Follow the instructions below to set up the Basic Failover Architecture as described in Best Practices for using Elastic IPs and Availability Zones. This setup has a production deployment where all of the instances are running in the same availability zone. This is the most affordable failover architecture on EC2 because data transferred between instances in the same availability zone is always free. A backup (clone) deployment is unactivated, but is ready to be launched into the us-east-1b availability zone. If there is a failure in us-east-1a, you must manually launch the backup deployment. As a safety feature you cannot automate the launching of a deployment. Remember, deployments are free. You can create and configure as many deployments as you want and you only have the pay for usage time if those instances are ever launched.
Once your production deployment is running as expected, make a duplicate of the production deployment by clicking the the Clone button at the deployment level (Manage -> Deployments). Notice that in this setup, all of the instances are in the same availability zone (us-east-1a).
Rename the cloned deployment and call it "Backup."
The next step is modify the backup deployment so that it launches the new instances into a different availability zone (us-east-1b). Other than changing the availability zone, everything else should remain unchanged.
Click on an instance's nickname and click Edit.
Select us-east-1b from the Availability Zone dropdown menu and click Save.
Repeat this process for each instance in the backup deployment.
Check to make sure that your two frontends are using the same Elastic IPs as the production deployment and that the "Associate IP at launch?" box is checked.
Congratulations! You now have a backup deployment that is properly configured to launch into a different availability zone for failover situations. All you have to do is click the "start all" link to launch all the new instances in the deployment.
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