Re: Apache intermittent crash - HELP!!!

[gary lim <garylkc@xxxxxxxxx>]

Hi Daniel,

After performance tuning of apache, the mem usage is now more managable. However, the apache still experience intermittent crash which we suspect is due to certain PHP module running in our joomla website.

top output
top - 04:58:52 up 160 days,  4:02,  1 user,  load average: 0.08, 0.04, 0.05
Tasks:  69 total,   2 running,  67 sleeping,   0 stopped,   0 zombie
Cpu(s):  1.9% us,  5.0% sy,  0.0% ni, 93.2% id,  0.0% wa,  0.0% hi,  0.0% si
Mem:    917652k total,   908144k used,     9508k free,    32660k buffers
Swap:  1048568k total,    37856k used,  1010712k free,   179480k cached


Model: Dell PowerEdge 850

CPU:Intel Pentium IV 3.0GHz / 2MB, 800MHz FSB
RAM: 2GB DDR-2 SDRAM 533MHz w/ ECC

Harddisk: 02 x SATA (7200RPM) HDD (non-RAID)


Apache Version
Server version: Apache/2.0.58
Server built:   Dec 12 2006 21:41:17

Server version: Apache/2.0.58
Server built:   Dec 12 2006 21:41:17
Server's Module Magic Number: 20020903:12
Server loaded:  APR 0.9.12, APR-UTIL 0.9.12
Compiled using: APR 0.9.12, APR-UTIL 0.9.12
Architecture:   32-bit
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 HTTPD_ROOT="/usr"
 -D SUEXEC_BIN="/usr/sbin/suexec2"
 -D DEFAULT_PIDLOG="/var/run/httpd.pid"
 -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
 -D DEFAULT_LOCKFILE="/var/run/accept.lock"
 -D DEFAULT_ERRORLOG="logs/error_log"
 -D AP_TYPES_CONFIG_FILE="/etc/apache2/mime.types"
 -D SERVER_CONFIG_FILE="/etc/apache2/httpd.conf"

Compiled in modules:
  core.c
  prefork.c
  http_core.c
  mod_so.c

On Thu, Dec 17, 2009 at 10:22 PM, Daniel Reinhardt <cryptodan@xxxxxxxxxxxxx> wrote:

From: gary lim

Sent: 17 December, 2009 5:05

To: users@xxxxxxxxxxxxxxxx

Subject: Re: Apache intermittent crash - HELP!!!

Hi daniel,

1. the intermittent crash happens even before we did any performance tuning of the apache.

2. the reason why we did the tuning is because we want to limit the apache memory usage which previously was due to apache using up all the swap mem causing the crash.

rgds

On Thu, Dec 17, 2009 at 12:42 PM, Daniel Reinhardt <cryptodan@xxxxxxxxxxxxx> wrote:

-->From: gary lim
-->Sent: 16 December, 2009 16:20
-->To: users@xxxxxxxxxxxxxxxx
-->Subject: Apache intermittent crash - HELP!!!
-->
-->
-->Dear all,

-->
-->1. I'm using Linux 2.6.16.29 and running on i686 Intel(R) Pentium(R) 4 CPU 3.00GHz GNU/Linux
-->2. The below info are my machine config and log output
-->3. Kindly advise how to resolve intermittent apache crash even after performance tuning

-->
-->apache2 error log

-->*** glibc detected *** /usr/sbin/apache2: double free or corruption (fasttop): 0x08b4faf0 ***
-->[Tue Dec 15 13:04:22 2009] [error] server reached MaxClients setting, consider raising the MaxClients setting
-->*** glibc detected *** /usr/sbin/apache2: double free or corruption (fasttop): 0x086a1170 ***
-->*** glibc detected *** /usr/sbin/apache2: double free or corruption (fasttop): 0x08b48c08 ***

Gary,

What version of glibc do you have?  The glibc detected could be causing this since its producing a dump code.  I would revert back to a default setup with your httpd.conf file, and just use the basics you need for your site to run.  If you get no crashes then its an issue with your performance tuning.

Thanks,
Daniel

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Gary,

 

If your application is using all of the SWAP memory maybe its time to rebuild the system with more swap space or upgrade the RAM.  Can you post the server specs for us?  I have never seen an application take full use of all the memory and all the allocated swap space.  You have hardware issues that need to be dealt with before attempting to solve the software ones.

 

When you list your system specs, can you also tell us if your Kernel has support for higher memory system configs?

 

Thanks,

Daniel