Hey folks,
I tried to register a DLQ for the ProcessingGroup of a Saga - but it seems that it has no effect. During the init phase of the EventProcessingComponent DeadLetteringHandlerInvokers are registered for non-saga ProcessingGroups, but I don’t see this happening for Sagas.
Is that currently not supported? @Steven_van_Beelen ?
Cheers!
Stefan
Correct, @szilske, we do not support the Dead-Letter Queue for Sagas.
I thought we adjusted the Reference Guide to specify this, but apparently, that’s not the case (yet)… My apologies for that.
The main predicament for combining the Saga with a DLQ is knowing what the following events to enqueue are.
As the user controls adjusting the associations within the Saga Event Handler, this can and thus will change from event to event.
As such, the DLQ cannot guarantee the same behavior as for Event Processors, which is that it may proceed with the following events within the stream.
Hence, the DLQ can only ever block a Saga process entirely.
Although doable, it’s far less friendly.
Furthermore, the behavior to enqueue events is part of the Processing Group implementation.
Sagas are their own Processing Group implementation within the Framework, as they act rather differently.
So, since the behavior wouldn’t be optimal and the additional effort it would cost, we’ve decided against providing DLQ support for Sagas.