feat(dbm): add dynamic_service propagation mode

index.d.ts

@@ -845,7 +845,7 @@ declare namespace tracer {
      * @env DD_DBM_PROPAGATION_MODE
      * Programmatic configuration takes precedence over the environment variables listed above.
      */
-    dbmPropagationMode?: 'disabled' | 'service' | 'full'
+    dbmPropagationMode?: 'disabled' | 'service' | 'full' | 'dynamic_service'
 
     /**
      * Whether to enable Data Streams Monitoring.

index.d.v5.ts

@@ -912,7 +912,7 @@ declare namespace tracer {
      * @env DD_DBM_PROPAGATION_MODE
      * Programmatic configuration takes precedence over the environment variables listed above.
      */
-    dbmPropagationMode?: 'disabled' | 'service' | 'full'
+    dbmPropagationMode?: 'disabled' | 'service' | 'full' | 'dynamic_service'
 
     /**
      * Whether to enable Data Streams Monitoring.

packages/dd-trace/src/plugins/database.js

@@ -97,8 +97,9 @@ class DatabasePlugin extends StoragePlugin {
 
     let dbmComment = servicePropagation
 
-    // Add propagation hash if both process tags and SQL base hash injection are enabled
-    if (propagationHash.isEnabled() && this.config['dbm.injectSqlBaseHash']) {
+    // Add propagation hash if process tags are enabled and either SQL base hash injection is enabled
+    // or dynamic_service mode implicitly enables it
+    if (propagationHash.isEnabled() && (this.config['dbm.injectSqlBaseHash'] || mode === 'dynamic_service')) {
       const hashBase64 = propagationHash.getHashBase64()
       if (hashBase64) {
         dbmComment += `,ddsh='${hashBase64}'`
@@ -107,7 +108,7 @@ class DatabasePlugin extends StoragePlugin {
       }
     }
 
-    if (disableFullMode || mode === 'service') {
+    if (disableFullMode || mode === 'service' || mode === 'dynamic_service') {
       return dbmComment
     } else if (mode === 'full') {
       span.setTag('_dd.dbm_trace_injected', 'true')

packages/dd-trace/test/plugins/database-dbm-hash.spec.js

@@ -164,6 +164,54 @@ describe('DatabasePlugin DBM Hash', () => {
     })
   })
 
+  describe('dynamic_service mode', () => {
+    beforeEach(() => {
+      plugin.config.dbmPropagationMode = 'dynamic_service'
+    })
+
+    it('should inject hash even when dbm.injectSqlBaseHash is false', () => {
+      plugin.config['dbm.injectSqlBaseHash'] = false
+
+      const comment = plugin.createDbmComment(span, 'test-service')
+
+      assert.ok(comment, 'Comment should be created')
+      assert.ok(comment.includes("ddsh='AQIDBAUG'"),
+        'dynamic_service should inject hash regardless of injectSqlBaseHash')
+    })
+
+    it('should not inject traceparent', () => {
+      const comment = plugin.createDbmComment(span, 'test-service')
+
+      assert.ok(comment, 'Comment should be created')
+      assert.ok(!comment.includes('traceparent='), 'dynamic_service should not inject traceparent')
+    })
+
+    it('should behave identically to service + injectSqlBaseHash=true', () => {
+      plugin.config['dbm.injectSqlBaseHash'] = false
+
+      const dynamicComment = plugin.createDbmComment(span, 'test-service')
+
+      // Reset span tags and compare with service + injectSqlBaseHash=true
+      span._tags = {}
+      plugin.config.dbmPropagationMode = 'service'
+      plugin.config['dbm.injectSqlBaseHash'] = true
+
+      const serviceComment = plugin.createDbmComment(span, 'test-service')
+
+      assert.strictEqual(dynamicComment, serviceComment,
+        'dynamic_service should produce identical output to service + injectSqlBaseHash=true')
+    })
+
+    it('should not inject hash when propagation hash is disabled', () => {
+      propagationHash.isEnabled = () => false
+
+      const comment = plugin.createDbmComment(span, 'test-service')
+
+      assert.ok(comment, 'Comment should still be created')
+      assert.ok(!comment.includes('ddsh='), 'Should not inject hash when propagation hash is disabled')
+    })
+  })
+
   describe('control matrix for process tags and SQL base hash', () => {
     it('should inject hash when both propagateProcessTags and injectSqlBaseHash are enabled', () => {
       // DD_EXPERIMENTAL_PROPAGATE_PROCESS_TAGS_ENABLED=true + DD_DBM_INJECT_SQL_BASEHASH=true