TraceId Changed in PublishSubscribe ErrorChannel

[syedyusufh]

TraceId is getting changed if the ErrorChannel is configured as a PublishSubscribe channel.

Sample reproducer of the above problem
https://github.com/syedyusufh/traceId-publishsubscribe-channel.git

[artembilan]

This is not the problem with a PublishSubscribeChannel, or even its Executor configuration.
The problem is with how those errors are handled in the AbstractPollingEndpoint.
The logic is to stop an observation in the end of polling task:

			donePollingTask(pollingTaskError);

However an exception from there is bubbled as is:

		catch (Exception ex) {
			pollingTaskError = ex;
			if (ex instanceof MessagingException messagingException) { // NOSONAR
				throw messagingException;
			}

And only after that it is turned into a new ErrorMessage to be sent to the errorChannel of the poller.
Here we start a fully new flow for that ErrorMessage and therefore new trace could be initiated.

If you confirm that it is normal expectations that error flow has to be a part of the original polling task, then we will think how to deal with that observation not to be closed until we send such an ErrorMessage.

Thanks

[syedyusufh]

Yes @artembilan , without this in place, it is getting difficult to correlate and trace the messageFlow end to end including the error.
Kindly consider.

[artembilan]

Good.
Let's summarize then!

The AbstractPollingEndpoint should ensure to not close an opened observation until error message is published.
Right no the donePollingTask() is done unconditionally in the finally block of the pollForMessage() which is before a thrown exception is handed to the ErrorHandler.