Do you create idempotent consumers? “At Least Once” message guarantees that a message will be delivered to a consumer once or many times. This means that you need to develop your consumers to be able to effectively handle duplicate messages. Not doing so could result in some bad outcomes of your system. For example, processing an order twice, would not likely be a good outcome. Why do message brokers support “At Least Once” messaging, and how do you handle duplicates? Here’s how to make idempotent consumers and be resilient to duplicate messages.

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0:00 Intro
0:33 Delivery Guarantees
1:19 At Least Once
3:46 Keeping Track of Processed Messages
9:09 Demo Application
10:14 Naturally Idempotent
11:13 Sagas

#idempotent consumers #duplicate messages #c sharp