A badly configured Java VM can affect the performance of your entire system.
The behaviour of the Java garbage collector can be an indication of configuration and performance problems, however in order to get this information you need to start your VM with some extra options:
Logging is activated with the "-verbose:gc" option and redirected to a file using the "-Xverbosegclog:< file >" option.
Verbose logging captures many types of GC events, including:
regular GC cycles
heap expansion and contraction
concurrent marking events
Verbose logs also show the approximate length of time many events take, the number of bytes processed (if applicable), and other relevant metrics.
For more information see the IBM Java performance page:
The Java Performance Advisor is an automated Java testing tool and can be downloaded from: