New EC2 API released (2008-02-01): Elastic IPs and User Selectable Kernels


Amazon has released the latest version of the Elastic Compute Cloud (EC2) API: 2008-02-01.

This release includes a number of new features, two of which are very interesting: Elastic IP Addresses and User Selectable Kernels.

Elastic IP Addresses

Elastic IP Addresses allow you to allocate static IP addresses to your AWS account, and programmatically associate these addresses with your EC2 instances. This feature should make it feasible to map DNS names directly to EC2 instances without using dynamic DNS naming services. If your instance dies or if you plan to terminate it, you can simply start another instance and reassign the elastic IP address to it.

Reserving (allocating) yourself an IP address costs 1¢ per hour that the address is not associated with a running instance, and there is no charge for addresses that are associated with an instance. By default there is a limit of 5 IP addresses per account, but this limit can be increased upon request.

User Selectable Kernels

User Selectable Kernels allow you to user alternative Linux kernels to the default one provided by Amazon. To make this possible, the EC2 environment will contain two new kinds of images in addition to the Amazon Machine Images (AMIs) we are familiar with: Amazon Kernel Images (AKIs) and Amazon RAM disk Images (ARIs). The new API and bundling tools allow you to mix-and-match machine images with kernel and RAM disk images, though you have to be careful doing this as not all the images will work well together.

Note that you cannot create and load your own kernels. Instead, you must choose from a set of kernels made available by Amazon and “selected vendors”. Hopefully a future API version will make it possible for anyone to create their own customized kernel images.

Availability Zones

In addition to these two features, the new API also includes support for Availability Zones that allow you to specify the location(s) where your EC2 instances will run. Eventually the list of locations may include multiple regions (ie. countries or geographical areas) but currently all EC2 data centers are located in the United States. There are a number of zones or locations within the US region, for example: us-east-1a, us-east-1b, us-east-1c. This feature will help to distribute, or concentrate, your EC2 instances depending on the requirements of your application.

Tags: AWS