What does Percentage of Java Heap Used under GC Monitor show?
I want to keep a track of Java heap size and threads.
Vaibhav --> % of Java Heap Used shows = Java Heap Used \ Total Java Heap assigned to that JVM instance.
You can keep a track of java heap usage % metric or 'heap in use'
Regarding - 'I want to keep a track of Java Heap size used by particular service'
You cannot track heap usage per service (I am assuming you are referring webservice or SOA call) but you can track heap usage for that JVM instance.
But what could be done is, you can stop all other services and test for an individual service and track your heap utilization.
Hope it helps.