[Catalyst] Re: memory usage of mod_perl process

[Jeffrey Ng]

On 2/10/07, Tony Losey <tlosey at 3sixtygroup.com> wrote:
>
> On Fri February 9 2007 12:53 pm, Jeffrey Ng wrote:
> > On 2/9/07, Oliver Gorwits <oliver.gorwits at oucs.ox.ac.uk> wrote:
> > > Jeffrey Ng wrote:
> > > > I am the coworker of Fayland who posted the topic "memory usage of
> > > > mod_perl process".
> > > >
> > > > Our company has invested quite some time on migrating our perl code
> to
> > > > catalyst (more than half year of time by 7 programmers). However, I
> am
> > > > starting to worry that moving to catalyst is causing too much
> overhead
> > > > for our processes and thus severely slowing down our site.
> > >
> > > Take a good, hard look at what's coming out of your web servers.
> Install
> > > a Squid farm in front of the servers and let them cache anything
> > > suitable...
> >
> > yes we are thinking about that now. however, we are not sure how to
> update
> > the cache we we want to refresh the page. i guess we will adjust the
> http
> > header when we want to flush it? how does squid know if our page is
> > refreshed when it has already cached our page though?...
> >
>
> You can call the PURGE command on squid. You must allow this in the conf
> and
> put in place the proper acl to allow it. I believe you can call squid with
> the following options to force a purge of the cache of a given page.
>
> -m PURGE http://mywebsite.com/index.html
>
> We are not using catalyst in production yet so we don't have squid running
> in
> front of any catalyst apps. We do however have it running in front of some
> python/zope/plone sites. There are plugins that handle the purging
> directly
> for us. We just provide the url to purge to a method that handles the
> purge
> when needed.


right! i just googled and found
http://search.cpan.org/~sock/Net-Squid-Purge-0.1/
that cpan module should be able to purge the cached.

> letting Apache fork just to serve an image can be really damaging to
> >
> > > performance. Double check the HTTP headers on all outgoing pages
> include
> > > proper caching instructions for Squid so it'll work properly.
> >
> > yah, i know that. our catalyst apache servers are only for serving
> dynamic
> > pages. however, there are some ajax javascript files we have to host on
> the
> > exact same subdomain to work. i still feel that those javascript files
> are
> > wasting our apache resources. for ajax javascript like that, how should
> i
> > redirect the load to other servers while maintaining the same subdomain
> in
> > the location bar? i tried to use mod_rewrite, and seems like its even
> > slower than serving the file itself!
> >
> > Even whole store-front pages from Catalyst sites can usually be cached
> >
> > > well, because users don't have state at that point, and perhaps most
> > > hits are to your homepage (so remember to let Squid know your homepage
> > > is cacheable, in the headers).
> > >
> > > Remember mod_perl can be quite leaky as well, so kill off the child
> > > processes after they've served a few requests. Oh, and switch off
> > > hyperthreading if you have dual P4/Xeon boxes, and use PreFork MPM.
> > >
> > > There's more info in the slides from this LPW talk:
> > >
> > >
> > >
> http://london.pm.org/lpw/talks/2006/dave_hodgkinson-mod_perl_server_farm_
> > >architecture_done_right.pdf
> > >
> > > HTH,
> > >
> > > oliver.
> > >
> > >
> > > _______________________________________________
> > > List: Catalyst at lists.rawmode.org
> > > Listinfo: http://lists.rawmode.org/mailman/listinfo/catalyst
> > > Searchable archive:
> > > http://www.mail-archive.com/catalyst@lists.rawmode.org/
> > > Dev site: http://dev.catalyst.perl.org/
>
> _______________________________________________
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>



-- =

Jeffrey Ng
CEO, Zorpia.com
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