Date: Mon, 21 Jun 1999 07:28:40 -0400 (EDT)
From: Ryan Bloom <rbb@raleigh.ibm.com>
To: new-httpd@apache.org
Subject: Re: some questions about threaded apache
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 <Pine.LNX.4.04.9906210724520.17675-100000@chosondo.raleigh.ibm.com>
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> I'm still experimenting with the threaded Apache, and I'm noticing some
> odd behaviour.  I was wondering if someone could clarify things for me.
> 
> MinSpareServers 20
> MaxSpareServers 40
> StartServers 10
> MaxClients 23
> ThreadsPerChild 64
> 
> Now, I assumed that MinSpareServers would be the number of processes, each
> with a variable number of threads.  So 1 and 2 would seem to be
> reasonable.  However, when I use those values I get (according to
> server-status) 0 idle servers, and I do see a noticeably slower connection
> (although once connected I'm quick, presumably because I'm reusing my
> connection).  When I increased those values to 20/40, it never kills any
> threads, so I always have a total of 1454 threads (I chose those numbers
> because I've limited NR_TASKS to 1500 per user).  This doesn't really pose
> much of a problem to me, but I would assume that other people would like
> the number of threads/processes to decrease when load dies down :-)

In the current implementation, threads don't die on their own.  The only
time we spawn new threads, or kill old ones, is when a whole new process
is created, or a whole procesw goes away.  This may change in the future,
but spawning and killing threads is something that most pthread libraries
don't do well.

The 0 idle servers may be due to how we are computing the number of idle
servers.  Currently, it is based on the total number of threads in the
server.  

And it's REALLY good to know the threaded Apache is able to handle a real
world load better than the process based one. :)

Ryan
_______________________________________________________________________
Ryan Bloom		rbb@raleigh.ibm.com
4205 S Miami Blvd	
RTP, NC 27709		It's a beautiful sight to see good dancers 
			doing simple steps.  It's a painful sight to
			see beginners doing complicated patterns.