Programming Amazon Web Services

Chapter 8. SQS: Simple Queue Service

Amazon’s Simple Queue Service (SQS) provides reliable storage and delivery of messages between any clients or computers with access to the Internet. It allows message senders and recipients to interact without having to communicate directly with each other and without requiring that either side be always available or connected to the network.

SQS combines the key advantages of a conventional messaging architecture—loosely-coupled and fault-tolerant communication—with a reliable and flexible distributed infrastructure that stores messages redundantly over multiple data centers. Because SQS is accessible to clients on any platform that can send and receive HTTP requests, the service makes it possible to build distributed applications with truly heterogeneous components using a range of platforms and development languages.

Note

As this book went to press, Amazon Web Services released a new version of the SQS service API: 2008-01-01. This new API includes an updated pricing model that is intended to make the service cheaper for most users, however it also includes significant changes that are not compatible with previous API versions or the third-party libraries and tools we use in this book.

The previous APIs will remain available until May 6, 2009, after when all SQS users must migrate to the 2008-01-01 version. In this book we describe the older 2007-05-01 API and we will not discuss the new API in depth. For more information about the benefits ...