title: Start Django config app only once when using multiple Gunicorn workers
body: <p>I'm using :<br></p>
  
  <ul>
  <li>python 3.6 </li>
  <li>django==2.1.1</li>
  <li>gunicorn==19.9.0</li>
  </ul>
  
  <p>i have done the following:</p>
  
  <ul>
  <li>created a django project called <code>api</code> </li>
  <li>created an <code>apiapp</code> (an app in my project) </li>
  </ul>
  
  <p>and i have this code in api_app's <code>apps.py</code> :</p>
  
  <pre><code>from django.apps import AppConfig
  from api import settings
  
  class ApiappConfig(AppConfig):
      name = 'apiapp'
      verbose_name = "random_name"
  
      def ready(self):
          self.job()
  
  
      @classmethod
      def job(cls):
          ### doing whatever here for example :
          print(settings.SHARED_VARIABLE)
  </code></pre>
  
  <p>and the following in api_app's <code>__init__.py</code>:</p>
  
  <pre><code>import os
  default_app_config = 'apiapp.apps.ApiappConfig'
  </code></pre>
  
  <p>i'm creating an API so i am required to use multiple workers when deploying:</p>
  
  <pre><code>gunicorn api.wsgi -w 10
  </code></pre>
  
  <p>now, my issue is that the function <code>job</code> which is called when the server is started, is getting called 10 times because i'm using 10 gunicorn workers, i would like to call it only once</p>
  
  <p>another thing that i would like to do is to have the 
  <code>settings.SHARED_VARIABLE</code> variable, shared between the different workers. this variable will be updated only by the worker that will launch the <code>app.py</code> on server start.</p>
  
  <p>Thank you ! </p>