Request-Response

Request-Response is an MEP.

With Request-Response a message is sent from one component to another with the expectation to receive a response, because the response is required for further processing.

Applications implementing the Request-Response pattern should have proper Exception Handling in place to handle timeouts, where it takes too long to receive a response.

For ESB implementations Request-Response could either be implemented with Queues or with Topics. If Queues are used, messages should always have a TTL that is approximately equal to the timeout value, because otherwise the Queue could gradually fill up over time.