express-prom-bundle - npm Package Compare versions

Comparing version 4.1.0 to 4.2.0

package.json

 {
   "name": "express-prom-bundle",
-  "version": "4.1.0",
+  "version": "4.2.0",
   "description": "express middleware with popular prometheus metrics in one bundle",
@@ -14,3 +14,4 @@ "main": "src/index.js",
   "scripts": {
-    "test": "node_modules/jasme/run.js"
+    "test": "node_modules/jasme/run.js",
+    "coverage": "make coverage"
   },
@@ -17,0 +18,0 @@ "author": "Konstantin Pogorelov <[e-mail]>",

README.md

@@ -43,2 +43,24 @@ [![build status](https://travis-ci.org/jochen-schweizer/express-prom-bundle.png)](https://travis-ci.org/jochen-schweizer/express-prom-bundle) [![Coverage Status](https://coveralls.io/repos/github/jochen-schweizer/express-prom-bundle/badge.svg?branch=master)](https://coveralls.io/github/jochen-schweizer/express-prom-bundle?branch=master) [![license](https://img.shields.io/github/license/mashape/apistatus.svg?maxAge=2592000)](https://www.tldrlegal.com/l/mit) [![NPM version](https://badge.fury.io/js/express-prom-bundle.png)](http://badge.fury.io/js/express-prom-bundle)
 
+## Usage with Node Cluster
+``` javascript
+if (cluster.isMaster) {
+    const numCPUs = Math.max(2, os.cpus().length);
+    const workers: cluster.Worker[] = [];
+    for (let i=1; i < numCPUs; i++) {
+        const worker = forkWorker();
+        workers.push(worker);
+    }
+    const metricsApp = express();
+    metricsApp.use('/cluster_metrics', promBundle.clusterMetrics());
+    metricsApp.listen(9999);
+    console.log('metrics listening on 9999'); // call localhost:9999/cluster_metrics for aggregated metrics
+} else {
+    const app = express();
+    app.use(promBundle({includeMethod: true});
+    app.use('/api', require('./api'));
+    app.listen(3000);
+}
+```
+The code the master process runs will expose an API with a single endpoint `/cluster_metrics` which returns an aggregate of all metrics from all the workers.
+
 ## Options
@@ -174,2 +196,38 @@
 
+## using with cluster
+
+You'll need to use an additional **clusterMetrics()** middleware.
+
+In the example below the master process will expose an API with a single endpoint `/metrics`
+which returns an aggregate of all metrics from all the workers.
+
+``` javascript
+const cluster = require('cluster');
+const promBundle = require('./src/index');
+const numCPUs = Math.max(2, require('os').cpus().length);
+const express = require('express');
+
+if (cluster.isMaster) {
+    for (let i = 1; i < numCPUs; i++) {
+        cluster.fork();
+    }
+
+    const metricsApp = express();
+    metricsApp.use('/metrics', promBundle.clusterMetrics());
+    metricsApp.listen(9999);
+
+    console.log('cluster metrics listening on 9999');
+    console.log('call localhost:9999/metrics for aggregated metrics');
+} else {
+    const app = express();
+    app.use(promBundle({
+        autoregister: false, // disable /metrics for single workers
+        includeMethod: true
+    }));
+    app.use((req, res) => res.send(`hello from pid ${process.pid}\n`));
+    app.listen(3000);
+    console.log(`worker ${process.pid} listening on 3000`);
+}
+```
+
 ## using with kraken.js
@@ -176,0 +234,0 @@

src/index.js

@@ -41,2 +41,19 @@ 'use strict';
 
+function clusterMetrics() {
+    const aggregatorRegistry = new promClient.AggregatorRegistry();
+
+    const metricsMiddleware = function(req, res, next) {
+      aggregatorRegistry.clusterMetrics((err, clusterMetrics) => {
+        if (err) {
+            console.error(err);
+            return res.sendStatus(500);
+        }
+        res.set('Content-Type', aggregatorRegistry.contentType);
+        res.send(clusterMetrics);
+      });
+    };
+
+    return metricsMiddleware;
+}
+
 function main(opts) {
@@ -124,3 +141,3 @@ opts = Object.assign(
     if (opts.autoregister && path.match(/^\/metrics\/?$/)) {
-      return metricsMiddleware(req, res);
+        return metricsMiddleware(req, res);
     }
@@ -170,2 +187,3 @@
 main.normalizeStatusCode = normalizeStatusCode;
+main.clusterMetrics = clusterMetrics;
 module.exports = main;

No alert changes

Improved metrics

Total package byte prevSize

18635

increased by15.3%

Lines of code

193

increased by8.43%

Number of lines in readme file

272

increased by27.1%

No dependency changes