Java memory usage/repair

Question

We are using a java application which is based on RMI.When we run the application the memory usage keep on increasing even though the the application is ideal stage.We are mainly using Vector and hash map data structure.how to minimize the java memory usage/repair memory leakage?

Thanks in advance

• Martijn Verburg: You need to do some root cause analysis of where your memory leak is coming from. What JDK are you using?
• Petro Semeniuk: Try take memory snapshots with JProfiler (or any other memory profiler) and compare them. You'll clearly see where memory is going.
• Selva: I am using j2sdk1.4.2_18
• Dan Breslau: How are you measuring memory usage? Are you looking at the process (through tools such as ps or the Windows Task Manager), or are you looking at Java heap usage?
• Selva: Using Windows Task Manager,is it right way?how to view the java heap usage?

Answer 1

If you can't upgrade your JDK version, I suggest testing your application on another machine (real or virtual) with the latest 1.6 JDK, and then use the built in jvisualvm which is a really great tool for diagnosing problems like this.

Answer 2

I'd start with trying to understand Java's memory model.

Here's a stackoverflow question (858250) with lots of links explaining.

Answer 3

Since you're using 1.4.2, and you can't use jmap or visualvm, I'd suggest running your Java process with:

-XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath="foo.out"

and after it runs out of memory, open foo.out with HPjmeter. This should help you identify the objects ballooning in your application.