feat: process tags for client trace statistics (#7177)

Author: tlhunter

packages/dd-trace/src/encode/span-stats.js

@@ -95,7 +95,7 @@ class SpanStatsEncoder extends AgentEncoder {
   }
 
   _encode (bytes, stats) {
-    this._encodeMapPrefix(bytes, 8)
+    this._encodeMapPrefix(bytes, stats.ProcessTags ? 9 : 8)
 
     this._encodeString(bytes, 'Hostname')
     this._encodeString(bytes, stats.Hostname)
@@ -123,6 +123,11 @@ class SpanStatsEncoder extends AgentEncoder {
 
     this._encodeString(bytes, 'Sequence')
     this._encodeLong(bytes, stats.Sequence)
+
+    if (stats.ProcessTags) {
+      this._encodeString(bytes, 'ProcessTags')
+      this._encodeString(bytes, stats.ProcessTags)
+    }
   }
 }
 

packages/dd-trace/src/process-tags/index.js

@@ -66,8 +66,7 @@ module.exports.DYNAMIC_INSTRUMENTATION_FIELD_NAME = 'process_tags'
 module.exports.TELEMETRY_FIELD_NAME = 'process_tags'
 module.exports.REMOTE_CONFIG_FIELD_NAME = 'process_tags'
 module.exports.CRASH_TRACKING_FIELD_NAME = 'process_tags'
-
-// TODO: CLIENT_TRACE_STATISTICS_FIELD_NAME process_tags
+module.exports.CLIENT_TRACE_STATISTICS_FIELD_NAME = 'ProcessTags'
 
 /**
  * Sanitize a process tag value

packages/dd-trace/src/span_stats.js

@@ -1,6 +1,6 @@
 'use strict'
 
-const os = require('os')
+const os = require('node:os')
 const pkg = require('../../../package.json')
 
 const { LogCollapsingLowestDenseDDSketch } = require('../../../vendor/dist/@datadog/sketches-js')
@@ -13,6 +13,7 @@ const {
 } = require('../../../ext/tags')
 const { ORIGIN_KEY, TOP_LEVEL_KEY } = require('./constants')
 const { version } = require('./pkg')
+const processTags = require('./process-tags')
 
 const { SpanStatsExporter } = require('./exporters/span-stats')
 
@@ -176,7 +177,8 @@ class SpanStatsProcessor {
       Lang: 'javascript',
       TracerVersion: pkg.version,
       RuntimeID: this.tags['runtime-id'],
-      Sequence: ++this.sequence
+      Sequence: ++this.sequence,
+      ProcessTags: processTags.serialized
     })
   }
 

packages/dd-trace/test/encode/span-stats.spec.js

@@ -17,6 +17,7 @@ const {
   DEFAULT_SPAN_NAME,
   DEFAULT_SERVICE_NAME
 } = require('../../src/encode/tags-processors')
+const processTags = require('../../src/process-tags')
 
 describe('span-stats-encode', () => {
   let encoder
@@ -71,7 +72,8 @@ describe('span-stats-encode', () => {
       Lang: 'javascript',
       TracerVersion: '1.2.3',
       RuntimeID: 'some-runtime-id',
-      Sequence: 1
+      Sequence: 1,
+      ProcessTags: processTags.serialized
     }
   })
 

packages/dd-trace/test/span_stats.spec.js

@@ -24,6 +24,7 @@ const {
   DEFAULT_SPAN_NAME,
   DEFAULT_SERVICE_NAME
 } = require('../src/encode/tags-processors')
+const processTags = require('../src/process-tags')
 
 // Mock spans
 const basicSpan = {
@@ -388,7 +389,8 @@ describe('SpanStatsProcessor', () => {
       Lang: 'javascript',
       TracerVersion: pkg.version,
       RuntimeID: processor.tags['runtime-id'],
-      Sequence: processor.sequence
+      Sequence: processor.sequence,
+      ProcessTags: processTags.serialized
     }))
   })
 
@@ -406,7 +408,8 @@ describe('SpanStatsProcessor', () => {
       Lang: 'javascript',
       TracerVersion: pkg.version,
       RuntimeID: processor.tags['runtime-id'],
-      Sequence: processor.sequence
+      Sequence: processor.sequence,
+      ProcessTags: processTags.serialized
     }))
   })
 })