Make the scope current when needed for grpc server instrumentation by ttddyy · Pull Request #3806 · micrometer-metrics/micrometer (original) (raw)

When grpc client uses non-blocking requests, the server calls interceptor#interceptCall multiple times first, then proceed to the listener#on... methods. It is different from blocking requests that call those methods sequentially per request. The behavior causes multiple scopes to be opened on the same thread in interceptCall and wrongly consumes them in on... methods.

This change compares the current scope held by the ObservationRegistry against the withheld scope. When they are different, make the withheld scope current; then, the subsequent logic can pick the proper target observation.

Closes micrometer-metricsgh-3805