mod_wsgi: multiple application invokations per request?

I'm using apache with mod_wsgi, and when I start apache and make a request, I see it make one invokation of the application. After a few minutes (the application gets reloaded), and now I see it make two invokations of the application per request. Why's that?

Also: is there any easy way to initialize resources (database pools, for example) with wsgi? I have the feeling it's complicated...

Here's my conf:

NameVirtualHost *:80

WSGIPythonPath /Users/blahblah/servercode/
WSGIPythonEggs /Users/blahblah/running/eggs/

<VirtualHost *:80>


    ErrorLog /Users/blahblah/running/error.log
    LogLevel debug
    CustomLog /Users/blahblah/ru开发者_运维百科nning/access.log combined
    ServerSignature On

    DocumentRoot /Users/blahblah/wsgi

    WSGIScriptAlias /mps.py /Users/blahblah/wsgi/wsgi_connector.wsgi

    <Directory /Users/blahblah/wsgi>
        Options Indexes FollowSymLinks
        AllowOverride All
        Order allow,deny
        Allow from all
    </Directory>

</VirtualHost>