Planned lessonMID-008-L02

Java Flight Recorder

On This Lesson 4 topics

This lesson is planned. The outline below lists the topics it will cover. The full lesson has not been published yet.

In this lesson

record JFR data from a running service.

JFR is a low-overhead event recorder built into the JVM, with a continuous mode.
Start at launch: -XX:StartFlightRecording=filename=shop.jfr,duration=120s, or on a live process: jcmd <pid> JFR.start, then JFR.dump.
Events: CPU samples, allocation, GC, locks, I/O, thread states, exceptions.
Profiles (default vs profile settings) trade detail against overhead.
Verify option details for your JDK before recording.

Draft outline details

text

jcmd <pid> JFR.start name=shop settings=profile duration=120s filename=shop.jfr

Why is JFR suitable for production?

Show answer

Low overhead and built into the JVM.

Apply this lesson with the module's lab, exercises and quiz.

Marking a lesson complete is optional and you can undo it any time. Your progress stays in this browser.