Queues are a very common piece of infrastructure. It offers First In, First Out (FIFO) message delivery to one or more competing consumers.
Join the DZone community and get the full member experience. Queues are a very common piece of infrastructure. It offers First In, First Out (FIFO) message delivery to one or more competing consumers. As the queue grows the last item added to the queue typically must wait longer to be processed. Just like someone waiting in line to order food, the first one in line gets to order first. Microsoft Azure Service Bus (ASB) is Microsoft’s premier enterprise-level messaging technology that uses this principle of FIFO. ASB queues always have two parties involved-a producer and a consumer. The producer pushes the messages into the queue, while the consumer periodically polls for messages and consumes them. The main queue holds the messages until it is consumed or moved to the dead-letter queue. The purpose of the dead-letter queue is to hold messages that cannot be delivered to any receiver, or messages that could not be processed. The DLQ is mostly like any other queue, except that messages can only be submitted via the dead-letter operation of the parent entity. In addition, time-to-live is not observed, and you can’t dead-letter a message from a DLQ. The dead-letter queue fully supports peek-lock delivery and transactional operations. There is no automatic clean-up of the DLQ. Messages remain in the DLQ until you explicitly retrieve them from the DLQ. Dead-letter queues are the safest bet when we are using Azure Service Bus. If for whatever reason message could not be processed by a receiver, we could move such a message to a dead letter queue.
