gcloud-tracer

gcloud-trace

Custom Google Cloud StackDriver tracing client w/out monkey patching

Installation

npm i --save gcloud-trace

Usage

Configure google trace options:

https://github.com/GoogleCloudPlatform/cloud-trace-nodejs https://github.com/GoogleCloudPlatform/cloud-trace-nodejs/blob/a1650a414c153f68f904909f3bba1d9ae73270da/config.js

const trace  = require('gcloud-trace')
// initialize trace w/ options
trace.init(opts)

Glossary

Each bar line in the chart below is a SpanData. The first bar is the RootSpanData. SpanData's have names and have labels (reference properties).

Custom trace RootSpanData

const trace  = require('gcloud-trace')
trace.init(opts)

const spanName = 'root trace span'
const spanData = trace.createRootSpanData(spanName, {
  // optional options:
  // parent trace span info
  traceId: 'continuingFromAnotherService',
  parentSpanId: 'continuingFromAnotherService',
  // or traceHeader - spanData.toHeader() will return a traceHeader string to trace across services
  traceHeader: 'traceId/parentSpanId;o=1',
  // remove frames from stack trace for span
  // like if you wrap this library w/ your own helper/util
  skipFrames: 1,
  // span kind: RPC_SERVER or RPC_CLIENT
  spanKind: 'RPC_SERVER'
})
// ... see span data usage below

Custom trace RootSpanData for a request

// spanName will be the url path
// parent span info (traceId and parentSpanId) are extracted from req.headers[trace.HEADER_NAME]
// request info labels are automatically added to the span
const spanData = trace.createReqRootSpanData(req, res, {
  // optional options:
  // remove frames from stack trace for span
  // like if you wrap this library w/ your own helper/util
  skipFrames: 1,
  // span kind: RPC_SERVER or RPC_CLIENT
  spanKind: 'RPC_SERVER'
})
// ... see span data usage below

SpanData methods

// add trace span labels
spanData.addLabels('foo', 'bar')
// add trace span properties
spanData.addLabels({
  foo: 'bar'
})
// end trace span time and report to stackdriver
spanData.close()

Create a child SpanData

const spanName = 'childSpanName'
spanData.createChildSpanData(spanName) // same optional opts..

Maintain trace across services

client.js

const trace = require('gcloud-trace')
trace.start()
//...
const traceHeader = spanData.toHeader()
const headers = {}
headers[trace.HEADER_NAME] = traceHeader
http.request({
  hostname: 'foo.foo',
  port: 80,
  path: '/bar',
  headers: headers
}).end()

server.js

const trace = require('gcloud-trace')
trace.start()

http.createServer(function (req, res) {
  const rootSpan = trace.createReqRootSpanData(req, res)
  const timeoutSpan = rootSpan.createChildSpanData('timeout')
  setTimeout(function () {
    timeoutSpan.end() // not required, will auto end with root span..
    res.writeHead(200)
    rootSpan.end() // not required, will auto-end w/ res
    res.end()
  }, 100)
}).listen(80)

Maintain trace non-http across services

client.js

//...
const traceHeader = spanData.toHeader()
rpc({
  operation: 'foo',
  traceHeader: traceHeader,
  payload: { bar: 'qux' }
}, cb)

server.js

const trace =
rpcServer(function (data) {
  const payload = data.payload
  const rootSpan = createRootSpan(data.operation, {
    traceHeader: data.traceHeader
  })
  // ...
})

License

MIT