Go OpenTelemtry gRPC Metrics Instrumention

It is an OpenTelemetry (OTel) metric instrumentation for Golang gRPC servers and clients based on gRPC Stats.

Install

$ go get github.com/mahboubii/grpcmetrics

Usage

Metrics are reported based on General RFC conventions specefications with some exceptions for following metrics where a normal counter is used instead of histograms to reduce the metrics cardinality:

1. rpc.server.requests_per_rpc
2. rpc.server.responses_per_rpc
3. rpc.client.requests_per_rpc
4. rpc.client.responses_per_rpc

Keep in mind durations, request.size and response.size are not reported by default. If you need to enable them check out the options.

Server side metrics

handler, err := grpcmetrics.NewServerHandler()
if err != nil {
    log.Panic(err)
}

server := grpc.NewServer(
    grpc.StatsHandler(handler),

    // disable default otelgrpc duration metric to avoid sending metrics twice:
    grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(
        otelgrpc.UnaryServerInterceptor(otelgrpc.WithMeterProvider(otelmetric.NewNoopMeterProvider())),
    )),
    grpc.StreamInterceptor(grpc_middleware.ChainStreamServer(
        otelgrpc.StreamServerInterceptor(otelgrpc.WithMeterProvider(otelmetric.NewNoopMeterProvider())),
    )),
)

Client side metrics

handler, err := grpcmetrics.NewClientHandler()
if err != nil {
    log.Panic(err)
}

connection, err := grpc.Dial("server:8080", grpc.WithStatsHandler(handler))