One of my favorite features of EC2 is the ability to create virtual machine templates and re-use them to create fresh copies of a virtual machine. This is great but things rapidly get onerous when you’re trying to duplicate infrastructure. Amazon recently unveiled a new service called AWS CloudFormation. There are currently many Amazon cloud offerings available: S3, Elastic Block Storage, EC2, and Elastic Beanstalk are just a few. AWS CloudFormation is more than just another member of the family: it ties them all together. The idea behind AWS CloudFormation is to make it easy to create a collection of AWS resources and then deploy them the same way every time. AWS CloudFormation is similar to using Chef recipes to deploy software configuration. In this case we’re deploying an entire infrastructure stack to multiple virtual machines via a recipe. We can design our infrastructure on AWS. As our business grows we will be able to quickly and easily duplicate crucial parts of our infrastructure. AWS CloudFormation makes it simpler to manage all of your infrastructure. Deployments of new infrastructure become a matter of pushing out a template. If there are problems with a deployment, the changes can be rolled back and a clean up happens to make sure you aren’t charged for anything that you’re not using.
In a traditional IT department, there is a design, purchase, deploy cycle that can potentially take a very long time. In previous jobs, we’ve had to design the infrastructure based on obscure internal capacity planning metrics. Once we’d made predictions/guesses about our future growth, we would then wait for weeks or even months to acquire new hardware. Once we had the hardware, it might even sit around for days or weeks before we were finally able to provision, configure, and deploy the servers on the network. That doesn’t even include deploying our own software on the server. On the flip side of that coin, by combining AWS CloudFormation plus Chef/Puppet, we can now push a new batch of servers out into the cloud in a matter of minutes and have them running in a few hours. Our software can be automatically installed and configured with Chef or Puppet. While we still need to write templates, once we’ve created and tested our templates for specific purposes (blog, database, community site, whatever), we’re able to fully automate deployments.
AWS CloudFormation can also ease the pain of scaling out our applications. Typically when we scale out an application, we’re starting from a monolithic application stack. All of the assets in our stack have been scaled up to a point where it’s cost prohibitive to keep scaling. At this point, we’d examine each layer of our application and determine the best place to add caching or scale out to use multiple application or database servers. As we keep scaling our stack, we need to add more load balancers, caching servers, and database read slaves until we’ve exhausted our options and have to revisit our application design. Rather than engaging in the exercise of attempting to scale all of our customers at once, why don’t we start out by sharding all application resources at the customer level? While this increases the overall cost of operating our business, it makes it easy to scale elastically in response to a changing customer base. The busiest customers will get larger servers and increased performance that meets their needs. It also becomes possible to locate our data close to your customer in one of several Amazon zones. For businesses offering software as a service, this makes a great deal of sense. They get an easy way to monitor usage per customer and can scale appropriately within known guidelines and with well known costs.
AWS CloudFormation makes it possible to provision and deploy infrastructure using a set of templates. When you combine CloudFormation with Chef orPuppet, it becomes very easy to deploy infrastructure and then deploy additional configuration changes on top of the infrastructure. Ultimately, AWS CloudFormation makes it easy to quickly and easily deploy new infrastructure in response to changes in load or customer demand. If you’re interested in some of the discussion around AWS CloudFormation, be sure to check out the Hacker News thread on the subject.