async-profiler-hot-cold-flamegraph-example

Hot/Cold Flame Graph is an visualization which combines both on-CPU and off-CPU flame graphs.

This is an example of a Hot/Cold Flame Graph generated by async-profiler.

• demo.html
• demo_threads.html

How to generate

1. Launch containers

   docker-compose up -d --build

2. Exec async-profiler to generate .jfr file in demo container

   # external shell
   curl http://localhost:9090/demo 
   # (optional) use ab command instead of curl

   docker-compose exec demo bash
   /var/lib/async-profiler/profiler.sh -e wall,alloc,lock -d 60 -t -i 1ms -o jfr -f "demo.jfr" $(pgrep -nx java)

   -e wall option must be used to sample regardless of thread state (on-CPU or off-CPU).

   -t option should be used to avoid confusing off-CPU and on-CPU comparisons.

3. Convert .jfr to .html

   java -cp converter.jar jfr2flame --hotcold demo.jfr demo.html
   java -cp converter.jar jfr2flame --hotcold --threads demo.jfr demo_threads.html