fix(otel): align MDC log-correlation keys with JS and Python SDKs

otel-plugin/src/main/java/software/amazon/lambda/durable/otel/ExecutionOtelPlugin.java

@@ -150,7 +150,7 @@ public ExecutionOtelPlugin(SdkTracerProviderBuilder tracerProviderBuilder, Conte
      *
      * @param tracerProviderBuilder the tracer provider builder (ID generator will be overridden)
      * @param contextExtractor extracts parent trace context from the Lambda environment
-     * @param enableMdc if true, injects traceId/spanId/traceSampled into SLF4J MDC for log correlation
+     * @param enableMdc if true, injects traceId/spanId/otelTraceSampled into SLF4J MDC for log correlation
      * @param workflowSpanName the name for the Workflow root span
      */
     public ExecutionOtelPlugin(

otel-plugin/src/main/java/software/amazon/lambda/durable/otel/InvocationOtelPlugin.java

@@ -165,7 +165,7 @@ public InvocationOtelPlugin(SdkTracerProviderBuilder tracerProviderBuilder, Cont
      *
      * @param tracerProviderBuilder the tracer provider builder (ID generator will be overridden)
      * @param contextExtractor extracts parent trace context from the Lambda environment
-     * @param enableMdc if true, injects traceId/spanId/traceSampled into SLF4J MDC for log correlation
+     * @param enableMdc if true, injects traceId/spanId/otelTraceSampled into SLF4J MDC for log correlation
      */
     public InvocationOtelPlugin(
             SdkTracerProviderBuilder tracerProviderBuilder, ContextExtractor contextExtractor, boolean enableMdc) {
@@ -177,7 +177,7 @@ public InvocationOtelPlugin(
      *
      * @param tracerProviderBuilder the tracer provider builder (ID generator will be overridden)
      * @param contextExtractor extracts parent trace context from the Lambda environment
-     * @param enableMdc if true, injects traceId/spanId/traceSampled into SLF4J MDC for log correlation
+     * @param enableMdc if true, injects traceId/spanId/otelTraceSampled into SLF4J MDC for log correlation
      * @param workflowSpanName the name for the Workflow span
      */
     public InvocationOtelPlugin(

otel-plugin/src/main/java/software/amazon/lambda/durable/otel/MdcSpanEnricher.java

@@ -11,12 +11,12 @@
  * <p>When used with structured logging (Log4j2 JSON, Logback JSON), these MDC fields appear in every log line, enabling
  * tools like CloudWatch Application Signals and Datadog to correlate logs with traces.
  *
- * <p>MDC keys injected:
+ * <p>MDC keys injected (aligned with the JS and Python SDK OTel plugins):
  *
  * <ul>
- *   <li>{@code trace_id} — the W3C trace ID (32 hex chars)
- *   <li>{@code span_id} — the current span ID (16 hex chars)
- *   <li>{@code traceSampled} — whether the trace is sampled (true/false)
+ *   <li>{@code traceId} — the W3C trace ID (32 hex chars)
+ *   <li>{@code spanId} — the current span ID (16 hex chars)
+ *   <li>{@code otelTraceSampled} — whether the trace is sampled (true/false)
  * </ul>
  *
  * <p>Usage: Call {@link #inject()} in {@code onUserFunctionStart} (after span is active) and {@link #clear()} in
@@ -28,9 +28,14 @@
 @Deprecated
 public final class MdcSpanEnricher {
 
-    public static final String MDC_TRACE_ID = "trace_id";
-    public static final String MDC_SPAN_ID = "span_id";
-    public static final String MDC_TRACE_SAMPLED = "traceSampled";
+    // MDC key names are aligned with the JS and Python SDK OTel plugins
+    // (enrichLogContext -> traceId/spanId/otelTraceSampled) so log-trace
+    // correlation uses one consistent field schema across all three SDKs.
+    // Note: SLF4J MDC values are always strings, so otelTraceSampled is the
+    // string "true"/"false" here (a boolean in the JS/Python log records).
+    public static final String MDC_TRACE_ID = "traceId";
+    public static final String MDC_SPAN_ID = "spanId";
+    public static final String MDC_TRACE_SAMPLED = "otelTraceSampled";
 
     private MdcSpanEnricher() {}
 

otel-plugin/src/test/java/software/amazon/lambda/durable/otel/MdcSpanEnricherTest.java

@@ -20,6 +20,16 @@ void cleanup() {
         MDC.clear();
     }
 
+    @Test
+    void mdcKeyNames_matchJsAndPythonSchema() {
+        // The JS (enrichLogContext) and Python (OtelContextLogFilter) plugins emit
+        // traceId / spanId / otelTraceSampled. Java's MDC keys must match so all
+        // three SDKs share one log-trace-correlation field schema.
+        assertEquals("traceId", MdcSpanEnricher.MDC_TRACE_ID);
+        assertEquals("spanId", MdcSpanEnricher.MDC_SPAN_ID);
+        assertEquals("otelTraceSampled", MdcSpanEnricher.MDC_TRACE_SAMPLED);
+    }
+
     @Test
     void clear_removesAllMdcKeys() {
         MDC.put(MdcSpanEnricher.MDC_TRACE_ID, "abc123");