Experiencing occasional long garbage collection delays, why?

Question

I\'m having a hard time dealing with a Java garbage collection problem, and interpreting the logs.

My application requires that no GC takes longer than 2 seconds, and id

Answer 1

I think you are having this UseConcMarkSweepGC and NewRatio bug. Since your new-space is no way near being one tenth of the -Jmx=9G. The bug includes a workaround (NewSize in absolute size).

Another flag that might be very important for you is CMSInitiatingOccupancyFraction. It is set at 92% in java6 and was 68% in java5. If the old-space grows larger the CMS threadpool will start to do their work. If you have CPU to spend, it is no danger to have a live-set that is above the initiating fraction.

It would be nice if you had included the GC stats after you fixed the memory paging problem.