Java Profiling Tools

All required tools are downloaded on src directory. Oracle JDK 8 is required, you must get an installer from Oracle web page (a RPM installer) and change this line sudo rpm -U /vagrant/temp/jdk-8u241-linux-x64.rpm in Vagranfile before you create VM.

javaFlameGraph

Run gs-rest-service demo application with following options:

• java -XX:+UnlockDiagnosticVMOptions -XX:+DebugNonSafepoints -jar gs-rest-service-0.1.0.jar

Generate flame graph with javaFlameGraph tool.

• ./flame-gen.sh <PID>

You can get your Java application PID using jps command.

jfr-report-tool

Oracle JDK 8 is required. OpenJDK 8 does not include Java Flight Recorder.

Run gs-rest-service demo application with following options:

• java -XX:+UnlockCommercialFeatures -XX:+FlightRecorder -XX:+UnlockDiagnosticVMOptions -XX:+DebugNonSafepoints -XX:FlightRecorderOptions=stackdepth=1024 -jar gs-rest-service-0.1.0.jar

Now generate a new JFR recording with jcmd command.

• jcmd <PID> JFR.start name=myrecording settings=profile
• jcmd <PID> JFR.dump name=myrecording filename=$PWD/mydump.jfr
• jcmd <PID> JFR.stop name=myrecording

Generate flame graph with jfr-report-tool.

• ./jfr-report-tool -e none mydump.jfr

perf and perf-map-agent

Run gs-rest-service demo application with following options:

• java -XX:+PreserveFramePointer -XX:+UnlockDiagnosticVMOptions -XX:+DebugNonSafepoints -jar gs-rest-service-0.1.0.jar
• ./create-java-perf-map.sh <PID>
• perf record -F 99 -p <PID> -g
• perf script > out.perf
• ./FlameGraph/stackcollapse-perf.pl out.perf > out.folded
• ./FlameGraph/flamegraph.pl --color=java out.folded > graph.svg