otgrpc

Go gRPC Opentracing Instrumentation

An attempt to use Opentracing with gRPC services. The official grpc-opentracing library currently only supports tracing unary calls. This library makes use of gRPC stats.Handler interface to add tracing to gRPC streams as well.

The obvious approach to add tracing would be to make use of gRPC interceptors. However, the current interceptor interfaces lack the fuctionality to effectively add tracing information to the calls. Go gRPC has a built-in tracing mechanism that hooks into x/net/trace, but, the captured data is not accessible from external code. This leads us to the stats.Handler interface which is primarily designed for stats gathering but, in the process, gives us access to all interesting events that happen during a RPC -- which can be used to gather the tracing information we need.

Usage

Grab the library:

go get github.com/charithe/otgrpc

Client side:

tracer := // Tracer implementation

th := otgrpc.NewTraceHandler(tracer)
conn, err := grpc.Dial(address, grpc.WithStatsHandler(th))
...

Server side:

tracer := // Tracer implementation

th := otgrpc.NewTraceHandler(tracer)
server := grpc.NewServer(grpc.StatsHandler(th))
...

Options

Limit tracing to methods of your choosing

tf := func(method string) bool {
    return method == "/my.svc/my.method"
}

th := otgrpc.NewTraceHandler(tracer, orgrpc.WithTraceEnabledFunc(tf))

Attach payloads as Span log events

th := otgrpc.NewTraceHandler(tracer, otgrpc.WithPayloadLogging())