Re: Help me in setting up MaxClients

Mark Watts <m.watts@xxxxxxxxxxxxxxxx> · Mon, 25 Jan 2010 16:36:17 +0000

On Mon, 2010-01-25 at 09:44 -0500, Jeff Trawick wrote:
> On Mon, Jan 25, 2010 at 8:56 AM, Vikrama Sanjeeva
> <viki.sanjeeva@xxxxxxxxx> wrote:
> > Hello All,
> >
> > This is regarding production servers. Recently Apache server hit MaxClient
> > settings; resulting in crash of sites. However, sites was back to normal
> > after restarting Apache.
> 
> The expected symptom is that Apache is unresponsive to additional
> requests until some of the child processes finish what they're working
> on.
> 
> Restarting Apache without increasing MaxClients isn't helpful; if it
> is a hard restart it trashes the current connections.
> 
> > I read about MaxClient settings and increase it from 200 to 250 (as I read
> > somewhere that 256 is a limit).
> 
> Run apachectl -V to see the limit; it should be in the tens of thousands.

Umm, does it?

# apachectl -V
Server version: Apache/2.2.13 (Unix)
Server built:   Sep 17 2009 15:37:59
Server's Module Magic Number: 20051115:23
Server loaded:  APR 1.3.3, APR-Util 1.3.4
Compiled using: APR 1.3.3, APR-Util 1.2.7
Architecture:   32-bit
Server MPM:     Worker
  threaded:     yes (fixed thread count)
    forked:     yes (variable process count)
Server compiled with....
 -D APACHE_MPM_DIR="server/mpm/worker"
 -D APR_HAS_SENDFILE
 -D APR_HAS_MMAP
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D APR_USE_SYSVSEM_SERIALIZE
 -D APR_USE_PTHREAD_SERIALIZE
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
 -D APR_HAS_OTHER_CHILD
 -D AP_HAVE_RELIABLE_PIPED_LOGS
 -D DYNAMIC_MODULE_LIMIT=128
 -D HTTPD_ROOT="/etc/httpd"
 -D SUEXEC_BIN="/usr/sbin/suexec"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="conf/mime.types"
 -D SERVER_CONFIG_FILE="conf/httpd.conf"

# apachectl -V
Server version: Apache/2.2.14 (Unix)
Server built:   Dec  3 2009 10:25:53
Server's Module Magic Number: 20051115:23
Server loaded:  APR 1.3.9, APR-Util 1.3.9
Compiled using: APR 1.3.9, APR-Util 1.3.9
Architecture:   32-bit
Server MPM:     Prefork
  threaded:     no
    forked:     yes (variable process count)
Server compiled with....
 -D APACHE_MPM_DIR="server/mpm/prefork"
 -D APR_HAS_SENDFILE
 -D APR_HAS_MMAP
 -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
 -D APR_USE_SYSVSEM_SERIALIZE
 -D APR_USE_PTHREAD_SERIALIZE
 -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
 -D APR_HAS_OTHER_CHILD
 -D AP_HAVE_RELIABLE_PIPED_LOGS
 -D DYNAMIC_MODULE_LIMIT=128
 -D HTTPD_ROOT="/etc/httpd"
 -D SUEXEC_BIN="/usr/sbin/suexec"
 -D DEFAULT_PIDLOG="logs/httpd.pid"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_LOCKFILE="logs/accept.lock"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="conf/mime.types"
 -D SERVER_CONFIG_FILE="conf/httpd.conf"

-- 
Mark Watts BSc RHCE MBCS
Senior Systems Engineer, Managed Services Manpower
www.QinetiQ.com
QinetiQ - Delivering customer-focused solutions
GPG Key: http://www.linux-corner.info/mwatts.gpg