessageSent: () => {
+        this.messagesSent += 1;
+        this.lastMessageSentTimestamp = new Date();
+      },
+      addMessageReceived: () => {
+        this.messagesReceived += 1;
+      }
+    });
   }
@@ -837,2 +941,6 @@
   }
+
+  getChannelzRef(): SubchannelRef {
+    return this.channelzRef;
+  }
 }

New alerts

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Found 1 instance in 1 package

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Improved metrics

Total package byte prevSize

1205907

increased by17.83%

Number of package files

243

increased by27.23%

Lines of code

24880

increased by18.53%

Number of lines in readme file

48

increased by4.35%

Worsened metrics

Dependency count

2

increased by100%

Dependency changes

• + Added@grpc/proto-loader@^0.6.4

• + Added@grpc/proto-loader@0.6.13(transitive)

• + Added@protobufjs/aspromise@1.1.2(transitive)

• + Added@protobufjs/base64@1.1.2(transitive)

• + Added@protobufjs/codegen@2.0.4(transitive)

• + Added@protobufjs/eventemitter@1.1.0(transitive)

• + Added@protobufjs/fetch@1.1.0(transitive)

• + Added@protobufjs/float@1.0.2(transitive)

• + Added@protobufjs/inquire@1.1.0(transitive)

• + Added@protobufjs/path@1.1.2(transitive)

• + Added@protobufjs/pool@1.1.0(transitive)

• + Added@protobufjs/utf8@1.1.0(transitive)

• + Added@types/long@4.0.2(transitive)

• + Addedansi-regex@5.0.1(transitive)

• + Addedansi-styles@4.3.0(transitive)

• + Addedcliui@7.0.4(transitive)

• + Addedcolor-convert@2.0.1(transitive)

• + Addedcolor-name@1.1.4(transitive)

• + Addedemoji-regex@8.0.0(transitive)

• + Addedescalade@3.2.0(transitive)

• + Addedget-caller-file@2.0.5(transitive)

• + Addedis-fullwidth-code-point@3.0.0(transitive)

• + Addedlodash.camelcase@4.3.0(transitive)

• + Addedlong@4.0.0(transitive)

• + Addedprotobufjs@6.11.4(transitive)

• + Addedrequire-directory@2.1.1(transitive)

• + Addedstring-width@4.2.3(transitive)

• + Addedstrip-ansi@6.0.1(transitive)

• + Addedwrap-ansi@7.0.0(transitive)

• + Addedy18n@5.0.8(transitive)

• + Addedyargs@16.2.0(transitive)

• + Addedyargs-parser@20.2.9(transitive)