Basic Queue Operations

The Simple Queue Service employs a simple interface that is easy to use and highly flexible. The following operations are provided:

• CreateQueue: Create queues for your own use, or to share with others.
• ConfigureQueue: Modify the properties of an existing queue.
• ListMyQueues: List your existing queues.
• DeleteQueue: Delete one of your queues.
• Enqueue: Add any data entries up to 4 KB in size to a specified queue.
• Read: Return data from a specified queue. No data-key is required, and data is returned in roughly the same order it was added to the queue.
• Dequeue: Remove a specified piece of data from a specified queue.

Specifically Designed for Use by Distributed Applications

A single queue can be used simultaneously by many distributed application components. There is no need for components to coordinate with each other to enable them to share a queue. A configurable read-lock feature is included to lower the incidence of duplicate messages when two applications are concurrently reading from the same queue.

Implemented to the Highest Standards for Performance and Reliability

The Amazon Simple Queue Service is built with the same stringent standards for performance and reliability as the rest of Amazon.com’s technology platform.

• Amazon Simple Queue Service is designed for transitory storage of relatively small messages. A single entry placed in a queue cannot be larger than 4 KB in size, and cannot be left in the queue for more than 30 days (data left longer than this will be deleted).
• During the Beta period, users of Amazon Simple Queue Service are limited to storing up to 4,000 queue entries at a time in all queues created by the same Subscription ID.
• During the Beta period, there are limited security restrictions on access to individual queues. Access is granted to another user or application if they can provide your AWS Subscription ID and the corresponding identifier of your queue.
• Applications should be prepared for the event where the same message is read more than once from the queue. In particular: A message may be returned by Read even though it has already been dequeued; and concurrent Read calls may return the same message to multiple readers. This behavior is a result of prioritizing reliable data storage (even in the face of hardware failures), and we expect such events to occur very infrequently. One way applications can cope with these occasional duplicates is by making the messages stored in the queue idempotent – that is, by ensuring that the effect of repeated receipt of a message is the same as that of receiving it once.
• Please see the Amazon Web Services Licensing Agreement for more details.