[Zope] Performance problems after upgrade

[Dennis Allison]

Thanks.  Your experience is encouraging.  I still syspect the GIL may be
one of the culprits, but I may wait a bit before pointing fingers.  In the
background is a move to a 2.6 kernel with cpu_affinity etc etc.
I have done some profiling but the results are difficult to interpret.

Andy Dustman suggested I move up to a later MySQL adaptor which I will do
this evening.  And the quest continues...



On Wed, 25 Aug 2004 Jean-Francois.Doyon at CCRS.NRCan.gc.ca wrote:

> I don't use Mysql ... And I use Zope 2.7.2 with Python 2.3.3.
> 
> But I have the RH7.3 with the same kernel ... On a 4 CPU machine.
> 
> I DID tweak the interpreter lock timing to try and improve performance ...
> (Related to the GIL).
> 
> I used the guidlines from:
> 
> http://www.zope.org/Members/glpb/solaris/report_ps
> 
> I have to admit I never truly benchmarked it, I just noticed it seemed to
> perform better.
> 
> I'm not really spending too much time on it, as my focus now is to use
> single CPU machines
> for all things Zope/Python.
> 
> I've never noticed any unexplained "bursty" performance, we i do have it,
> it's usually due to traffic,
> bursts of requests, and so on ...  Today for instance I've been averaging 10
> hits/sec and the site
> is nice and fast.
> 
> With a 2 cpu machine you're less likely to feel the effects of the GIL issue
> ... In your case
> I don't know what I'd suspect ... You might have to figure out exactly which
> requests/threads
> run for too long and figure out what they have in common. (Which you can
> normally figure out just
> by looking at the debugging screen).
> 
> If worst comes to worst, do some profiling?
> 
> J.F.
> 
> -----Original Message-----
> From: zope-bounces at zope.org [mailto:zope-bounces at zope.org]On Behalf Of
> Dennis Allison
> Sent: August 25, 2004 3:21 PM
> To: zope at zope.org
> Subject: [Zope] Performance problems after upgrade
> 
> 
> 
> I upgraded from mysql-3.23.56-1.9 to mysql--4.0.20-0 using the mysql.org
> RPMS, from Zope 2.6.2b3 (Python 2.1.3) to Zope 2.6.4 (Python 2.3.4) under
> Linux RH7.3 with kernel 2.4.20-28.7.  Host is a dual Athalon processor
> with 4GB of memory, 3ware RAID (configured as RAID 10) and not much else.
> 
> Performance is way down from the earlier configuration with "bursty"
> slowdowns. There is some evidence that it is somehow related to
> redirection in the Zope application, but we have not been able to locate
> the problem.
> 
> Has anyone else experienced this sort of problem?  Pointers and
> suggestions would be appreciated.
> 
> It is possible that the behavior could arise from a different kernel (and
> different scheduler) and the GIL (Global Interpreter Lock).  We have
> several years experience running Zope on a dual processor machine
> on RH7.3 without observable GIL problems, but it is a possible source of
> the problem.  Does anyone have a suggestion as to how to determine if that
> is the case?
> 
> 
> 
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