[horde] Apache running Horde segfaults

[Daniel A. Ramaley]

Hello. I have been testing a Horde Imp webmail server for some time. 
Yesterday it finally went live, and the amount of traffic the server 
had to deal with increased by a couple orders of magnitude. Since then 
there has been a major problem. After running fine for awhile (where 
"awhile" is on the order of an hour and a half), the server will start 
returning empty pages. When this happens, Apache's error_log gets 
filled with lines like this:

[Tue Apr 04 08:07:06 2006] [notice] child pid 9954 exit signal 
Segmentation fault (11)

We are using a PostgreSQL database. It continually writes messages to 
its log (whether there is a problem or not) that look like:

Apr  4 08:23:17 sun12 postgres[10281]: [1-1] LOG:  unexpected EOF on 
client connection

At one time i was having a problem with PostgreSQL not accepting enough 
client connections; right now it is set to "max_connections = 256". I 
believe the relevant line in Apache's configuration is "MaxClients 128" 
which is clearly less than PostgreSQL's limit so it shouldn't be a 
problem anymore.

Has anyone seen a problem like this? How did you fix it?

The server is a Sun v40z, which is a dual Opteron box with 2 GB RAM. It 
is running Red Hat Enterprise AS 4, with these versions of the Horde 
software and other components:
  Horde 3.1.1
  Imp 4.1
  Ingo 1.1
  Kronolith 2.1
  Passwd 3.0
  Turba 2.1
The Apache version is 2.0.52, with PHP 4.3.9 and PostgreSQL 7.4.8. All 
the server runs is the web server and database; the Imap server it 
connects to is on a different machine. We are also using ldap address 
books, but they again are on a different machine. The Horde server has 
plenty of CPU (about 70% idle when it is getting hit hardest) and RAM 
(over half of the RAM is just being used by Linux for caching).

------------------------------------------------------------------------
Dan Ramaley                            Dial Center 118, Drake University
Network Programmer/Analyst             2407 Carpenter Ave
+1 515 271-4540                        Des Moines IA 50311 USA