[Service Bus] In flight messages get ignored in batch receiver if timer runs out

[ramya-rao-a]

This issue is a follow up from #6004 (review)

When receiveMessages() is called we resolve the returned promise in the below scenarios

• required number of messages are collected
• or the wait time that was provided has elapsed
• or more than 1 sec has passed since last message was received

In the second and third cases, it can be possible that rhea received a message, fired the message event which then got ignored because we removed the listeners in preparation to resolve the promise. Such in flight messages get ignored, which is not a big deal in peek lock mode, but results in data loss in case of receive and delete mode.

This issue is to first investigate if the above is possible and then to explore solutions.

cc @ramya0820

[richardpark-msft]

Moving to August - we should definitely get to this investigation before release.

[richardpark-msft]

At this point we've done a lot of work in this area and cases 2 and 3 above have been covered (and had fixes). I feel comfortable closing this.

Fixes:

• PR 13374
• PR 12772
• PR 12908
• PR 13073