Monitoring the VM Garbage Collection 
The VM function enables you to monitor the VM garbage collection ratio, released memory, and full garbage collection.
GC Ratio – shows the average proportion of total time used by the last full garbage collection.
Released Memory – shows the released memory per minute by the garbage collector when the garbage collection is running.
Full GC Duration – shows the duration of the last garbage collection.
Prerequisites
You have started SAP NetWeaver Administrator and use the AS Java Overview tool.
Procedure
To resolve the problems with the VM garbage collection, from the context menu of the functions, choose Check VM Parameters or Manage Sessions, accordingly.
Go to the Java System Properties or Session Manager applications.