Hello everybody,
I understand the logic behind ordered topics but I'm not sure I understand the rationale behind the requirement that clients have to send the acknowledgementsÂ(e.g. PUBACK packets) in order.
There are server implementations that guarantee in-order delivery that don't enforceÂthis requirement on the client (see VerneMQ and EMQX which both don't require the acks to be sent back in order).
I want to make sure that I'm not missing anything though so I decided to post here and ask for a comment. Can somebody please explain why clients should send the acks in order? Can't the server handle gaps so that, given messages 1,2,3,4, if 3 is acknowledged and the client disconnects, the server redelivers 1,2,4?
Thanks!