Merge pull request #402 from vtex/feat/jaeger-prometheus-metrics

Add Jaeger Prometheus metrics

Author: tiagonapoli

CHANGELOG.md

@@ -7,6 +7,14 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+## [6.35.1] - 2020-07-22
+### Added
+- [metrics] Export jaeger metrics.
+
+### Fixed
+- [metrics] Typo on event listened to increment `runtime_http_aborted_requests_total`.
+- [tracing:entrypoint] Fix waiting for response stream to finish. 
+
 ## [6.35.0] - 2020-07-08
 ### Added
 - [metrics] Create new Prometheus exported metrics:

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@vtex/api",
-  "version": "6.35.0",
+  "version": "6.35.1",
   "description": "VTEX I/O API client",
   "main": "lib/index.js",
   "typings": "lib/index.d.ts",

src/service/tracing/TracerSingleton.ts

@@ -1,5 +1,6 @@
-import { initTracer as initJaegerTracer, TracingConfig, TracingOptions } from 'jaeger-client'
+import { initTracer as initJaegerTracer, PrometheusMetricsFactory, TracingConfig, TracingOptions } from 'jaeger-client'
 import { Tracer } from 'opentracing'
+import promClient from 'prom-client'
 import { APP, LINKED, NODE_ENV, NODE_VTEX_API_VERSION, PRODUCTION, REGION, WORKSPACE } from '../../constants'
 import { AppTags } from '../../tracing/Tags'
 import { appIdToAppAtMajor } from '../../utils'
@@ -42,6 +43,13 @@ export class TracerSingleton {
     }
 
     const options: TracingOptions = {
+      /**
+       * Jaeger metric names are available in:
+       * https://github.com/jaegertracing/jaeger-client-node/blob/master/src/metrics/metrics.js
+       *
+       * Runtime will prefix these metrics with 'runtime:'
+       */
+      metrics: new PrometheusMetricsFactory(promClient as any, 'runtime'),
       tags: defaultTags,
     }
 

src/service/tracing/tracingMiddlewares.ts

@@ -38,9 +38,20 @@ export const addTracingMiddleware = (tracer: Tracer) => {
     }
 
     const rootSpan = tracer.extract(FORMAT_HTTP_HEADERS, ctx.request.headers) as undefined | SpanContext
-    const currentSpan = tracer.startSpan('unknown-operation', { childOf: rootSpan })
+    const currentSpan = tracer.startSpan('unknown-operation', {
+      childOf: rootSpan,
+      tags: { [OpentracingTags.SPAN_KIND]: OpentracingTags.SPAN_KIND_RPC_SERVER },
+    })
+
+    const initialSamplingDecision = getTraceInfo(currentSpan).isSampled
+
     ctx.tracing = { currentSpan, tracer }
-    ctx.req.once('abort', () => abortedRequests.inc({ [MetricLabels.REQUEST_HANDLER]: (currentSpan as any).operationName as string }, 1))
+    ctx.req.once('aborted', () =>
+      abortedRequests.inc({ [MetricLabels.REQUEST_HANDLER]: (currentSpan as any).operationName as string }, 1)
+    )
+
+    let responseClosed = false
+    ctx.res.once('close', () => (responseClosed = true))
 
     try {
       await next()
@@ -66,8 +77,11 @@ export const addTracingMiddleware = (tracer: Tracer) => {
 
       const traceInfo = getTraceInfo(currentSpan)
       if (traceInfo.isSampled) {
+        if (!initialSamplingDecision) {
+          currentSpan.setTag(OpentracingTags.SPAN_KIND, OpentracingTags.SPAN_KIND_RPC_SERVER)
+        }
+
         currentSpan.addTags({
-          [OpentracingTags.SPAN_KIND]: OpentracingTags.SPAN_KIND_RPC_SERVER,
           [OpentracingTags.HTTP_URL]: ctx.request.href,
           [OpentracingTags.HTTP_METHOD]: ctx.request.method,
           [OpentracingTags.HTTP_STATUS_CODE]: ctx.response.status,
@@ -82,17 +96,23 @@ export const addTracingMiddleware = (tracer: Tracer) => {
         ctx.set(TRACE_ID_HEADER, traceInfo.traceId)
       }
 
-      onStreamFinished(ctx.res, () => {
+      const onResFinished = () => {
         requestTimings.observe(
           {
             [MetricLabels.REQUEST_HANDLER]: (currentSpan as any).operationName as string,
           },
           hrToMillisFloat(process.hrtime(start))
         )
+
         concurrentRequests.dec(1)
         currentSpan.finish()
-      })
+      }
 
+      if (responseClosed) {
+        onResFinished()
+      } else {
+        onStreamFinished(ctx.res, onResFinished)
+      }
     }
   }
 }