Note: Travis has removed the support for Oracle JDK 8. Therefore the build status is removed temporarily.

Converting JFR Method Profiling Samples to FlameGraph compatible format.

This is a simple application to read Method Profiling Samples from Java Flight Recorder dump and convert those Stack Traces to FlameGraph compatible format.

This application uses the unsupported JMC Parser.

See my blog post on "Flame Graphs with Java Flight Recordings" for more details.

Prerequisites

This project depends on Oracle JDK 8. Therefore, make sure that JAVA_HOME is set to Oracle JDK 8.

How to build and install

Build and install jfr-flame-graph app using

./gradlew installDist

This will install the executable into ./build/install/jfr-flame-graph/bin.

You can add this location to your PATH.

Clone FlameGraph repository

Clone Brendan's FlameGraph repository and set the environment variable FLAMEGRAPH_DIR to FlameGraph directory

git clone https://github.com/brendangregg/FlameGraph.git
export FLAMEGRAPH_DIR=/path/to/FlameGraph

How to generate a Flame Graph

There are helper scripts, to generate the flame graphs in ./build/install/jfr-flame-graph/bin directory.

For example:

./create_flamegraph.sh -f /tmp/highcpu.jfr -i > flamegraph.svg

Open the SVG file in your web browser.

Use -h with scripts to see the available options.

For example:

$ ./jfr-flame-graph -h
  Usage: JFRToFlameGraphWriter [options]
    Options:
      -d, --decompress
        Decompress the JFR file
        Default: false
      -et, --end-timestamp
        End timestamp in seconds for filtering
        Default: 9223372036854775807
      -e, --event
        Type of event used to generate the flamegraph
        Default: cpu
        Possible Values: [cpu, allocation-tlab, allocation-outside-tlab, exceptions, monitor-blocked, io]
      -h, --help
        Display Help
      -ha, --hide-arguments
        Hide arguments in methods
        Default: false
      -i, --ignore-line-numbers
        Ignore Line Numbers in Stack Frame
        Default: false
    * -f, --jfrdump
        Java Flight Recorder Dump
      -l, --live
        Export stack trace sample timestamp (in json output type)
        Default: false
      -o, --output
        Output file
      -ot, --output-type
        Output type
        Default: folded
        Possible Values: [folded, json]
      -j, --print-jfr-details
        Print JFR details and exit
        Default: false
      -t, --print-timestamp
        Print timestamp in JFR Details
        Default: false
      -rv, --show-return-value
        Show return value for methods in the stack
        Default: false
      -st, --start-timestamp
        Start timestamp in seconds for filtering
        Default: -9223372036854775808
      -sn, --use-simple-names
        Use simple names instead of qualified names in the stack
        Default: false

License

Licensed under the Apache License, Version 2.0