As explained on the Azul's site, jHiccup captures the aggregate effects of the Java Virtual Machine (JVM), operating system, hypervisor (if used) and hardware on application stalls and response time.
This tool records platform pause/stall into log files that you can import into a MS Excel file:
Next you can plot platform "hiccup" and percentiles as illustrated below:
|chart from MS Excel|
This chart shows that during a 25 seconds benchmark, 99% of the latencies collected are lesser than 300 milliseconds, with a peak of half a second ! Such values indicate that we are not in the case of a dedicated/quiet system, and there must be some background activities (actually, i ran this benchmark during a Windows 7 user session with mail, browser and other usual softwares).
As you can guess, such a tool is really useful to check:
- that your JVM is running on a dedicated or quiet system
- that application response time behavior are not influenced by the platform