Application Profiling

Overview of Custom Logging with Apache Flink
Profiling with Java Flight Recorder
Profiling with JITWatch

Overview of Custom Logging with Apache Flink

Each standalone JobManager, TaskManager, HistoryServer, and ZooKeeper daemon redirects stdout and stderr to a file with a .out filename suffix and writes internal logging to a file with a .log suffix. Java options configured by the user in env.java.opts, env.java.opts.jobmanager, and env.java.opts.taskmanager can likewise define log files with use of the script variable FLINK_LOG_PREFIX and by enclosing the options in double quotes for late evaluation. Log files using FLINK_LOG_PREFIX are rotated along with the default .out and .log files.

Profiling with Java Flight Recorder

Java Flight Recorder is a profiling and event collection framework built into the Oracle JDK. Java Mission Control is an advanced set of tools that enables efficient and detailed analysis of the extensive of data collected by Java Flight Recorder. Example configuration:

env.java.opts: "-XX:+UnlockCommercialFeatures -XX:+UnlockDiagnosticVMOptions -XX:+FlightRecorder -XX:+DebugNonSafepoints -XX:FlightRecorderOptions=defaultrecording=true,dumponexit=true,dumponexitpath=${FLINK_LOG_PREFIX}.jfr"

Profiling with JITWatch

JITWatch is a log analyser and visualizer for the Java HotSpot JIT compiler used to inspect inlining decisions, hot methods, bytecode, and assembly. Example configuration:

env.java.opts: "-XX:+UnlockDiagnosticVMOptions -XX:+TraceClassLoading -XX:+LogCompilation -XX:LogFile=${FLINK_LOG_PREFIX}.jit -XX:+PrintAssembly"