Restarting a Django application running on Apache + mod_python

Question

I'm running a Django app on Apache + mod_python. When I make some changes to the code, sometimes they have effect immediately, other times they don't, until I restart Apache. However I don't really want to do that since it's a production server running other stuff too. Is there some other way to force that?

Just to make it clear, since I see some people get it wrong, I'm talking about a production environment. For development I'm using Django's development server, of course.

Answer 1

If possible, you should switch to mod_wsgi. This is now the recommended way to serve Django anyway, and is much more efficient in terms of memory and server resources.

In mod_wsgi, each site has a .wsgi file associated with it. To restart a site, just touch the relevant file, and only that code will be reloaded.

Answer 2

As others have suggested, use mod_wsgi instead. To get the ability for automatic reloading, through touching the WSGI script file, or through a monitor that looks for code changes, you must be using daemon mode on UNIX. A slight of hand can be used to achieve same on Windows when using embedded mode. All the details can be found in:

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

Answer 3

You can reduce number of connections to 1 by setting "MaxRequestsPerChild 1" in your httpd.conf file. But do it only on test server, not production.

or

If you don't want to kill existing connections and still restart apache you can restart it "gracefully" by performing "apache2ctl gracefully" - all existing connections will be allowed to complete.

Answer 4

Use a test server included in Django. (like ./manage.py runserver 0.0.0.0:8080) It will do most things you would need during development. The only drawback is that it cannot handle simultaneous requests with multi-threading.

I've heard that there is a trick that setting Apache's max instances to 1 so that every code change is reflected immediately--but because you said you're running other services, so this may not be your case.