Finding Memory Leaks using JProbe

How to prevent Memory Leaks :

We can prevent memory leaks by watching for some common problems. Collection classes, such as hash tables and vectors, are common places to find the cause of a memory leak. This is particularly true if the class has been declared static and exists for the life of the application.

JProbe Memory

The JProbe Memory analysis tool enables you to:

·         Identify and resolve memory allocation issues. (For eg. when in your code if you are doing explicity memory allocation, then the tool would ensure that you are freeing up the memory also.)

·         Identify the underlying root cause of memory leaks that can lead to instability and out-of-memory system crashes.

·         Identify the underlying root cause of excessive garbage collection activity which can slow down the system performance. (For example when memory is allocated and is not freed up, the garbage collection would need to be run often)

JProbe Memory Debugger helps you improve memory usage in your Java application by identifying loitering objects and excessively allocated objects.

A loitering object is an object that is determined to be reachable by the garbage collector, but is no longer in use by your application. So if your program will never use an object again, but you fail to remove the reference to the object, the object will remain, or loiter, in memory indefinitely. This problem is commonly referred to as ?unintentional object retention? or loitering objects. Additionally, loitering objects can compound memory usage problems if that object is acting as an anchor to other objects that would otherwise be marked as unreachable by the garbage collector and therefore removed.

If your program creates an excessive number of objects, the Java heap will become larger, and garbage collection will take longer because there are more objects to evaluate. A simple example would be a method that allocates a new temporary object during each iteration of a loop, even though the object is never reused and is no longer required when the loop terminates.

1                   Steps to find Memory Leaks

Step by step to find the memory leaks using jprobe

Download latest version of Jprobe from http://wwwin-apptools.cisco.com/tools/jprobe/

Set up license server as -

Select the server to run under jprobe and to generate the jprobe script