Amazon SQS Introduces FIFO Queues with Exactly-Once Processing and Lower Prices for Standard Queues

You can now use Amazon Simple Queue Service (SQS) for applications that require messages to be processed in a strict sequence and exactly once using First-in, First-out (FIFO) queues. FIFO queues are designed to ensure that the order in which messages are sent and received is strictly preserved and that each message is processed exactly once.
Quelle: aws.amazon.com