I am currently evaluating HiveMQ’s cluster support in the enterprise version. First tests show a very promising behavior for scenarios in which cluster nodes fail and a failover of QoS 1 sessions has to happen for reconnecting clients with (clean_session=false). To build up some trust in the behavior, I would like to better understand (on a concept level) how HiveMQ implements the session replication. Would it be possible to share some details here, so I can verify that the behavior fits our needs?
Here are some questions I have - all relate to QoS 1 sessions & replica-count>1:
- Is a successful replication of the session ensured before acknowledging a received message to a publisher? (In other words: Can a publisher be sure that a published message was replicated to at least one other broker node once it receives an acknowledgement?)
- What steps need to be taken to achieve an in-order delivery of QoS 1 messages while maintaining high-availability features?
Thanks in advance for your support.