topic A process consumes memory constantly in Operating System - Linux

A process consumes memory constantly

John Guster — Tue, 06 Jul 2010 15:49:54 GMT

java.bin process "RES"(Resident size) of "top" command is increasing as time goes by, it never reaches a certain value. We have to reboot the system when all swap is exhausted. Is this an indication of memory leak? In the man page of top it says "RES" = CODE + DATA. One would think "RES" has to be a certain size, can not be grow unbounded. It is Red Hat Linux 4 system. The Java is IBM's.
Any idea will be appreciated.

Re: A process consumes memory constantly

S.N.S — Tue, 06 Jul 2010 17:37:59 GMT

Hi John,

Is Oracle running on RHEL?
Any specific messages?

The Expert here could help better...

SNS

Re: A process consumes memory constantly

John Guster — Tue, 06 Jul 2010 17:57:19 GMT

Below is part of the top output:

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
7498 appadm 18 0 2209m 391m 3756 S 0.0 19.3 0:02.30 java.bin
Note that RES=391m, it is keeping growing to the point system has to be rebooted. There is no oracle, not any error while it is growning.

Re: A process consumes memory constantly

Steven E. Protter — Tue, 06 Jul 2010 18:29:59 GMT

Shalom,

http://www.hpux.ws/?p=8

There is a Linux version or rather Linux code in that shell script.

It will help you identify the process, which you already seemed to have done.

Normally this is fixed by patching the application.

SEP

Re: A process consumes memory constantly

Ivan Ferreira — Wed, 07 Jul 2010 13:13:33 GMT

>>> Is this an indication of memory leak?

Nornally yes, you can use pmap to identify how much "private" (anonymous) memory the process is using.

A good document can be found here:

http://blogs.sun.com/nickstephen/entry/solaris_measuring_the_memory_overhead

Re: A process consumes memory constantly

John Guster — Thu, 08 Jul 2010 18:48:25 GMT

It seems it is used for the heap which has max limit set. Before it reaches the max, it will appear as memory leaking because it is growning and growning...thanks for your ideas.

Re: A process consumes memory constantly

Dennis Handly — Sun, 11 Jul 2010 00:36:33 GMT

>it will appear as memory leaking because it is growing and growing

Java has a different definition of memory leak because it has garbage collection.