child pid # exit signal segmentation fault(11)

[Milind]

I am close to getting Apache perfect. But when I try to login into my site, it redirects me back to the index page[due to my redirection,I think]. But the main issue that I see in the error_log file, is the Segmentation fault.

[Sun Nov 18 17:20:46.608034 2012] [core:notice] [pid 6021:tid 140296226637568] AH00052: child pid 6022 exit signal Segmentation fault (11)

I checked for multiple versions of Python. I just have Python2.7 installed. No mod_python module is configured on my system.

Also, I checked whether it was happening due to pyexpat. It passes that test too. I referenced this link : http://code.google.com/p/modwsgi/wiki/IssuesWithExpatLibrary

I am pretty stuck here. Help, please.

Thanks,

Milind.

[Milind]

[UPDATE] : 

I am sorry. I forgot to mention my versions. I should have appended my httpd.conf file too.

I am running Apache 2.4, WSGI 3.4, and Python 2.7 on Ubuntu 12.10 Desktop.

My httpd.conf file looks something like this[only relevant parts]

WSGIDaemonProcess tindo user=ubuntu group=ubuntu processes=5 threads=1                                                                             

WSGIProcessGroup tindo                                                                                                                             

WSGIApplicationGroup %{GLOBAL}

WSGIRestrictStdin Off

WSGIRestrictStdout Off

From my crazy debugging, what I gather is that the first two lines might be the cause. But if I remove them, I get the NotImplementedError - gevent usable only from single thread. gevent seems to go for toss.

Any help is greatly appreciated.

Thanks,

Milind.

[Graham Dumpleton]

Try adding:

  WSGIApplicationGroup %{GLOBAL}

You may be using a Python module with a C extension component which will not work in a sub interpreter.

Otherwise there are various other shared libraries that can conflict if you are using mod_php in same Apache.

Graham

--
You received this message because you are subscribed to the Google Groups "modwsgi" group.
To view this discussion on the web visit https://groups.google.com/d/msg/modwsgi/-/EUTo-fYR2awJ.
To post to this group, send email to mod...@googlegroups.com.
To unsubscribe from this group, send email to modwsgi+u...@googlegroups.com.
For more options, visit this group at http://groups.google.com/group/modwsgi?hl=en.

[Graham Dumpleton]

Since you are already setting WSGIApplicationGroup, if you aren't using mod_php either, then read:

http://code.google.com/p/modwsgi/wiki/DebuggingTechniques#Debugging_Crashes_With_GDB

and see if can get a stack trace.

BTW, you don't need:

WSGIRestrictStdin Off

WSGIRestrictStdout Off

That is default for mod_wsgi 3.0+.

Graham

--

You received this message because you are subscribed to the Google Groups "modwsgi" group.

To view this discussion on the web visit https://groups.google.com/d/msg/modwsgi/-/2hnCBxAF1OIJ.

[Milind Utsav]

But that is already added in my configuration file. Please see my second post.

And even no mod_php module is configured.

--
Milind Utsav,

Software Developer,

Teritree Technologies Pvt. Ltd.

Contact : milind....@gmail.com

              +91-9742565861

[Milind Utsav]

Okay. Will remove those lines. And will check this link and post to you the trace.

Thanks,

Milind.

[Milind]

It sounds weird but switching the WSGI process from daemon mode to debug mode resolved the issue.

Now I have some new problems.

Are there any known issues with session management in Apache and mod_wsgi? Because my session is lost immediately after I log in.

Do I need to configure something for the session/cookies?

On Monday, November 19, 2012 1:55:40 PM UTC+5:30, Milind wrote:

[Graham Dumpleton]

If by debug mode you mean running Apache in single process mode, don't do that.

Change configuration to 1 daemon process and 1 daemon thread. Attach gdb to the process ID of that daemon process and then fire off the request.

If you are loosing sessions, sounds like you are using an in memory session database rather than a separate database. Being in memory, each daemon process will have a separate copy.

Graham

--

You received this message because you are subscribed to the Google Groups "modwsgi" group.

To view this discussion on the web visit https://groups.google.com/d/msg/modwsgi/-/Tf0ckFB82nkJ.

[Milind Utsav]

My configuration files lines are:

WSGIDaemonProcess debug thread=1

WSGIProcessGroup debug

Should I change them?

And I am using a separate database.

[Graham Dumpleton]

Try mod_wsgi 3.5 since you are using Apache 2.4. You may be hitting the issue fixed in it.

http://code.google.com/p/modwsgi/wiki/ChangesInVersion0305

Graham

[Milind Utsav]

It seems Apache isn't able to access my cache database. I am using python-memcached-1.4.8.

Any hint on why this may be happening?

[Graham Dumpleton]

Did you resolve the prior problem by trying development version of 3.5?

Is this new issue connected to prior problem or new?

More information about the error you are getting in Apache error logs or web application reporting is needed to determine how you are connecting to memcache and thus what problem could be.

Do determine though whether your system has SELinux enabled. That can place restrictions on what Apache processes can do.

Graham