Permanent Heap

Permanent heap memory is where the classes, methods, and similar data are stored. This is controlled by two settings: -XX:MaxPermSize is discussed in Changing the Value of MaxPermSize. The other setting is -XX:PermSize.

What it does

The -XX:PermSize option controls the section of the heap that is reserved for the permanent generation and holds all of the reflective data for the JVM.

Original value

By default, -XX:PermSize is set to 4096 mb.

Changing the Value

This size should only be increased to optimize the performance of applications that dynamically load and unload a lot of classes. Setting -XX:PermSize to a larger value eliminates the overhead of increasing this part of the heap.

Warning: TIBCO recommends that you do not change this value without consulting TIBCO Support.