Amazon and MongoDB work together to make sure you can run high performance, production ready MongoDB clusters on EC2.
White Paper: MongoDB on AWS
This white paper will help you understand one of the most popular NoSQL options available with the AWS cloud computing platform—the open source database MongoDB. We provide an overview of general best practices that apply to all major NoSQL options, and we examine important MongoDB implementation characteristics such as performance, durability, and security. We pay particular attention to identifying features that support scalability, high availability, and fault-tolerance.