Azure Service Bus Topics, Subscription Rules Deleted

Question

We're using Service Bus Topics as the engine for a pub/sub system. Our logic involves our NodeJS services hooking up to a topic with multiple subscriptions. For each subscription we remove $Default (TrueFilter) and create a CorrelationFilter on Label property in the message header and don’t apply AutoDeleteOnIdle setting in the subscription as we want to make sure that our subscriber functions keep running until a service is up.

Issue

Last week it happened multiple times that our CorrelationFilter rule on some subscriptions got deleted automatically. We aren’t able to understand why our CorrelationFilter rule is being deleted.

This question can be boiled down like so: Can something cause rules to be removed after a certain time?

Answer 1

Can something cause rules to be removed after a certain time?

Subscription rules (SQL, Correlation, or Boolean) are never removed by the broker as it would have a devastating impact on the tenants of the service. I would advise reviewing your system and anything that has access to the namespace with management rights to see what's going on. Alternatively, rotate the keys (primary and secondary). If you have Managed Identity enabled, verify what has access.