Mailing-List: contact users-help@httpd.apache.org; run by ezmlm
Precedence: bulk
Reply-To: users@httpd.apache.org
Received-SPF: pass (athena.apache.org: domain of craig@animalhead.com
 designates 198.66.255.31 as permitted sender)
Message-Id: <EEE38B11-7434-444C-94A0-EB1C4434661E@animalhead.com>
From: craig@animalhead.com
To: users@httpd.apache.org
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Content-Transfer-Encoding: 7bit
Mime-Version: 1.0 (Apple Message framework v930.3)
Date: Mon, 5 Jan 2009 00:56:17 -0800
Subject: [users@httpd] ThreadsPerChild vs THR in top using Event MPM

Hi,

I'm running Apache2.2.11 with the Event MPM under FreeBSD 6.3, on
a site that's largely mod_perl2 driven.

ThreadsPerChild is specified as 25 in an include file of httpd.conf:
     MaxClients           250
     MinSpareThreads       25
     MaxSpareThreads      150
     ThreadsPerChild       25

The documentation of the Worker MPM (which is supposed to have the
same configuration characteristics as Event) states that each child
process creates (ThreadsPerChild) threads when it inits, and never  
changes
the number of threads.

But the THR column of the 'top' utility shows 11 threads per process.
Is 'top' just wrong, or is something constraining how many threads are
being created?

The only way I know to ask Apache about its threads configuration
is the Apache2::MPM->query facility.  Using this facility for all of
the values noted in the Apache2::Const documentation yields:

MPMQ_MAX_DAEMON_USED(1) = -1
MPMQ_IS_THREADED(2) = 1
MPMQ_IS_FORKED(3) = 2
MPMQ_HARD_LIMIT_DAEMONS(4) = 16
MPMQ_HARD_LIMIT_THREADS(5) = 64
MPMQ_MAX_THREADS(6) = 25
MPMQ_MIN_SPARE_DAEMONS(7) = 0
MPMQ_MIN_SPARE_THREADS(8) = 25
MPMQ_MAX_SPARE_DAEMONS(9) = 0
MPMQ_MAX_SPARE_THREADS(10) = 150
MPMQ_MAX_REQUESTS_DAEMON(11) = 0
MPMQ_MAX_DAEMONS(12) = 10

MPMQ_MAX_THREADS has the same value as ThreadsPerChild, but its name
suggests that this number is a maximum.  Perhaps this implies that this
number may not be created?

Help will be much appreciated,
craig
www.animalhead.com


---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
   "   from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org