http://docs.oracle.com/javase/7/docs/technotes/samples/hprof.html
https://codeascraft.com/2015/05/12/four-months-of-statsd-jvm-profiler-a-retrospective/
https://codeascraft.com/2015/01/14/introducing-statsd-jvm-profiler-a-jvm-profiler-for-hadoop/
https://github.com/riemann/riemann-jvm-profiler
https://github.com/etsy/statsd-jvm-profiler
https://www.infoq.com/articles/java-profiling-with-open-source