topic Re: memory leak with CSWS in Operating System - OpenVMS

memory leak with CSWS

Gregg Parmentier — Thu, 07 Sep 2006 15:36:25 GMT

Alphaserver 1000 5/300 512MB memory
OpenVMS V7.3-1
Tcpware V5.7-2
CSWS V2.0

Everything is stable until I start CSWS, then I start losing memory. I've determined that, if I periodically kill any APACHE$SWSxxxx processes numbered 5 and above, the memory leak slows, but does not go away. The more active the web hits, the faster the memory disappears.

Anyone have an idea?

Re: memory leak with CSWS

Richard Whalen — Thu, 07 Sep 2006 16:19:40 GMT

Can you clarify what you mean by a memory leak? Are you talking about non-paged pool consumption? Or process dynamic memory consumption?

Re: memory leak with CSWS

Gregg Parmentier — Fri, 08 Sep 2006 08:13:16 GMT

Hm, all I've been looking at is the physical memory usage. I'll disable my delaying tactics and get more specific information.

Re: memory leak with CSWS

Andy Bustamante — Fri, 08 Sep 2006 19:00:54 GMT

You need to review physical memory, free page list, modified page list and "in use" memory figures along with XFC stats. Free memory will drop when you do anything.

Getting Started with OpenVMS: A Guide for New Users by Michael D. Duffy can provide an introduction on memory use by OpenVMS.

Andy

Re: memory leak with CSWS

Volker Halle — Sat, 09 Sep 2006 01:27:11 GMT

Gregg,

OpenVMS is a virtual memory system and pyhsical memory is a shared resource, which OpenVMS tries to provide as needed to all components of the operating system requesting physical memory.

OpenVMS (including XFC) try it's best to automatically balance the available physical memory against the memory requests. There are certain system parameters and user quotas, which control these algorithms.

A 'memory leak' in this context, would show up as increasing workingset and/or virtual page or pagefile usage by individual processes, finally leading to EXQUOTA or INSVIRMEM errors for those processes.

Overall physical memory shortage on a system will result in heavy hard-paging and/or swapping.

Volker.

Re: memory leak with CSWS

Gregg Parmentier — Tue, 12 Sep 2006 15:06:45 GMT

Not really a memory leak, but thanks for all the information. For someone who's been using VMS for twenty years, and doing admin for ten, I sure do have some funny gaps in my knowledge.