Message Acknowledgements in EMS

This post is the continuation of the Previous posts, So please read those also.

There are 3 levels of acknowledgements:

1. DUPS_OK_ACKNOWLEDGE, for consumers that are tolerant of duplicate messages.
2. AUTO_ACKNOWLEDGE, in which the session automatically acknowledges a client’s receipt of a message.
3. CLIENT_ACKNOWLEDGE, in which the client acknowledges the message by calling the message’s acknowledging method.

The following describes the steps in message delivery and acknowledgement:

1. A message is sent from the message producer to the machine on which the TIBCO Enterprise Message Service server resides.
2. The EMS server acknowledges that the message was received.
3. The server sends the message to the consumer.
4. The consumer sends acknowledgement to the server that the message was received.
5. In many cases, the server then confirms acknowledgement to the consumer. Acknowledgement from the consumer to the server prevents the delivery of duplicate messages.