Tuning JVM (GC) for high responsive server application

Question

I am running an application server on Linux 64bit with 8 core CPUs and 6 GB memory.

The server must be highly responsive.

After some inspection I found that

Answer 1

For high responsive server application, I think you want to see the major GC happens less frequently. Here is the list of parameters would help.

-XX:+CMSParallelRemarkEnabled
-XX:+CMSScavengeBeforeRemark
-XX:+UseCMSInitiatingOccupancyOnly
-XX:CMSInitiatingOccupancyFraction=50
-XX:CMSWaitDuration=300000
-XX:GCTimeRatio=40

Larger heap size may not help on low pause, as long as your app doesn't run out of memory.

Larger NewSize and MaxNewSize would help on throughput, may not help on low pause. If you choose to take this approach, you may consider give GC threads more execution time by setting -XX:GCTimeRatio lower. The point is to remember to take a holistic when tuning JVM.