Run Java JFR scenario with Datadog profiler

Author: r1viollet

analysis/jfr.go

@@ -42,13 +42,12 @@ func FromJFR(data []byte) (*ProfileSet, error) {
 			continue
 		}
 
-		fields, err := decodeJFREventFields(event.Type, event.Data, &p.TypeMap)
-		if err != nil {
-			return nil, fmt.Errorf("jfr decode %s: %w", event.Type.Name, err)
-		}
-
 		switch event.Type.Name {
 		case "jdk.ExecutionSample", "datadog.ExecutionSample":
+			fields, err := decodeJFREventFields(event.Type, event.Data, &p.TypeMap)
+			if err != nil {
+				return nil, fmt.Errorf("jfr decode %s: %w", event.Type.Name, err)
+			}
 			addJFRCPU(ps, p, fields)
 		}
 	}

scenarios/java_cpu_jfr/Dockerfile

@@ -2,21 +2,43 @@ FROM eclipse-temurin:21-jdk
 
 WORKDIR /app
 
-# Copy and compile the Java source
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends curl ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+
+# Install the Datadog Java tracer, which carries the Datadog native Java
+# profiler (ddprof).  The profiler writes Datadog-specific JFR events such as
+# datadog.ExecutionSample; this scenario validates that prof-correctness can
+# consume those recordings directly.
+RUN curl -fsSL -o /app/dd-java-agent.jar https://dtdg.co/latest-java-tracer
+
 COPY ./scenarios/java_cpu_jfr/DummyApp.java .
 RUN javac DummyApp.java
 
-# Force re-run of the next layer when the cache date changes.
-ARG CACHE_DATE=2024-01-01
-
-# EXECUTION_TIME_SEC is injected by the test harness; default to 30 s.
-ENV EXECUTION_TIME_SEC=30
+# EXECUTION_TIME_SEC is injected by the test harness; default to 60 s.
+ENV EXECUTION_TIME_SEC=60
 
-# Run with built-in JFR.
-#   -XX:+FlightRecorder          : enable JFR (no-op on JDK 11+ where it's always on)
-#   -XX:StartFlightRecording=... : start a continuous recording; dump on JVM exit.
-#   settings=profile             : enable CPU/alloc/lock profiling at low overhead.
-CMD java \
-    -XX:+FlightRecorder \
-    "-XX:StartFlightRecording=filename=/app/data/profile.jfr,dumponexit=true,settings=profile,name=correctness" \
-    DummyApp
+# Run the app under the Datadog Java profiler and use the tracer's built-in
+# debug dump path to persist the JFR snapshot locally. The prof-correctness
+# harness finds the timestamped dd-profiler-debug-*.jfr file by regex.
+CMD sh -eu -c '\
+    mkdir -p /app/data/dumps /app/data/tmp; \
+    java \
+      -javaagent:/app/dd-java-agent.jar \
+      -Ddd.service=prof-correctness-java-cpu-jfr \
+      -Ddd.env=local \
+      -Ddd.trace.enabled=false \
+      -Ddd.profiling.enabled=true \
+      -Ddd.profiling.ddprof.enabled=true \
+      -Ddd.profiling.ddprof.cpu.enabled=true \
+      -Ddd.profiling.ddprof.wall.enabled=false \
+      -Ddd.profiling.upload.period=30 \
+      -Ddd.profiling.upload.timeout=1 \
+      -Ddd.profiling.start-force-first=true \
+      -Ddd.profiling.tempdir=/app/data/tmp \
+      -Ddd.profiling.debug.dump_path=/app/data/dumps \
+      -Ddd.profiling.url=http://127.0.0.1:8126/ \
+      -Ddd.telemetry.enabled=false \
+      -Ddd.jmxfetch.enabled=false \
+      DummyApp \
+'

scenarios/java_cpu_jfr/DummyApp.java

@@ -2,7 +2,7 @@
  * Simple CPU-intensive app for JFR correctness testing.
  *
  * Continuously computes Fibonacci numbers to keep the CPU busy.
- * The JFR recording is started by the JVM flags passed on the command line;
+ * The Datadog Java profiler is started by the JVM flags passed on the command line;
  * this app just runs for the requested duration and exits.
  *
  * The EXECUTION_TIME_SEC environment variable (default: 30) controls how long

scenarios/java_cpu_jfr/expected_profile.json

@@ -1,6 +1,6 @@
 {
   "test_name": "java_cpu_jfr",
-  "pprof-regex": ".*\\.jfr$",
+  "pprof-regex": "^dd-profiler-debug-.*\\.jfr$",
   "stacks": [
     {
       "profile-type": "cpu",