More mod_wsgi weirdness: process restarts on redirect

[rdmurray at bitdance.com]

Quoth Ron Garret <rNOSPAMon at flownet.com>:
> In article <mailman.8321.1233272610.3487.python-list at python.org>,
>  Joshua Kugler <joshua at joshuakugler.com> wrote:
> 
> > Ron Garret wrote:
> > > My question is: is this supposed to be happening?  Or is this an
> > > indication that something is wrong, and if so, what?
> > 
> > You are probably just hitting a different instance of Apache, thus the
> > different process ID.
> 
> Yep, that's what it turned out to be.  I thought I had a 
> WSGIDaemonProcess processes=1 directive in my config, but I had it in 
> the wrong place (a different vhost) so it wasn't actually active.
> 
> But that leaves me wondering why the redirect would reliably trigger 
> switching processes.  The reason I thought that I had the correct 
> configuration and only had one process is that when I reloaded the 
> non-redirected page I *always* got the same process ID.  How does 
> mod_wsgi decide which process  (and which thread for that matter) to use?

My WAG would be that when doing a refresh your client used a persistent
http connection, and thus talked again to the same Apache child, but when
it got a redirect it dropped the old connection and opened up a new one,
thus having a high probability of hitting a new child.  But that is,
as I say, a WAG.

--RDM