Detailed Subscription/@live and Defer/Stream usage data

[n1ru4l]

We do not collect any usage data for subscriptions and defer/stream.

Instead of HTTP request duration, we can monitor average Subscription length.

Useful metrics to track:

• Number of subscriptions on a Subscription Root field
• Number of payloads sent/values published for a subscription root field
• Subscription connection duration/length
• Error rate while setting up a subscription on a subscription root field
• Error rate for published subscription payloads per subscription root field
• Protocol used for a subscription operation (WS, WS Legacy, SSE)

[maxbol]

This would be a great feature for us 👍

Would like to add that support for live queries via the @live directive would be huge for us, and I suppose that could share implementation with usage for defer/stream fairly easily (i.e. a general solution for query executions that return AsyncIterable)?

[n1ru4l]

With #4176, we now support basic subscription usage reporting for conditional breaking changes.