On 8/7/06, Daniel A. Ramaley <daniel.ramaley@xxxxxxxxx> wrote:
Symptom 1:
After starting Apache during periods of high load the server appears to
run fine for awhile ("awhile" is highly variable but on the order of 90
minutes) then starts returning empty pages. When the empty pages start,
Apache's error_log gets filled with lines like this:
[Fri Aug 04 14:18:29 2006] [notice] child pid 16021 exit signal
Segmentation fault (11), possible coredump in /etc/httpd/core
These errors are very intermittent (occurring every few hours to every
few weeks) during periods of light load. I have had CoreDumpDirectory
defined for awhile and have amassed quite a collection of core files.
This is the first few lines of what gdb reports for one of the dumps:
(gdb) bt
#0 0x0000002a99ff2492 in preg_replace_impl (ht=Variable "ht" is not
available.)
at /usr/src/redhat/BUILD/php-4.3.9/ext/pcre/php_pcre.c:1154
#1 0x0000002a9a0ac255 in execute (op_array=0x552afe2798)
at /usr/src/redhat/BUILD/php-4.3.9/Zend/zend_execute.c:1640
#2 0x0000002a9a0a9386 in execute (op_array=0x552aff7fb8)
at /usr/src/redhat/BUILD/php-4.3.9/Zend/zend_execute.c:1684
#3 0x0000002a9a0a9386 in execute (op_array=0x552b0e26c8)
at /usr/src/redhat/BUILD/php-4.3.9/Zend/zend_execute.c:1684
#4 0x0000002a9a0a9386 in execute (op_array=0x552af80db8)
at /usr/src/redhat/BUILD/php-4.3.9/Zend/zend_execute.c:1684
That is clearly a programming error either in php or pcre. You might want to try php forums or the php bug database to see if you can find the solution.
Symptom 2: At other times messages about MaxClients show up. I don't believe the server is actually running out of processes to serve requests since even during the academic year when it is very busy requests are handled quickly enough that there are seldom more than a dozen or two in progress at any moment. [Fri Aug 04 02:30:02 2006] [error] server reached MaxClients setting, consider raising the MaxClients setting
119 processes closing connections
2 processes reading requests
4 processes sending replies
3 processes waiting for connections
This problem seems unrelated to the first. It does seem unusual to have all those processes in the closing phase. When you look at the full server-status output, do many of the lines comes from the same IP? This would be an indication of a (deliberate or accidental) denial of service attack. Otherwise, you could look at commonality between the types of requests they are processing. Joshua. --------------------------------------------------------------------- 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@xxxxxxxxxxxxxxxx " from the digest: users-digest-unsubscribe@xxxxxxxxxxxxxxxx For additional commands, e-mail: users-help@xxxxxxxxxxxxxxxx
|