How does apache runs a application when a request comes in?

[Norah Jones]

Hi, 

I have a python web application running on apache2 deployed with `mod_wsgi`. The application has a thread continuously running. This thread is a ZeroMQ thread and listening to a port in loop. The application is not maintaining session. Now if I open the browser and sends a request to the apache server the data is accepted for the first time. Now when second time I send the request It shows Internal server error. When I checked the error log file for traceback,  It shows the ZMQError:- The address already in use. 

Does apache reloads the application on each request sent from the  browser since so that the ZeroMQ thread is being created everytime and being assigned the port but since the port has already been assigned it shows error....

Thanks,
Norah Jones