Service Bus cost increase

[simonness]

Service Bus costs jumped 2000% on 11th March for a namespace we use in a production environment and 13th March for a namespace we use in a non-production environment. Both namespaces are solely used by Azure Function Service Bus triggers.

I'm confident this jump in cost is not down to a change made on our side. We made no relevant code changes, and always release to non-prod before prod. Furthermore the non-prod namespace is hardly used, certainly under 100 messages per month, indicating this cost is most likely from the Azure Function Service Bus trigger "at rest".

Has there been any change to Azure Functions on Microsoft's side that could have caused this change in cost? Is anyone else seeing this?

The cost analysis shows a consistent higher daily cost from the dates mentioned.