feat: Core Tracing supportability metrics (#3610)

Author: amychisholm03

lib/metrics/names.js

@@ -55,6 +55,11 @@ const MEMORY = {
   USED_NONHEAP: 'Memory/NonHeap/Used'
 }
 
+const CORE_TRACING = {
+  PG: `${SUPPORTABILITY.NODEJS}/PartialGranularity`,
+  FG: `${SUPPORTABILITY.NODEJS}/FullGranularity`,
+}
+
 const CPU = {
   SYSTEM_TIME: 'CPU/System Time',
   SYSTEM_UTILIZATION: 'CPU/System/Utilization',
@@ -371,6 +376,7 @@ module.exports = {
   CASSANDRA,
   CLIENT_APPLICATION: 'ClientApplication',
   CONTROLLER: 'Controller',
+  CORE_TRACING,
   CPU,
   CUSTOM: 'Custom',
   CUSTOM_EVENTS,

lib/samplers/index.js

@@ -11,6 +11,7 @@ const AlwaysOnSampler = require('./always-on-sampler')
 const TraceIdRatioBasedSampler = require('./ratio-based-sampler')
 const logger = require('../logger').child({ component: 'samplers' })
 const { PARTIAL_TYPES } = require('../transaction')
+const { CORE_TRACING: { PG, FG } } = require('#agentlib/metrics/names.js')
 
 /**
  * Manages the different samplers used for distributed tracing sampling decisions.
@@ -19,7 +20,8 @@ const { PARTIAL_TYPES } = require('../transaction')
  * @typedef {object} Samplers
  * @property {boolean} fullEnabled Whether full granularity sampling is enabled.
  * @property {boolean} partialEnabled Whether partial granularity sampling is enabled.
- * @property {AdaptiveSampler|null} adaptiveSampler The global adaptive sampler instance, this is shared if `sampling_target` is not defined for a sampler type of `adaptive`.
+ * @property {AdaptiveSampler|null} adaptiveSampler The global adaptive sampler instance;
+ * this is shared if `sampling_target` is not defined for a sampler type of `adaptive`.
  * @property {Sampler} root The root sampler for traces originating in application.
  * @property {Sampler} remoteParentSampled The sampler for traces with a remote parent that is sampled.
  * @property {Sampler} remoteParentNotSampled The sampler for traces with a remote parent that is not sampled.
@@ -39,6 +41,40 @@ class Samplers {
     this.partialRoot = this.determineSampler({ agent, sampler: 'root', isPartial: true })
     this.partialRemoteParentSampled = this.determineSampler({ agent, sampler: 'remote_parent_sampled', isPartial: true })
     this.partialRemoteParentNotSampled = this.determineSampler({ agent, sampler: 'remote_parent_not_sampled', isPartial: true })
+    this.#sendCoreTracingMetrics(agent)
+  }
+
+  /**
+   * Sends relevant Core Tracing metrics on startup in the form:
+   * `Supportability/Nodejs/<granularity type>/<sampler section>/<sampler type>`
+   * @param {Agent} agent agent instance with these `Samplers`
+   */
+  #sendCoreTracingMetrics(agent) {
+    const metrics = agent.metrics
+    if (this.partialEnabled) {
+      // Supportability/Nodejs/PartialGranularity/<sampler section>/<sampler type>
+      metrics.getOrCreateMetric(`${PG}/Root/${this.#determineSamplerType(this.partialRoot)}`)
+      metrics.getOrCreateMetric(`${PG}/RemoteParentSampled/${this.#determineSamplerType(this.partialRemoteParentSampled)}`)
+      metrics.getOrCreateMetric(`${PG}/RemoteParentNotSampled/${this.#determineSamplerType(this.partialRemoteParentNotSampled)}`)
+    }
+    if (this.fullEnabled) {
+      // Supportability/Nodejs/PartialGranularity/<sampler section>/<sampler type>
+      metrics.getOrCreateMetric(`${FG}/Root/${this.#determineSamplerType(this.root)}`)
+      metrics.getOrCreateMetric(`${FG}/RemoteParentSampled/${this.#determineSamplerType(this.remoteParentSampled)}`)
+      metrics.getOrCreateMetric(`${FG}/RemoteParentNotSampled/${this.#determineSamplerType(this.remoteParentNotSampled)}`)
+    }
+  }
+
+  /**
+   *
+   * @param {Sampler} sampler an instance of a Sampler
+   * @returns {string} 'Adaptive/Shared', 'Adaptive', 'AlwaysOn', 'AlwaysOff', or 'TraceIdRatioBased'
+   */
+  #determineSamplerType(sampler) {
+    if (sampler === this.adaptiveSampler) {
+      return 'Adaptive/Shared'
+    }
+    return sampler.toString().replace('Sampler', '')
   }
 
   /**

test/integration/agent/serverless-harvest.test.js

@@ -122,7 +122,8 @@ test('sending metrics', async (t) => {
     'metric_data',
     function checkData(payload) {
       plan.ok(payload, 'should have a payload')
-      plan.deepStrictEqual(payload[3][0][0], { name: 'TEST/discard' }, 'should have test metric')
+      // First 3 are FullGranularity supportability metrics
+      plan.deepStrictEqual(payload[3][3][0], { name: 'TEST/discard' }, 'should have test metric')
     }
   )
 

test/integration/module-loading/module-loading.test.js

@@ -133,7 +133,8 @@ test('Should create usage metric onRequire for built-in', (t) => {
   assert.ok(onRequireMetric)
   assert.equal(onRequireMetric.callCount, 1)
   const domainMetrics = Object.keys(agent.metrics._metrics.unscoped)
-  assert.equal(domainMetrics.length, 1, 'should not log a version metric for a built-in')
+  // 3 of these are FullGranularity supportability metrics
+  assert.equal(domainMetrics.length, 4, 'should not log a version metric for a built-in')
 })
 
 test('should instrument a local package', (t, end) => {

test/integration/utilization/common.js

@@ -11,13 +11,15 @@ const JSONbig = require('json-bigint')({ useNativeBigInt: true })
 const path = require('path')
 
 function checkMetrics(agent, expectedMetrics) {
+  const metrics = agent.metrics
   if (!expectedMetrics) {
-    assert.equal(agent.metrics._metrics.toJSON().length, 0, 'should not have any metrics')
+    // 3 FullGranularity supportability metrics will always exist
+    assert.equal(metrics._metrics.toJSON().length, 3, 'should not have any additional metrics')
     return
   }
 
   Object.keys(expectedMetrics).forEach(function (expectedMetric) {
-    const metric = agent.metrics.getOrCreateMetric(expectedMetric)
+    const metric = metrics.getOrCreateMetric(expectedMetric)
     assert.equal(
       metric.callCount,
       expectedMetrics[expectedMetric].call_count,