Azure Notification Hub: installation id unique between hubs?

Question

Is the Installation ID from the azure notification unique? Something similar to a GUID? Something unique even between different namespaces?

Answer 1

For installation IDs, it's up to the developer to choose whatever string they choose. So if you wanted to use a GUID, you absolutely can do that. You could also use a user email or anything that fits your application needs.

For a registration ID (where Notification Hubs chooses the value) it is indeed unique per hub.

Here are some docs on registration management, and installations as well: https://docs.microsoft.com/en-us/azure/notification-hubs/notification-hubs-push-notification-registration-management#installations

I hope that helps.