What is the max number (if any) of subscriptions a Windows Azure Service Bus Topic can have?

Question

I'm considering an architecture that could have tons of subscribers to a single topic. Like tens or hundereds of thousands of individual subscribers. Each would have a SQL filter, something like:

User = 'SomeUserIdentifier'

Just wondering if I'm going to run into a max number of subscriptions on a topic at some point.

Answer 1

Service Bus supports up to 2,000 subscriptions per topic. (source)

But if you need to go beyond the 2,000 subscriptions limit you can create multiple levels of subscriptions with the Auto-forwarding capabilities of a Subscription. This means you could have the following:

Topic A

• Subscription 1 -> Auto-forward -> Topic A1 -> Subscription A1.1, Subscription A1.2, ...
• Subscription 2 -> Auto-forward -> Topic A2 -> Subscription A2.1, Subscription A2.2, ...
• ...
• Subscription 2000 -> Auto-forward -> Topic A2000 -> Subscription A2000.1, Subscription A2000.2, ...

This means you would have virtually no limit on the number of subscriptions you could have on a topic.