[Zope] zope stops responding

[Sours, Kevin]

My experience is that increasing the number of threads past 4 does
absolutely nothing to assist performance.   Multi threads will help with
the occasional long running request, but if its more than occasional
then the thread list will eventually clog up no matter how many threads
you have (and the more threads you have, the more they fight over the
processor).  The server sounds beefy, but since Zope is only going to be
using one of those four cores, that might be deceptive.
Kevin

-----Original Message-----
From: zope-bounces+ksours=carsdirect.com at zope.org
[mailto:zope-bounces+ksours=carsdirect.com at zope.org] On Behalf Of Peter
Bengtsson
Sent: Thursday, July 03, 2008 9:19 AM
To: Garry Saddington
Cc: zope list user
Subject: Re: [Zope] zope stops responding

Yes, couldn't agree more with kevin. DeadlockDebugger is crucial. It
won't change anything other than that you'll have information about what
really needs to change.
As an intermediate solution you can start to increase the number of Zope
threads from 4 to 6 or 8 and see if that kills the CPU of your beefy
server. Too many threads can hurt performance especially when working
with badly coded external connectors that selfishly hook itself to the
python GIL too much.
A lightweight alternative to DeadlockDebugger is the table at the bottom
of the Debug Information page in Control_Panel. If any of the dates in
the first column in that table shows times longer than a second you have
a problem with those requests.

Peter

2008/7/3 Garry Saddington <garry at schoolteachers.co.uk>:
> Following a hard disk crash 2 weeks ago we have installed Zope onto a 
> new server and all was fine until yesterday morning when Zope stopped 
> responding and required a restart to get it working. It did the same
at 3-30pm today.
> We are using Zope 2.9.0 on Centos 5.1 on a quad Zeon server with 4gb. 
> Ram. At the moment the server is in quite heavy use with teachers 
> trying to write reports for a deadline tomorrow. These are sent to a
Postgres DB via psycopg.
> There is nothing in Z2.log or event.log to point me to the problem. I 
> am therefore asking for advice on the sorts of things that can cause 
> Zope to stop responding and whether there is anything we can do to 
> mitigate against such an event.
> Thanks and regards
> Garry
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--
Peter Bengtsson,
work www.fry-it.com
home www.peterbe.com
hobby www.issuetrackerproduct.com
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