Measuring time spent on GC in JVM

Question

Suppose I am testing a Java server application. I know how much time it takes to finish the test. Now I\'d like to know how much was spent on GC during that test. How can I

Answer 1

This performance metric is recorded by the JVM, and made accessible through JMX. For interactive monitoring, connect to the running JVM with JConsole, and in the "VM Summary" Tab it will say something like:

Garbage collector: Name = 'Copy', Collections = 26, Total time spent = 0.183 seconds Garbage collector: Name = 'MarkSweepCompact', Collections = 2, Total time spent = 0.168 seconds

You can also query JMX programatically.