Missing Auto instrumented metrics from Netty using grpc-java

[bcarter97]

Description

Hello, I am using grpc-java with the grpc-netty implementation, and I was expecting to see HTTP Server metrics auto-instrumented from Netty as it is marked as supported for client/server metrics. I can see that rpc metrics are being instrumented, but no http metrics. Additionally I have disabled span suppression and also can't see any Netty traces.

• grpc-netty - 1.61.0 (transistively uses Netty 4.1.100.Final)
• opentelemetry-javaagent - 2.3.0

I see some logs such as:

Loading instrumentation netty [class io.opentelemetry.javaagent.instrumentation.netty.v4_1.NettyInstrumentationModule]
...
Transformed io.grpc.netty.NettyChannelBuilder -- jdk.internal.loader.ClassLoaders...
...
Applying instrumentation: netty [class io.opentelemetry.javaagent.instrumentation.netty.v4_1.NettyInstrumentationModule] on jdk.internal.loader.ClassLoaders...
...

The only metrics I can see are similar to rpc_server_duration_ and rpc_client_duration_

[laurit]

probably because our netty instrumentation does not support http/2

[bcarter97]

interesting, is it planned to be supported?

I can see the following issues, but nothing directly relating to implementing http2.

• HTTP Instrumentation on Quarkus/Netty doesn't work for TLS + HTTP/2 #8927
• Add tests that use HTTP/2 #3227

[laurit]

is it planned to be supported?

I definitely hope to see tests running with http/2, but I can not say anything about when this might happen.