I'm diving into using WebSockets for the first time and I'm trying to figure out the best way to confirm that messages sent between the client and server are actually received. I've been thinking about incorporating a unique identifier (UUID) for each message, which would help me track them until I get a confirmation back that they've been received. My idea is to create a Messenger class that holds a map where each UUID serves as the key, and it stores the associated socket, message payload, and a timer. Each outgoing message will be tagged with a UUID and logged in this map. When I get a confirmation from the client, I can then remove that message from the map. If I don't get a confirmation after some time, I might resend the message a few times before considering the user disconnected. What do you think about this plan? Is there a more effective way to handle message delivery and confirmations?
2 Answers
Your approach of using UUIDs to track message delivery sounds solid. However, you should consider how you’ll confirm that the acknowledgment was actually received. WebSockets are based on TCP, which does provide some degree of reliability, but it's not foolproof for your use case. If you aim for 'exactly once' delivery, exploring established protocols like AMQP or Kafka might be worthwhile. They handle message acknowledgment and delivery semantics very effectively, and using a proven system could save you a lot of hassle.
It sounds like you're implementing a system similar to what AMQP or Kafka does with message delivery. The messaging flow where the client subscribes, the server sends the message with a sequence number, and the client acknowledges receipt is key to ensuring delivery. If you're looking for better systems, I'd suggest looking into those as they have built-in mechanisms for these issues. Redis Streams is another option you might want to explore for its delivery guarantees.
Thanks for the advice! I’ll dive into how they implement message handling.
Great point! I hadn’t thought about those protocols. I’ll definitely check them out to see how they handle this kind of scenario.