fix: add data_streams_enabled to startup log output (#7454)

johannbotha · web-flow · commit 52c89d2c322b · 2026-02-06T21:58:15.000+01:00
* Add data_streams_enabled to startup log output

Go, Java, and .NET tracers already include data_streams_enabled in
the DATADOG TRACER CONFIGURATION startup log. This adds parity for
the Node.js tracer, making it easier to debug DSM configuration
issues in customer environments.

* Add test coverage for data_streams_enabled in startup log

Tests the three key scenarios:
1. env var true, config unset → true (env var applies)
2. env var unset, config true → true (code option applies)
3. env var true, config false → false (code option takes precedence)

* Add dsmEnabled to TracerOptions interface

Exposes dsmEnabled as a documented, first-class option in dd.init().
The config system already supports this internally — this change just
makes it visible in the public TypeScript types.

When not provided, the value of DD_DATA_STREAMS_ENABLED env var is
used. When explicitly set, the code option takes precedence over the
env var (consistent with all other config options).
diff --git a/index.d.ts b/index.d.ts
@@ -760,6 +760,14 @@ declare namespace tracer {
      */
     dbmPropagationMode?: 'disabled' | 'service' | 'full'
 
+    /**
+     * Whether to enable Data Streams Monitoring.
+     * Can also be enabled via the DD_DATA_STREAMS_ENABLED environment variable.
+     * When not provided, the value of DD_DATA_STREAMS_ENABLED is used.
+     * @default false
+     */
+    dsmEnabled?: boolean
+
     /**
      * Configuration of the AppSec protection. Can be a boolean as an alias to `appsec.enabled`.
      */
diff --git a/packages/dd-trace/src/startup-log.js b/packages/dd-trace/src/startup-log.js
@@ -75,6 +75,7 @@ function tracerInfo () {
     profiling_enabled: config.profiling?.enabled === 'true' || config.profiling?.enabled === 'auto',
     integrations_loaded: Object.keys(pluginManager._pluginsByName),
     appsec_enabled: !!config.appsec.enabled,
+    data_streams_enabled: !!config.dsmEnabled,
   }
 
   return out
diff --git a/packages/dd-trace/test/startup-log.spec.js b/packages/dd-trace/test/startup-log.spec.js
@@ -51,6 +51,7 @@ describe('startup logging', () => {
       runtimeMetrics: true,
       startupLogs: true,
       appsec: { enabled: true },
+      dsmEnabled: true,
     })
     setSamplingRules([
       new SamplingRule({ name: 'rule1', sampleRate: 0.4 }),
@@ -98,6 +99,7 @@ describe('startup logging', () => {
       profiling_enabled: false,
       integrations_loaded: ['http', 'fs', 'semver'],
       appsec_enabled: true,
+      data_streams_enabled: true,
     })
   })
 
@@ -106,6 +108,72 @@ describe('startup logging', () => {
   })
 })
 
+describe('data_streams_enabled', () => {
+  afterEach(() => {
+    delete process.env.DD_DATA_STREAMS_ENABLED
+  })
+
+  it('should be true when env var is true and config is unset', () => {
+    sinon.stub(console, 'info')
+    delete require.cache[require.resolve('../src/startup-log')]
+    const {
+      setStartupLogConfig,
+      setStartupLogPluginManager,
+      startupLog,
+    } = require('../src/startup-log')
+    process.env.DD_DATA_STREAMS_ENABLED = 'true'
+    process.env.DD_TRACE_STARTUP_LOGS = 'true'
+    setStartupLogConfig(getConfigFresh())
+    setStartupLogPluginManager({ _pluginsByName: {} })
+    startupLog()
+    /* eslint-disable-next-line no-console */
+    const infoStub = /** @type {sinon.SinonStub} */ (console.info)
+    const logObj = JSON.parse(infoStub.firstCall.args[0].replace('DATADOG TRACER CONFIGURATION - ', ''))
+    infoStub.restore()
+    assert.strictEqual(logObj.data_streams_enabled, true)
+  })
+
+  it('should be true when env var is not set and config is true', () => {
+    sinon.stub(console, 'info')
+    delete require.cache[require.resolve('../src/startup-log')]
+    const {
+      setStartupLogConfig,
+      setStartupLogPluginManager,
+      startupLog,
+    } = require('../src/startup-log')
+    delete process.env.DD_DATA_STREAMS_ENABLED
+    process.env.DD_TRACE_STARTUP_LOGS = 'true'
+    setStartupLogConfig(getConfigFresh({ dsmEnabled: true }))
+    setStartupLogPluginManager({ _pluginsByName: {} })
+    startupLog()
+    /* eslint-disable-next-line no-console */
+    const infoStub = /** @type {sinon.SinonStub} */ (console.info)
+    const logObj = JSON.parse(infoStub.firstCall.args[0].replace('DATADOG TRACER CONFIGURATION - ', ''))
+    infoStub.restore()
+    assert.strictEqual(logObj.data_streams_enabled, true)
+  })
+
+  it('should be false when env var is true but config is false', () => {
+    sinon.stub(console, 'info')
+    delete require.cache[require.resolve('../src/startup-log')]
+    const {
+      setStartupLogConfig,
+      setStartupLogPluginManager,
+      startupLog,
+    } = require('../src/startup-log')
+    process.env.DD_DATA_STREAMS_ENABLED = 'true'
+    process.env.DD_TRACE_STARTUP_LOGS = 'true'
+    setStartupLogConfig(getConfigFresh({ dsmEnabled: false }))
+    setStartupLogPluginManager({ _pluginsByName: {} })
+    startupLog()
+    /* eslint-disable-next-line no-console */
+    const infoStub = /** @type {sinon.SinonStub} */ (console.info)
+    const logObj = JSON.parse(infoStub.firstCall.args[0].replace('DATADOG TRACER CONFIGURATION - ', ''))
+    infoStub.restore()
+    assert.strictEqual(logObj.data_streams_enabled, false)
+  })
+})
+
 describe('profiling_enabled', () => {
   it('should be correctly logged', () => {
     [

Original file line number	Diff line number	Diff line change
`@@ -75,6 +75,7 @@ function tracerInfo () {`
`75`	`75`	`profiling_enabled: config.profiling?.enabled === 'true' \|\| config.profiling?.enabled === 'auto',`
`76`	`76`	`integrations_loaded: Object.keys(pluginManager._pluginsByName),`
`77`	`77`	`appsec_enabled: !!config.appsec.enabled,`
	`78`	`+ data_streams_enabled: !!config.dsmEnabled,`
`78`	`79`	`}`
`79`	`80`
`80`	`81`	`return out`