Arch Linux

Please read this before reporting a bug:
https://wiki.archlinux.org/title/Bug_reporting_guidelines

Do NOT report bugs when a package is just outdated, or it is in the AUR. Use the 'flag out of date' link on the package page, or the Mailing List.

REPEAT: Do NOT report bugs for outdated packages!
Tasklist

FS#11422 - enable mod_mem_cache when using trac causes apache to crash

Attached to Project: Arch Linux
Opened by Alper Kanat (T-u-N-i-X) - Sunday, 07 September 2008, 23:50 GMT
Last edited by Jan de Groot (JGC) - Wednesday, 10 June 2009, 09:15 GMT
Task Type Bug Report
Category Packages: Extra
Status Closed
Assigned To Douglas Soares de Andrade (dsa)
Architecture All
Severity Medium
Priority Normal
Reported Version None
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No

Details

Edit: changed title to better reflect the current understanding of the problem.

--Original Report--

All necessary information are detailed here: http://www.dscpl.com.au/wiki/ModPython/Articles/ExpatCausingApacheCrash

Here's the version information on my Arch Linux box:

[02:48] (tunix@raptiye ~)$ strings /usr/lib/libexpat.so.1.5.2 |grep expat_
expat_2.0.1

[02:49] (tunix@raptiye ~)$ python
Python 2.5.2 (r252:60911, Jul 8 2008, 21:11:16)
[GCC 4.3.2 20080626 (prerelease)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pyexpat
>>> pyexpat.version_info
(2, 0, 0)

Apache on my production server crashes immediately when I use Trac and some Django apps using sqlite3..
This task depends upon

Closed by  Jan de Groot (JGC)
Wednesday, 10 June 2009, 09:15 GMT
Reason for closing:  Deferred
Additional comments about closing:  No response for 6 months, please reopen if this is still an issue.
Comment by Roman Kyrylych (Romashka) - Tuesday, 09 September 2008, 20:28 GMT
looks like pyexpat needs to be updated to use the latest expat version.
@ Alper: you haven't indicated which package contains pyexpat, so...
@ Allan: I'm assigning to you as python maintainer ;)
Comment by Alper Kanat (T-u-N-i-X) - Tuesday, 09 September 2008, 20:45 GMT
pyexpat is included within the python package :)
Comment by Allan McRae (Allan) - Wednesday, 10 September 2008, 06:34 GMT
Can you try building python with this PKGBUILD + patch? You will require the other files from ABS.

It should make python use the system expat library and my quick test with "pyexpat.version_info" looks good but I don't have apache + mod_python setup anywhere to test.
   PKGBUILD (2.5 KiB)
   internal-expat.patch (1.3 KiB)
Comment by Alper Kanat (T-u-N-i-X) - Wednesday, 10 September 2008, 11:16 GMT
as far as i see, python and strings shows the same version now.. but i still get

[Wed Sep 10 14:15:39 2008] [notice] child pid 23962 exit signal Segmentation fault (11)

errors when i try to reach a mod_python page despite i've restarted apache.. :S
Comment by Allan McRae (Allan) - Wednesday, 10 September 2008, 12:18 GMT
Perhaps this is a sqlite3 library version issue rather that an expat issue. However, I have check python, php, mod_python and the all seem to be linked to the system library. Any chance you can try to confirm it is indeed an expat issue and not a sqlite issue? Can you try removing modules from your httpd.conf and see if you can limit this further?
Comment by Alper Kanat (T-u-N-i-X) - Wednesday, 10 September 2008, 21:34 GMT
i've just added some part of the apache log... it gives an exception about mod_python.. hope it gives information..
   error.log (52.3 KiB)
Comment by Allan McRae (Allan) - Thursday, 11 September 2008, 03:12 GMT
Looks like a sqlite3 version mismatch to me... Can you tell me exactly what modules you load in your httpd.conf so I can figure out what the clash is?
Comment by Allan McRae (Allan) - Thursday, 11 September 2008, 03:16 GMT
Adding Pierre and dsa to assignees. I currently guessing this is a apache + php + mod_python clash of some variety...
Comment by Alper Kanat (T-u-N-i-X) - Thursday, 11 September 2008, 13:21 GMT
here is my httpd.conf (http://rafb.net/p/isJdp882.html)..

i'm not using php btw.. generally i have problem on trac and some django apps that use sqlite3 backend.. i can use those apps with other db engines..
Comment by Allan McRae (Allan) - Monday, 15 September 2008, 00:29 GMT
Can you put the http.conf as an attachment. The URL you provided seems to no longer work.

From what I saw earlier, you load a lot of modules. Can you try disabling various modules until you figure out what the clash is?
Comment by Alper Kanat (T-u-N-i-X) - Monday, 15 September 2008, 07:43 GMT
here is my httpd.conf.. i can't remove some modules because this is my production server..
   httpd.conf (16.4 KiB)
Comment by Tim Flink (trflink) - Sunday, 05 October 2008, 20:08 GMT
I found the same problem when I tried to get trac running with mod_python. At first, the expat versions didn't match. They did match after rebuilding the python package using the above fix.

Since httpd was still having the same problems, I started disabling modules in my httpd.conf until I stopped getting the segmentation fault messages. I found that if I disabled mod_mem_cache, trac worked without any problems. I re-enabled all other modules, and trac still works. My other php based app does, too (using mod_php).

I attached my current httpd.conf and my imported conf for trac to this post.
   httpd.conf_current (16.6 KiB)
   trac_video.conf (0.2 KiB)
Comment by Allan McRae (Allan) - Saturday, 18 October 2008, 01:48 GMT
@ Alper - can you confirm if removing mod_mem_cache fixes this for you?
Comment by Allan McRae (Allan) - Sunday, 19 October 2008, 04:26 GMT
Are you two using the SQL back-end for trac? If so, can you try this PKGBUILD for python-pysqlite? It may do nothing but I am running out of ideas...
   PKGBUILD (1 KiB)
Comment by Allan McRae (Allan) - Sunday, 19 October 2008, 06:13 GMT
@ Tim: Now you have found a work-around, can you also confirm whether the expat library difference has any effect at all?
Comment by Alper Kanat (T-u-N-i-X) - Monday, 20 October 2008, 00:01 GMT
Sorry, but I changed my production and test servers to nginx and don't have any Apache installed.. But glad that someone found the module that caused the problem..
Comment by Tim Flink (trflink) - Friday, 31 October 2008, 02:42 GMT
Sorry for the delay. I've been busy as of late and haven't made the time to try your fix.

I built and installed python-pysqlite using that PKGBUILD, re-enabled mod_mem_cache and trac causes a segfault again.

I re-disabled mod_mem_cache and installed python from core. Trac seems to be working fine. I checked the versions as listed in the original issue and found the same mismatch (2.0.1 in apache, 2.0.0 in pyexpat).
Comment by Allan McRae (Allan) - Friday, 31 October 2008, 02:50 GMT
Thanks, so this is definitely not and expat/pyexpat problem. Rather something used for mod_mem_cache and trac is causing problems...
Comment by Glenn Matthys (RedShift) - Friday, 05 December 2008, 21:19 GMT
What's the status of this issue?
Comment by Allan McRae (Allan) - Wednesday, 24 December 2008, 16:01 GMT
Even though this was established not to be the problem, the python package now links to the internal expat library.
Comment by Gerardo Exequiel Pozzi (djgera) - Saturday, 06 June 2009, 23:01 GMT
what is the status of this issue? can be closed this task?

Loading...