PHPMaster.com: Amazon DynamoDB: Store PHP Sessions with Load Balancer
This tutorial will show you how to use Amazon DynamoDB as a storage facility for PHP sessions. This method becomes very useful when your applications take advantage of the Elastic Load Balancing and Autoscaling services. You will need Amazon AWS account enabled to use EC2, Elastic Load Balancer and DynamoDB as a prerequisite to play along the tutorial.
He starts with a description of what the elastic load balancing service is and how it autoscales. He shows how, based on this demo application, to use a custom PHP session handler that implements the Amazon SDK libraries to hook into the DynamoDB service. Also included are screenshots (and the steps that go with them) to configure the service itself.