Heapster provides an agent library to do heap profiling for JVM processes with output compatible with Google perftools. The goal of Heapster is to be able to do meaningful (sampled) heap profiling in a production setting.
Currently it allows for profiling similar to the TCMalloc library, e.g.:
$ HEAPSTER_PROFILE=/tmp/OUT java -Xbootclasspath/a:. -agentlib:heapster Test
$ pprof /tmp/OUT
Welcome to pprof! For help, type 'help'.
(pprof) top
Total: 2001520 samples
2000024 99.9% 99.9% 2000048 99.9% LTest;main
1056 0.1% 100.0% 1056 0.1% Ljava/lang/Object;
296 0.0% 100.0% 296 0.0% Ljava/lang/String;toCharArray
104 0.0% 100.0% 136 0.0% Ljava/lang/Shutdown;
By default, Heapster samples every 512 kB, this can be changed with
the environment variable HEAPSTER_SAMPLE_PERIOD (in bytes).
This is still work in progress.
If you use Ostrich, and run your program with heapster, you can generate runtime heap profiles like so:
$ curl 'localhost:9990/pprof/heap?pause=10&sample_period=1024' > /tmp/prof
This will collect heap growth for 10 seconds, with a sampling period of 1kB.