title: How to make sure my event is handled by only one instance of my app?
body: <p>In our architecture we have a Redis server we use for caching and for publishing event.</p>
  
  <p>My problem is the following </p>
  
  <ul>
  <li>I have an message called "CustomerUpdate"  </li>
  <li>I have 1 application listening to this message </li>
  <li>3 instance (server) of this application are  being executed for scalability </li>
  <li>1 instance of the database is running</li>
  <li>One of the handler for this message will update the database</li>
  <li>Some other handler will erase memory cache or do something local to the instance</li>
  </ul>
  
  <p>Is there any pattern for making sure that the database is not updated by every instance of the application? </p>