[Zope] Performance problems after upgrade

[Jean-Francois.Doyon at CCRS.NRCan.gc.ca]

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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