[mod_python] Session Hanging Problems

David Lenwell dlenwell at gmail.com
Mon Nov 26 14:21:31 EST 2007

yeah .. its very broken for me too .. What I am working on is my own  
session handler.. I don't feel that mysql is a valid replacement  
because it puts unnecessary load on your database server.

We are debating on open sourcing the code I am working on. if I win  
the argument that open source can be good for us then I will  
contribute my code to the project.

On Nov 26, 2007, at 10:55 AM, David Janes wrote:

> All I can say is "we too" -- we're using FileSession. We have not been
> able to come up with a cure, though we've minimized use of sessions
> which brings the frequency down significantly.
> Regards, etc...
> David
> On Nov 26, 2007 1:39 PM, Harish Agarwal <harish at octopart.com> wrote:
>> I'm using session handling with ModPython 3.3.1.  Originally I was
>> using DbmSession and have since transitioned to a custom MySQL  
>> Session
>> handler.  With both session types, however, I've noticed that session
>> initialization intermittently hangs (not forever, but takes as long  
>> as
>> four minutes to complete), at a low-ish (a handful of times every
>> hour, while receiving, say, on order of a thousand or so requests
>> every hour) frequency which seems to scale with the amount of traffic
>> we're receiving.  I had read that long DbmSession cleanups can cause
>> problems, which is why I transitioned to the MySQL system, which  
>> takes
>> < 1 second to complete, but I'm still noticing the long session init
>> times.
>> I put some debugging statements into the code and it seems to be
>> related to session locking.  In particular, it is this function call
>> in the lock method of the BaseSession class:
>> _apache._global_lock(self._req.server, self._sid)
>> which is taking some time to complete. I'm not familiar with
>> _apache._global_lock (is it used to apply a mutex lock to the
>> session?) and am having trouble finding information describing its
>> usage - but it seems likely that this is the root cause.  In the past
>> I've had problems with session locking but have since transitioned  
>> the
>> code to ensure that only one session is created per request, as such:
>> if not hasattr(req,'session'):
>>             req.session = Session.MySQLSession(req)
>> Can anyone tell me if this kind of behavior is normal or is  
>> indicative
>> of some common configuration or coding error?  Any help would be
>> greatly appreciated.
>> Thanks,
>> -Harish
>> _______________________________________________
>> Mod_python mailing list
>> Mod_python at modpython.org
>> http://mailman.modpython.org/mailman/listinfo/mod_python
> -- 
> David Janes
> Founder, BlogMatrix
> http://www.blogmatrix.com
> http://blogmatrix.blogmatrix.com
> _______________________________________________
> Mod_python mailing list
> Mod_python at modpython.org
> http://mailman.modpython.org/mailman/listinfo/mod_python

More information about the Mod_python mailing list