feat(config): enable startup logs by default (#7474)

bm1549 · claude · web-flow · commit 46aa1f04413c · 2026-03-18T13:03:13.000-04:00
* feat(config): enable startup logs by default

Changed the default value of startupLogs from false to true. Startup logs
provide helpful diagnostic information about tracer configuration and should
be enabled by default to improve observability and debugging experience.

Changes:
- Updated supported-configurations.json to set startupLogs default to true
- Updated config test expectations to reflect new default

Co-Authored-By: Claude Sonnet 4.6 &lt;noreply@anthropic.com&gt;

* fix(test): disable startup logs in RASP integration tests

The startup log line was being captured by the stdioHandler and
triggering "Unexpected output in stdout/stderr after blocking request"
assertion failures.

Co-Authored-By: Claude Opus 4.6 (1M context) &lt;noreply@anthropic.com&gt;

* fix(config): update DD_TRACE_STARTUP_LOGS implementation level to C

Co-Authored-By: Claude Opus 4.6 (1M context) &lt;noreply@anthropic.com&gt;

* fix(config): gate startup logs default behind DD_MAJOR version check

Breaking changes must be behind a version flag since code is shared
between versions. Keep supported-configurations.json default as false
and override in defaults.js with DD_MAJOR &gt;= 6 so v5 retains the
original behavior.

Co-Authored-By: Claude Opus 4.6 (1M context) &lt;noreply@anthropic.com&gt;

* test(config): use DD_MAJOR to determine startupLogs default in tests

Co-Authored-By: Claude Sonnet 4.6 &lt;noreply@anthropic.com&gt;

---------

Co-authored-by: Claude Sonnet 4.6 &lt;noreply@anthropic.com&gt;
diff --git a/integration-tests/appsec/index.spec.js b/integration-tests/appsec/index.spec.js
@@ -37,6 +37,7 @@ describe('RASP', () => {
           DD_APPSEC_RASP_ENABLED: 'true',
           DD_APPSEC_RULES: path.join(cwd, 'appsec/rasp/rasp_rules.json'),
           DD_APPSEC_RASP_COLLECT_REQUEST_BODY: String(collectRequestBody),
+          DD_TRACE_STARTUP_LOGS: 'false',
         },
       }, stdOutputHandler, stdOutputHandler)
       axios = Axios.create({ baseURL: proc.url })
diff --git a/packages/dd-trace/src/config/defaults.js b/packages/dd-trace/src/config/defaults.js
@@ -2,6 +2,7 @@
 
 const pkg = require('../pkg')
 const { isFalse, isTrue } = require('../util')
+const { DD_MAJOR } = require('../../../../version')
 const { getEnvironmentVariable: getEnv } = require('./helper')
 
 const {
@@ -117,6 +118,7 @@ const defaultsWithoutSupportedConfigurationEntry = {
 // TODO: These entries should be removed. They are off by default
 // because they rely on other configs.
 const defaultsWithConditionalRuntimeBehavior = {
+  startupLogs: DD_MAJOR >= 6,
   isGitUploadEnabled: false,
   isImpactedTestsEnabled: false,
   isIntelligentTestRunnerEnabled: false,
diff --git a/packages/dd-trace/test/config/index.spec.js b/packages/dd-trace/test/config/index.spec.js
@@ -578,7 +578,7 @@ describe('Config', () => {
       { name: 'spanAttributeSchema', value: 'v0', origin: 'default' },
       { name: 'spanComputePeerService', value: false, origin: 'calculated' },
       { name: 'spanRemoveIntegrationFromService', value: false, origin: 'default' },
-      { name: 'startupLogs', value: false, origin: 'default' },
+      { name: 'startupLogs', value: DD_MAJOR >= 6, origin: 'default' },
       { name: 'stats.enabled', value: false, origin: 'calculated' },
       { name: 'tagsHeaderMaxLength', value: 512, origin: 'default' },
       { name: 'telemetry.debug', value: false, origin: 'default' },
