Upgrade a server on an AWS EC2 instance with minimum risk and downtime

When you need to upgrade an application on an AWS EC2 instance with minimum downtime, there are many options.

Upgrade an EC2 instance

1. Stop the application, so users don’t make more changes,
2. Create a backup of the database (snapshot of the RDS instance),
3. Create a backup of the server (backup image of the EC2 instance),
4. Upgrade the application on the server,
5. Start the application,
6. Test the new version of the application.

In case the upgrade fails, or the post-upgrade test fails

1. Stop the application,
2. If you use RightScale to launch servers:
   1. stop the RightLink service on the failed server to prevent RightScale auto terminating the restored server
      (When RightScale finds a new identical server instance, it automatically shuts it down to avoid multiple instances with the same identifier.)
   2. Terminate the failed server
3. Stop the failed server,
4. Restore the database from the pre-upgrade backup with a new name,
5. Restore the server instance from the pre-upgrade backup,
6. Start the restored server,
7. Change the database address in the application’s config file to point to the restored database,
8. Start the application,
9. Test the restored version of the application.

To make the backup image of the AWS EC2 instance

1. Open the AWS console and navigate to EC2, Running instances
2. Find the server instance you want to backup
3. Right-click the row of the instance and select Image, Create Image
   
   
4. Name the image and click the Create Image button
   
5. Save the image Id from the popup