IIS (Win2012) on EC2 with auto scaling

Question

We are looking at moving around 100 websites that we have on a dedicated web server, from our current hosting company; and host these sites on a EC2 Windows 2012 server.

I've looked at the type of EC2 instances available. Am I better going for a m1.small (or t1.micro with auto scaling). With regards auto scaling, how does it work, if I upload a file to the master instance, when are the other instances updated ? Is it when the instances are auto scaled again ?

Also, I will be needing to host a mail enable (mail server) application. Any thoughts on best practice for this ? Am I better off hosting 1 server for everything, or splitting it across instances...?

Answer 1

When you are working with EC2, you need to start thinking about how your applications are designed and deployed differently.

Autoscaling works best when your instances follow shared nothing architecture. The instances themselves should never store persistent data. They should also be able to be automatically set up at launch.

Some applications are not designed to work in this environment. They require local file storage, or other issues.

You probably wont be using micro instances. They are mostly designed for very specific low utilization workloads.

You can run a mail server on ec2, but you will have to use an Elastic IP and whitelist the instances sending mail. By default, EC2 instances are on the spamhaus block list.