The Geek’s Blog

Segmentation Faults with eAccelerator and PHP 5.2.4

The first thing I did when moving to a dedicated virtual earlier this year was install a php opcode cache so the site would run at maximum speed all the time.

After consulting with most of my friends I ended up settling on XCache (although I don't exactly remember why), and I've had really good luck with it for months. Haven't had a single issue…

Because of the intense load the massive increase in readers has caused, and especially after introducing the forums, I decided to start looking for more options to speed up the server… so I turned to eAccelerator, which is not just an opcode cache but also an optimizer as well.

Everything seemed to be running well, and it even required a bit less memory than XCache, until I noticed that the WordPress MU site was down for more than 18 hours.

tail /var/log/http/error_log

[Tue Sep 25 22:36:08 2007] [notice] child pid 1615 exit signal Segmentation fault (11)
[Tue Sep 25 22:36:08 2007] [notice] child pid 7493 exit signal Segmentation fault (11)
[Tue Sep 25 22:36:08 2007] [notice] child pid 7494 exit signal Segmentation fault (11)

Crap!

So I've switched back to trusty XCache, and the problems stopped entirely. I'm not sure why the combination of Wordpress MU, eAccelerator and PHP 5.2.4 caused this issue for me, but maybe it's happened to you as well. If so, let me know.

This article was written on 09/27/07 and tagged with: Programming

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Comments (6)

1. October 10, 2007 1:34 pm
   Mitchell

   Thanks! This saved me a lot of time. eAccelerator apparently causes a seg fault when you (wrongly) try to require / include a class that was already required / included from a different location. Turning off eAccelerator allowed PHP to spit the error out on the screen.

2. October 10, 2007 1:36 pm
   The Geek

   Ah, that could have been the same problem I was having.

   Glad I could help! XCache has been rock solid, I don't think I'll switch again.

3. October 30, 2007 12:24 pm
   Toby Johnson

   Another thanks for the post. After noticing segfaults when I upgraded 5.2.3 to 5.2.4 I Googled "php 5.2.4 segmentation fault" and yours was near the top. I was always a little skeptical of eAccelerator but now I've installed XCache as well and it seems to be rock solid and fast!

4. October 30, 2007 12:34 pm
   The Geek

   Excellent, I'm glad this helped more than one person!

5. December 8, 2007 5:16 am
   james

   actually, i am getting segfault error, on Xcache.

   i have centos 5 w/ quad core on 2gb ram.

   i set the xcache.size to be 256mb and count to 4. and var_mem to 80mb

   can someone help me?

   did i set the cache size too high or something?

6. December 25, 2007 3:01 pm
   Piku

   Have you tried APC