应用程序分析

• 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 filewith a .out filename suffix and writes internal logging to a file with a .log suffix. Java options configured by theuser in env.java.opts, env.java.opts.jobmanager, env.java.opts.taskmanager and env.java.opts.historyserver can likewise define log files withuse of the script variable FLINK_LOG_PREFIX and by enclosing the options in double quotes for late evaluation. Log filesusing 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 Controlis an advanced set of tools that enables efficient and detailed analysis of the extensive of data collected by JavaFlight 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 JITcompiler 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"