Re: [Zope] Re: RedHat blows up? (another post follow up)
FuBuJo wrote at 2008-3-14 19:38 +: ... The behavior we found is that the python process running as the Zeo Client eventually takes up a large amount of resident memory (1.5 Gig or so), load average gets high (1.5 or so), and the end users start experiencing a very 'slow' experience. Does your system start swapping? In this case, you need to take urgent counter measures: * provide more RAM * check your configuration that affect memory consumption. The temporary storage hosting the sessions is often misconfigured. If you put large amounts of data in your sessions, this may be a considerable memory hog. Maybe, you need to make your ZODB caches smaller or reduce the number of concurrent threads. * check whether your application contains memory leaks. Unfortunately, this is not easy. Even when traffic is removed from the box - you still get a large response time (10s). This is Linux kernel 2.6.18-8.el5xen. Python sits on top of the C runtime memory allocation -- and this allocation does not support compaction. This means that the memory used in your program is likely to be scattered all over the process address space. Therefore, even with small load, you may face large response times when your system is unable to hold the (usally large) working set in memory. -- Dieter ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
[Zope] Re: RedHat blows up? (another post follow up)
Sorry I haven't been handling the system administration (I just 'code' the pages), and truthfully we tried it for about 3 weeks - and now are switching back. But certainly that isn't enough time to really root cause determine anything definitive. The behavior we found is that the python process running as the Zeo Client eventually takes up a large amount of resident memory (1.5 Gig or so), load average gets high (1.5 or so), and the end users start experiencing a very 'slow' experience. Even when traffic is removed from the box - you still get a large response time (10s). This is Linux kernel 2.6.18-8.el5xen. This is actually the issue we are having on FreeBSD (version 5.3) but the resident memory and load remains 1/2 of the above - and when traffic is removed from the box - you can then get a reasonable response ( 10s). I know it's not very scientific. We have a 'support agreement' with RH, so we are heading that way. But because the existing ZEO Server runs FreeBSD - and we are having performance issues, we figured to put everything back to the same OS while we try to figure out the performance part. When we investigate migrating from FreeBSD to RH for real - I'll certainly update this list if any of our findings would be of interest to anyone else. ___ Zope maillist - Zope@zope.org http://mail.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope-dev )
