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From Jim Jagielski <...@jaguNET.com>
Subject Re: process model again...
Date Wed, 08 Apr 1998 15:56:50 GMT
Marc Slemko wrote:
> 
> On Wed, 8 Apr 1998, Jim Jagielski wrote:
> 
> > Dirk-Willem van Gulik wrote:
> > > 
> > > 
> > > > So I've been continuing with trying to figure out if the current
> > > > perform_idle_server_maintenance() code is right.  I'm now convinced that
> > > > we no longer need MinSpareServer, but can't give a good mathematical
> > > > reason for why.  It just doesn't seem necessary to keep many spare when
> > > > the server will exponentially spawn if a load presents itself.
> > > 
> > > Hmm, though the time needed to spawn a new child is short (and might be
> > > short compared to the actual handling) I would expect that this delay
> > > is in itself the reason for having MinSpareServer's ready.
> > > 
> > 
> > Hmmm... worse case, let's assume MinSpareServer is 5 and we all
> > of a sudden get hit by a bunch of requests such that we are 5 process
> > short. With MinSpareServer, Apache will be able to handle these
> > requests with "no" delay and then spawn extra processes "in the
> > background" as well. Without MinSpareServer, Apache could take
> > about 3 seconds to have enough processes to handle the
> > extra requests, so there's that delay... Most likely I buggered
> > something up in my assumptions, but that's how it looks to me :/
> 
> Yes, but the reason for that delay is not necessarily intrinsic to the
> process, just a side-effect of the current implementation.  Apache could
> spawn servers on demand a lot faster than it does.
> 

That's right... it is a function of how it's currently implemented, where
one second may or may not be a Good Value (I have no idea). Obviously,
then, a longer delay makes MinSpareServer more of a "latency
handler" than it would be if the idle-check were shorter.

-- 
===========================================================================
   Jim Jagielski   |||   jim@jaguNET.com   |||   http://www.jaguNET.com/
            "That's no ordinary rabbit... that's the most foul,
            cruel and bad-tempered rodent you ever laid eyes on"

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