Allow broker session acquire timeout to propagate to acceptSession sync api

[anuchandy]

The synchronous acceptNextSession method retries the session requests if the broker signals no session is available (broker-timeout). This retry loop continues until a session is available or a client-side timeout occurs. When client-side timeout happens, an IllegalStateException with a "timeout on blocking read for" message is thrown. It's impossible to cancel a sent session request. If the client-side timeout triggers after sending a session request, but the broker finds a session before broker-timeout, the session may be temporarily locked until the lock expires.

To address this, synchronous acceptNextSession (and acceptSession(sessionId)) has been updated to propagate the broker-timeout error. To avoid breaking change, library will continue to throw IllegalStateException but with cause as TimeoutException. The client-side timeout is still applied which is useful in case of any unexpected network delay.

The .block(timeout) method is replaced with a new chain: .timeout(timeout, Mono.error(..)).onErrorMap(..).block(). The new chain will continue to throw the same error IllegalStateException but with TimeoutException as the cause. In cases of broker-side timeout, the cause will be TimeoutException("com.microsoft:timeout"), while for client-side timeout, the cause will be TimeoutException("Timeout on blocking read for .. (client-timeout)").

Also reduced the few log levels in ServiceBusSessionAcquirer to verbose from info.

[azure-sdk]

API change check

API changes are not detected in this pull request.

[conniey]

Thanks!

[anuchandy]

/azp run java - servicebus - tests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[anuchandy]

/azp run java - servicebus - tests

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[mwasaccess]

Hi @anuchandy,
we have a large number of TimeoutException entries in Application Insights logs when using azure-messaging-servicebus:7.17.7

My understanding is that TimeoutException is published to bounded-elastic thread by the publishError method of ServiceBusSessionAcquirer, but doOnError does not consume the exception - because of that it is automatically instrumented and logged by Application Insights agent. Shouldn't it use onError?