Return/throw Error when Topic does not exist (Azure Service Bus with new topology) #1255
Description
Is your feature related to a problem?
When using Azure Service Bus and the new topology, we do not get an error when the topic for an event does not exist. In fact the exception is caught and swallowed in MessageDispatcher.
While we understand that this is by design, this has some downside for us:
- if we want to deploy topics and subscriptions separately, e.g. via Terraform, we get only limited feedback about mistakes, for instance when we forgot to add a topic
- if a topic disappears for any other reason (which may include accidential manual modification), we might not get instant feedback
- attempting to publish to an ASB topic that does not exist is pretty expensive/slow and includes retries, which affects other topics and queues too under higher load, see #00100320 in your internal support ticketing system
Describe the requested feature
We'd like a way to get instant feedback at runtime when we try to publish to a topic that does not exists in Azure Service Bus (whether or not anyone subscribes to it), either by:
- bubbling up the Exception (or throwing a new one)
- any interception mechanism so that we can throw an Exception ourselves or write error logs
Describe alternatives you've considered
- our Terraform plans check (obviously) that topics exist when we subscribe to them
- this does not solve the issue about events that are published but not subscribed (yet)
- we thought about a "never publish an event no one subscribes to", but we need this at least temporarily, so we can introduce an event and then let another team build their handlers