Integrating RabbitMQ with database transactions

Question

Imagine the situation:

var txn = new DatabaseTransaction();

var entry = txn.Database.Load(id);
entry.Token = \"123\";
txn.Database.Update(entry         


        

Answer 1

RabbitMQ encourages you to use publisher confirms rather than transactions. Transactions do not perform well.

In any case, transactions don't usually work very well with a service oriented architecture. It's better to adopt an 'eventually consistent' approach, where failure can be retried at a later date and duplicate idempotent messages are ignored.

In your example I would do the database update and commit it before publishing the message. When the publisher confirm returns, I would update a field in the database record to indicate that the message had been sent. You can then have a sweeper process come along later, check for unsent messages and send them on their way. If the message did get through, but for some reason the confirm, or subsequent database write failed, you will get a duplicate message. But that won't matter, because you've designed your messages to be idempotent.