[Zope] Performance problems after upgrade

[Dennis Allison]

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?