[mod_python] handler module loading/execution phases

Graham Dumpleton graham.dumpleton at gmail.com
Tue Oct 13 18:27:04 EDT 2009

I don't know then. The code looks reasonable. I can only suggest you
add more and more debug, including your own logging at module scope to
track when imported.

Also ensure you read the 'import_module()' section of:


If still stumped, perhaps look at using a WSGI framework and mod_wsgi instead.


2009/10/14 Alessandro de Manzano <demanzano at playstos.com>:
> Graham Dumpleton wrote:
>> Apache/mod_python on UNIX is multi process and therefore requests
>> don't necessarily go back to the same process. Also, if using worker
>> MPM, that code isn't thread safe and so technically multiple threads
>> updating global variable at same time could not see it being
>> incremented as you expect.
> yes, I know, but eventually I should see a non-zero value, sooner or later.
> I tested about 100 requests and they reported always dummy=0
> Apache currently spawns about 10 processes max so I'm quite sure the same
> unix process do process more than one http request, do invoke more than one
> time my handler function.
>> It is also possible for Apache processes to be recycled both at the
>> whim of Apache, but also explicitly if MaxRequestsPerChild is set to
>> be non zero in Apache configuration files.
>> BTW, if you have PythonDebug set to On, then the error logs should
>> display messages about when mod_python loads or reloads mod_python
>> handler module files.
> it shows the module is "correctly" (re)loaded only once after file modified
> (for every apache process, of course), so it seems to me that already-loaded
> processes should maintain the value, it should simply invoke again the
> handler.
> But it seems instead if totally re-evaluate (!?) the module.
> Actually my dummy example was to understand apache+modpython inner workings,
> because in the real program I had to instantiate an "heavy" class (which
> connects to external DB, opens files, etc.) and I hoped to avoid to do it
> for each and every single request...
> thanks for answers
> bye
> Ale

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