ClintBoyett, To begin with, just to clarify - Notification hub is a single push resource holds cross-platforms (Android, iOS, and Windows versions) push information of one app. - 'All incoming Requests' – Is the total incoming requests for a notification hub (all platforms).
1. What does "All incoming Requests" mean?
A. This is the number of API calls for the given hub (send, installation, etc).
2. And how does it differ from "Incoming Messages"?
A. This is the number of send API calls for the hub ( is all send API calls)
3. How should I compare the above with "All Outgoing Notifications"?
A. Outgoing notifications is the number of pushes we sent to the PNS.
This will not match “Incoming Messages” as this is the number of target devices, not the number of send API calls.
So, in general it will not match Incoming Messages unless each send request only targets a single device
4.If you see a difference between "All Outgoing Notifications" and "Successful notifications" (in both directions), is there any way to find out the notifications that are failing or may be ongoing?
A. For namespaces which are Standard SKU, we provide telemetry/feedback via the following APIs:
https://learn.microsoft.com/rest/api/notificationhubs/get-notification-message-telemetry
https://learn.microsoft.com/rest/api/notificationhubs/get-pns-feedback