reverse proxy vs. stand-alone

[Cliff Wells]

On Fri, 2009-05-15 at 18:55 +0400, Igor Sysoev wrote:
> On Fri, May 15, 2009 at 12:48:28AM -0700, Cliff Wells wrote:
> 
> > On Fri, 2009-05-15 at 09:19 +0400, Igor Sysoev wrote:
> > > On Thu, May 14, 2009 at 05:36:15PM -0700, Cliff Wells wrote:
> > > 
> > > > On Thu, 2009-05-14 at 20:24 -0400, jemari wrote:
> > > > > Hi everyone,
> > > > > 
> > > > > I am setting up a small VPS. My plan is to have nginx as a reverse
> > > > > proxy to apache2 (running with mod-php). All other static files will
> > > > > be served by nginx.
> > > > > 
> > > > > Does anyone know if there would be a significant difference in
> > > > > performance and/or stability if I removed apache, and have nginx use
> > > > > fcgi for php?
> > > > 
> > > > Yes, you'd save hundreds of megabytes of RAM by not using Apache, which
> > > > will undoubtedly affect performance in a positive fashion.
> > > 
> > > Would not these megabytes go to php/FastCGI ?
> > 
> > Not really.  PHP under FastCGI seems to use a lot less resources than
> > mod_php.   I assume this is because the number of threads is a constant
> > with PHP under FCGI.  
> > 
> > I converted a Joomla site from Apache/mod_php to Nginx/FastCGI and went
> > from constantly consuming the full 256MB (and crashing the VPS) to using
> > only around 20MB of RAM.
> 
> Have you tried to set
> 
> StartServers     20
> MinSpareServers  20
> MaxSpareServers  20
> MaxClients       20

StartServers       3
MinSpareServers    3
MaxSpareServers   10
ServerLimit      10
MaxClients       10
MaxRequestsPerChild  2000

I tried both prefork and worker MPM.

Apache and PHP would still exhaust the 256MB RAM in the VPS once a week
or so and force a restart of the entire VPS.   Someone suggested that
using FastCGI with Apache might help, but I never got around to trying
it before switching the site over to Nginx.

Cliff