title: Amazon EC2 high availability
body: <h3>Following the scenario:</h3>
  <p>There is a service that runs 24/7 and a downtime is extremely expensive. This service is deployed on Amazon EC2. I am aware to the importance of deploying the application on two different availability zones and even in two different regions in order to prevent single points of failure. But...</p>
  <p>My question is whether there are any <strong>additional configuration</strong> issues that may affect the redundancy of an application. I mean also to wrong configuration (for example wrong configuration of the DNS that will make it fail in case of a fail over).</p>
  <p>Just to make sure I am clear - I am trying to create a list of validations that should be tested in order to ensure the redundancy of an application deployed on EC2.</p>
  <p>Thank you all!</p>