一对多（唯一）的Azure Service Bus队列与主题

Question

I have an online service hosted on Azure, that asynchronously sends data to on-premise clients. Each client is identified by an unique code.

Actually there is a single topic, with a subscription for each client which has a filter on the unique code, that is sent as a parameter in the message. No message will ever be broadcasted to all the clients.

I feel that using topic this way is wrong. The alternative that comes to my mind is to use a dedicated queue for each client, that is created on first contact

Could this be a better approach?

Thanks

Answer 1

Creating a separate Queue for each client is not advisable. This is the problem solved by Topics.

If you have separate Queue for each client, then you need to send messages to multiple Queues from Server. This will become tedious when the number of clients increases.

Having a single Topic and multiple Subscriptions is easy to manage as the message will be sent only to a single Topic from Server.

Answer 2

In my opinion using Topics and Subscriptions is the right way to go. Here's the reason why:

Currently the routing logic (which message needs to go to which subscription) is handled by Azure Service Bus based on the rules you have configured. If you go with queues, the routing logic will need to come to your hosted service. You'll need to ensure that the queue exists before sending each message. I think it will increase the complexity at your service level somehow.

Furthermore, topics and subscriptions would enable you to do build an audit trail kind of functionality (not sure if you're looking for this kind of functionality). You can create a separate subscription that has a rule to deliver all messages ( True SQL Rule ) to that subscription along with client specific subscription.