How can I improve performance of 'Old Gen' Garbage collection
I have a big, active JVM with 20 applications.
The heap is 30GB and the eden:old ratio is default 1:2
The issue is the time spent on Full GC.
In the best case the FGC will take 50 seconds. During busy periods 180 seconds is the average. So far I have the best results using the 'UseParallelOldGC flag but I'm trying to find other ways to reduce the FGC time.
For comparison I am running another machine with a same size heap but only 1 application. It's able to recover almost twice as much memory in half the time.