Last week I introduced RabbitMQ streams and how you could produce and consume streams through the RabbitMQ.Stream.Client in .NET.
The default Producer is really low-level and leaves a lot of things to be implemented by us. For example, we have to increment the PublishingId ourselves with every Send() operation. Let’s find out how we can improve this through Reliable Producers.
Introducing Reliable Producers
Reliable Producer builts on top of the Producer and adds the following features:
- Provide publishingID automatically
- Auto-Reconnect in case of disconnection
- Trace sent and received messages
- Invalidate messages
- Handle the metadata Update
Provide publishingID automatically
When using a Reliable Producer it retrieves the last publishingID given the producer name. This means that it becomes important to choose a good reference value.
Auto-Reconnect
The Reliable Producer will try to restore the TCP connection when the Producer is disconnected for some reason.
Trace sent and received messages
The Reliable Producer keeps each sent message in memory and removes it from memory when the message is confirmed or goes in timeout.
Invalidate messages
If the client doesn't receive a confirmation within 2 seconds the Reliable Producer removes the message from the internal messages cache. The user will receive ConfirmationStatus.TimeoutError in the ConfirmationHandler.
Handle the metadata update
If the streams topology changes (ex:Stream deleted or add/remove follower), the client receives an MetadataUpdate event. The Reliable Producer detects this event and tries to reconnect the producer if the stream still exist or closes the producer/consumer when the stream is deleted.
Sending messages through Reliable Producers
The Reliable Producer also provides a Send() method but only requires the message as parameter because the publishingId is provided automatically: