Unexpected Messages

The AMPS C++ client handles most incoming messages and takes appropriate action. Some messages are unexpected or occur only in very rare circumstances. The AMPS C++ client provides a way for clients to process these messages. Rather than providing handlers for all of these unusual events, AMPS provides a single handler function for messages that can't be handled during normal processing.

Your application registers this handler by setting the UnhandledMessageHandler for the client. This handler is called when the client receives a message that can't be processed by any other handler. This is a rare event, and typically indicates an unexpected condition.

For example, if a client publishes a message that AMPS cannot parse, AMPS returns a failure acknowledgment. This is an unexpected event, so AMPS does not include an explicit handler for this event, and failure acknowledgments are received in the method registered as the UnhandledMessageHandler.

Your application is responsible for taking any corrective action needed. For example, if a message publication fails, your application can decide to republish the message, publish a compensating message, log the error, stop publication altogether, or any other action that is appropriate.