I have been using JRockit since many years 2007. I find it slower than Hotspot, but it has been always better on diagnosis and analysis of problems. Since last summer, I have been working for an international telecommunication systems vendor. We design and implement various products for telecom operators, on top of HP OpenCall Convergent Communication Platform. I am fan of Open Source and Free Software, but this platform is running “only” with JRockit VM. We have tuning it for low latencies and runs very cool, but we have faced various problems, where JRockit has helped us a lot on troubleshooting.
I will describe here a few useful commands of JRCMD. JRCMD is a small command-line tool that can be used to interact with a running JRockit instance.
- Get a thread dump
- Memory utilization
- Memory analysis of heap on a per-class basis
- State of VM
- Create a flight recording
- Produce a heap dump