[Zope] strange performance problem

[Dennis Allison]

Thanks for the assist.   

Swap:  I doubt it, but it's worth checking.  It runs at 44MB or so at the
moment out of 2GB allocated.

RAM:  Currently I have 4GB installed using whatever RH 7.3 believes is the
right memory model--I believe they use the 1GB system, 3GB user model with
my resource configuration.

Threads: I currently am running 8 threads per Zope, but there are multiple
instances of Zope.  I rarely see more than four threads active.  CPU
utilization has occasional peaks, but typically is under 5% on both CPUs.

Check Interval:  I have not dorked with the check interval.  I'll try
dropping it. I'd guess it will improve responsiveness but not resolve this
problem.

Zope & Python:  The Python 2.1.3 and Zope 2.6.2b3 are not likely to be the
problem here. That's one of the stable configurations.  I plan to move to
Zope 2.6.4 and Python 2.3.3 when I feel I can do it safely on a production
system. I may even go to Zope 2.7 but there's greater risk moving a live
system which cannot accept downtime.

ZEO?: I don't currently use ZEO.  Should I be using it?

Thanks.   -d

On Mon, 22 Mar 2004 Jean-Francois.Doyon at CCRS.NRCan.gc.ca wrote:

> Dennis,
> 
> As far as resource problems go ... Did you check the swap ? Is it used, and
> if so by how much ?
> 
> I was experiencing the same thing, only it would stop responding for up to
> several minutes, sometimes even long enough
> that I was just not willing to wait, so I had to restart it.
> 
> I had 1GB of RAM, and the swap was holding 600-700K ... I surmised that
> maybe the waits occured when swapped out information
> had to be brought back or something ... So I added another GB of RAM, and
> now all problems have gone away.
> 
> If that's not it, I'd look at increasing your thread count, maybe all your
> threads get locked long enough for the users to notice, due
> to long running actions ...
> 
> The check interval could be looked at since you're on SMP.  Since I had lots
> of spare CPU cycles, I set it to 0 myself, and that makes
> Zope very very responsive if you can spare the CPU power ... it's great!
> 
> Python 2.3.1 and a beta zope also could be a problem, wasn't there
> issues/bugs with that ? Python 2.6.2 or 2.6.3 were officially support 2.1
> ... I successfully used it with 2.2 for a while, but could never get it to
> run with 2.3.1 (Wouldn't even compile !).  You might want to look into the
> 2.7/2.3.3 combo, it's been working very well for me as far as performance
> and stability.
> 
> Good luck !
> J.F.
> 
> -----Original Message-----
> From: zope-bounces at zope.org [mailto:zope-bounces at zope.org]On Behalf Of
> Dennis Allison
> Sent: Monday, March 22, 2004 4:44 AM
> To: zope at zope.org
> Subject: [Zope] strange performance problem
> 
> 
> This has the characteristics of a network problem, but it may be somewhere
> else.  Users report that the system just seems to stop responding for a
> few seconds, then recovers.  Of course, I've not been able to reproduce
> the problem nor isolate a command sequence that triggers it, but I am
> convinced that it's real.  This, BTW, happens on a lightly loaded machine
> with no apparent resource problems.
> 
> Any thoughts, pointers, or techniques to isolate the problem would be
> appreciated.   
> 
> Oh, yes, the environment..  Dual Athlon Barton Stepping CPUs AMD2600, Tyan
> Tiger Motherboard, 4GB memory, 4x120 3Ware RAID 10, ethernet feed.  RH7.3
> OS, Python 2.3.1, Zope 2.6.2b3.
> 
> 
> Any help appreciate.   -dra
> 
> 
> 
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