Endpoints & consumption
How messages are pulled from sources that cannot push, and how request and response are handled.
These patterns cover the consuming side: polling sources on a schedule, scaling consumers for throughput, retaining messages for offline subscribers, and correlating synchronous or asynchronous replies.
Polling consumer. Pull work from a source that cannot push, on a schedule, and publish what it finds.
Competing consumers. Run several consumers against one queue to raise throughput without duplication.
Durable subscriber. Retain messages for a consumer while it is offline, then deliver on its return.
Request-reply. Send a request and wait for its matching response, correlated together.
Async request with callback. Send now and receive the answer later as a separate correlated inbound message.