Recently Amazon EC2 announced that they were going to support Windows Server 2008 instances.
The experience with GoGrid has been rocky to say the least and most recently the MyGSI’s shortcomings confirmed that the service was not able to meet our applications requirements for using instances on demand.
Which brings me to this post. After 14 months with GoGrid I have just recently completed a migration of all applications and databases to Amazon EC2 and thought I would outline the steps I took.
Creating New Instances
Before you start you will need to create your new instances in Amazon EC2. I have covered this previously in another post.
When you set up the firewall it is important that you open Port 1433 for traffic coming from your previous web server in GoGrid. Or if you want you can even create a temporary VPN between your GoGrid web server and EC2 database server using Amazon Virtual Private Cloud. This is an important step in ensuring minimal downtime.
At this point you’ll want to create CNAMES for the Amazon instance and add these bindings to IIS so that you can test all your applications before the DNS changes take affect.
Transferring Files & Data
The way I transferred the files was via Amazon S3, download speeds between EC2 and S3 are very fast. If you don’t have an S3 account yet just go to http://aws.amazon.com/s3/ and click the “Sign Up” button.
Once these are done all you need to do is backup any databases then zip the databases and files up and upload to a bucket in S3.
Once Uploaded you can download from within your EC2 instance, unzip and change any configuration values.
If you can put an indicator on one of your web pages which will help you to see that the DNS has gone through.
Test, Test, Test
Goes without saying but once you have all files and databases setup on your new instance you will want to perform some serious testing.
Don’t forget those Folder Permissions.
Making the DNS Change
Whether or not you have downtime depends entirely on the nature of your application. For a standard content managed website your data and files aren’t going to change that often so you should have plenty of time.
If you have a highly active system with lot’s of database writes then the downtime will be limited to the Backup, Restore process of your database. This was the case for me.
Load a temporary message onto your app advising users of the scheduled maintenance and make sure no users can log in.
Backup any data and files on your live GoGrid instance that may have changed after the last backup.
Upload to S3.
Download an unzip on EC2 instance. Restore any files and databases.
Change any Database Connection Strings on your live instance to point to your new EC2 instance on port 1433.
Update the DNS to point to your new server.
Once the DNS change has taken full affect (wait a week) you can terminate your GoGrid instances and enjoy the goodness of Amazon EC2.
I will still be using GoGrid as a failover provider in case of any outage on Amazon EC2.