trandersen-ufst / javaflames

One file java script for visualizing JDK flight recorder execution logs as flamegraphs without any dependencies except Java and a browser.

Flamegraph from JFR logs

Simple one file Java script to generate flamegraphs from Java flight recordings without installing Perl and the Brendan Gregg scripts.

It also comes with a separate script to start profiling a java process using FlightRecorder and then call the flamegraph script.

Usage

With a fairly recent Java version installed simply run: java JavaFlames.java <path to jfr recording file>

This launches an http server serving the index.html file and endpoint for the folded format extracted from the JFR logs. The script then opens up a browser showing the results.

Alternatively if you don't have an existing JFR recording you can also start the Profile.java script to start profiling a java process generating the JFR file and then triggering flamegraph generation.

java Profile.java <pid> [<duration in seconds>]

The default profiling duration unless specified is 30 seconds.

Credits

Brendan Gregg for introducing the concept of flamegraphs and https://github.com/spiermar/d3-flame-graph for the javascript/html implementation.