Java Tuning

To enable verbose GC output use the follwing java options when starting the JVM:

-verbose:gc

The output looks like this (and can vary slightly from different version of the JVM):

 
[GC 46336K->3775K(129664K), 0.2158256 secs]

This line represents a partial GC, as can been seen by the first part of the line:

[GC

if this GC had been a full GC, the first part of the output would be:

[Full GC

The other fields are as follows:

To enable remote JMX for Java for the SUN JVM, add these options to your JAVA_OPTIONS settings:

-Dcom.sun.management.jmxremote.port=9999
-Dcom.sun.management.jmxremote.authenticate=false
-Dcom.sun.management.jmxremote.ssl=false"

This will allow you to connect to the JVM with such tools as JConsole.