Dissecting SQS FIFO Queues — Does Ordered and Exactly Once Messaging Really Exist?

At first glance, Amazon’s First-In-First-Out (FIFO) message queues provide an excellent feature set for business-critical scenarios. With FIFO, the order in which messages are sent and received is strictly preserved. With exactly-once processing, message duplicates are not introduced into the queue, and consumers control when a message is made available for redelivery. Reading past the marketing hype, how well do FIFO queues work in the real world? This article takes a deep dive into SQS FIFO queues to test the claims of message ordering and exactly-once processing, paying particular care to the conditions under which these claims hold. [Read More]