[Zope] strange performance problem

[Dennis Allison]

Yeah...  I use Pound as a front-end and Pound does *not* work under 
RH9.  I always blamed the NPTL but in a conversation on the Pound list
this morning, it occured to me that the problem may lie with threads
getting split across processors.   I'm going to run an experiment today.

	-d



On Tue, 23 Mar 2004 Jean-Francois.Doyon at CCRS.NRCan.gc.ca wrote:

> Dennis,
> 
> This is in direct correlation with the check interval suggestion I made.
> 
> In your search, you will find that on SMTP systems, tweaking the check
> interval can help things, precisely because of the GIL.
> 
> I set it to zero because I had the spare CPU power, and trying to fully
> understand/benchmark python's behavior on SMTP seemed like too much work :P
> 
> J.F.
> 
> -----Original Message-----
> From: zope-bounces at zope.org [mailto:zope-bounces at zope.org]On Behalf Of
> Dennis Allison
> Sent: Tuesday, March 23, 2004 10:39 AM
> To: Chris Withers
> Cc: zope at zope.org
> Subject: Re: [Zope] strange performance problem
> 
> 
> Thanks.  I'll review the archives.  -d
> 
> On Tue, 23 Mar 2004, Chris Withers wrote:
> 
> > Dennis Allison wrote:
> > 
> > > While it's possible, the scheduler is pretty good at maintaining
> processor
> > > affinity without intervention.  I have *never* seen anything which would
> > > suggest that is a problem.  This is happening on an unloaded system when
> > > processor affinity issues should be hard to trigger.
> > 
> > Okay, but I have lots of memories of reading about problems with Python's
> Global 
> > Interpretter Lock and lightly loaded multi-processor machines.
> > 
> > The mailinglist archives may give more of a clue.
> > 
> > One thing you could try is to get a ZEO storage server up and running,
> then run 
> > up 4 or 5 ZEO clients, but each with only one thread. Then you just need
> to 
> > figure out how to round-robin them so they all appear through one port...
> > 
> > cheers,
> > 
> > Chris
> > 
> > -- 
> > Simplistix - Content Management, Zope & Python Consulting
> >             - http://www.simplistix.co.uk
> > 
> 
> 
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