Chris Meller wrote:
> Hey Graham,
>
> Thanks for the reply and the link, it cleared up and confirmed some of the
> things I've been seeing and thinking.
>
> We've been running mod_python with Apache's mpm_prefork mainly because we
> run mod_php. The settings for mpm_prefork have been heavily tuned down to
> keep Apache in line, but each process slowly baloons to eventually take up
> to 15% of the RAM on our 512mb VPS. As a result we've had to keep the number
> of processes incredibly low to prevent them eventually eating our system
> alive.
>
> Several solutions have been proposed. Running Trac via mod_fcgid, switching
> to mpm_worker, and even running Trac as its own daemon and proxying Apache
> requests through to it... We've also talked about surrendering and
> outsourcing SVN and Trac hosting. At this point we have to do something,
> it's just a matter of picking a solution and doing it...
>
> I think the link you referenced says it all, but if you've got any more
> specific recommendations, please let us know. :)
Give Apache/mod_wsgi a go is the only other thing can suggest. Just
run Trac in mod_wsgi daemon mode as suggested in that blog post. The
default of a single process with 15 threads would be reasonable
starting point. Also set maximum-requests option to WSGIDaemonProcess
directive such that process is recycled every 1000 requests. For more
details see:
http://code.google.com/p/modwsgi/wiki/IntegrationWithTrac
Graham
> On Mon, Mar 30, 2009 at 5:11 AM, Graham Dumpleton <
> [email protected]> wrote:
>
> >
> >
> >
> > On Mar 30, 12:37 pm, Chris Meller <[email protected]> wrote:
> > > We're running Trac through mod_python, roughly following the instructions
> > athttp://trac.edgewall.org/wiki/TracInstall
> > >
> > > It seems to be a combination of mod_python being a resource hog
> >
> > Problems that people have with Apache/mod_python using a lot of
> > memory, are not because of mod_python, but because of how you have
> > configured Apache. Specifically, you have chosen the wrong MPM and/or
> > not changed the default MPM configuration settings to something more
> > appropriate for a fat Python web application. For an explanation see:
> >
> >
> > http://blog.dscpl.com.au/2009/03/load-spikes-and-excessive-memory-usage.html
> >
> > These days mod_python simply isn't the right tool for hosting the ever
> > increasing size of Python web applications unless you understand
> > properly how Apache works and how to tune it well.
> >
> > Graham
> >
> > > and Trac's
> > > MySQL support still being "experimental". If you take a look at the slow
> > > query log on the hp.o slice (it's logging non-indexed queries right now
> > > too), there are a crapload of queries relating to Trac. Looking at them,
> > > there are a bunch that just seem crazy too. They're either insanely
> > > brilliant or insanely crazy. I haven't looked into some of the queries
> > > enough to know which.
> > >
> > > For example:
> > >
> > > # u...@host: habari_trac[habari_trac] @ localhost []
> > > # Query_time: 0 Lock_time: 0 Rows_sent: 0 Rows_examined: 13520
> > > use habari_trac;
> > > SELECT rev FROM node_change WHERE CAST(rev AS signed) > 2828 AND
> > >
> > (path='branches/081011-errorhandling/htdocs/system/themes/charcoal/multiple
> > .php'
> > > OR path LIKE
> > >
> > 'branches//081011-errorhandling//htdocs//system//themes//charcoal//multiple
> > .php//%'
> > > ESCAPE '/' OR (path in
> > >
> > ('branches','branches/081011-errorhandling','branches/081011-errorhandling/
> > htdocs','branches/081011-errorhandling/htdocs/system','branches/081011-erro
> > rhandling/htdocs/system/themes','branches/081011-errorhandling/htdocs/syste
> > m/themes/charcoal','branches/081011-errorhandling/htdocs/system/themes/char
> > coal/multiple.php')
> > > and change_type='D')) ORDER BY CAST(rev AS signed) LIMIT 1;
> > >
> > > On Sun, Mar 29, 2009 at 9:19 PM, Sean Coates <[email protected]> wrote:
> > >
> > > > > Trac is always slow... it sucks. I would say any SVN slowness is
> > > > > probably as a result of this hook hitting Trac.
> > >
> > > > Do you have any actual evidence of this, or is this just anecdotal?
> > > > How are we running python? mod_python? fcgi? cgi?
> > >
> > > > S
> >
> > >
> >
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