JVM Profiling with Java Flight Recorder

Use this skill when a Java application's CPU time, latency, allocation rate, garbage collection, heap growth, or thread contention needs evidence rather than guesses. It is deliberately independent of a build system: replace the example application command and output paths with the command used to launch the service.

Choose the tool

• Java Flight Recorder (JFR) is the low-overhead event recorder built into modern JDKs. Use it for a bounded production investigation, startup or intermittent latency, GC/safepoint behavior, allocation rates, locks, and correlated JVM/OS events.
• JDK Mission Control (JMC) is the GUI for opening and analyzing .jfr recordings. It is especially useful when the problem happened in the past or on another host.
• A useful default sequence is: establish a baseline, collect a short JFR recording, inspect it in JDK Mission Control, and take a heap dump only when the evidence points to a live heap/object-graph question. Do not treat a profiler's percentage as a diagnosis by itself.

Official repository resources:

• Java Flight Recorder and JDK Mission Control — the repository's JFR/JMC link.
• The jcmd syntax and options are versioned with the JDK; use the documentation for the JDK actually running the target JVM (for example, the JDK 25 jcmd reference).

Before collecting data