We are receiving alerts from the Websphere Application Server 7.0.25 whenever heap memory reaches to 90% but Garbage Collection did not run at that moment. We monitor the memory and found that GC is running only after 99% of heap memory usage. The JVM parameters are set as:
Initial Heap Memory - 128MB
Max Heap Memory - 512MB.
Please suggest is there anyway, where GC starts after reaching 90% or less than that heap memory utilization.
Garbage collection is something totally delegated to the JVM implementation; JVM should do its best to keep the free heap space among min and max values. It sounds
strange that gc is run only with 99% heap usage. Sure to have installed latest PTF ? Sure not to have set any "strange" parameter for the JVM ?
If it's the case, you may open a PMR.