Towards In-Order and Exactly-Once Delivery using Hierarchical Distributed Message Queues
In today's world, distributed message queues are used in many systems and play different roles (e.g. content delivery, notification system and message delivery tools). It is important for the queue services to be able to deliver messages at large scales with a variety of message sizes with high concurrency. An example of a commercial state of the art distributed message queue is Amazon Simple Queuing Service (SQS). SQS is a distributed message delivery fabric that is highly scalable. It can queue unlimited number of short messages (maximum size: 256 KB) and deliver them to multiple users in parallel.