Accessing Multiple gRPC Services over a Single Connection

In scenarios where multiple gRPC services reside on the same server listening on a shared address, as in the example provided, it may seem redundant to establish separate connections to each service. This article aims to address why distinct connections are typically required and explores how to utilize a single connection to access multiple gRPC services.

Eliminating the Need for Multiple Connections

To effectively access various gRPC services hosted on the same server, you can leverage a single gRPC client connection. This approach involves initializing a grpc.ClientConn object and passing it to individual service client factories, enabling them to share the same underlying connection(s).

func main() {
    cc, err := grpc.Dial("localhost:6000", grpc.WithInsecure())
    if err != nil {
        log.Fatal(err)
    }
    c1 := pb.NewSubscriberServiceClient(cc)
    c2 := pb.NewDropperServiceClient(cc)
}

Reusing Generated Code from Protobuf

The generated gRPC code provided in the pb.go file encompasses all the necessary functionality for performing RPCs. Hence, there's no need for additional client-side implementations, unless specific logic needs to be executed automatically during each call.

Using an Interface for Convenience (Optional)

For cases where services have distinct method names, you can merge them into a single struct for added convenience.

type SubscriberDropper struct {
    pb.SubscriberServiceClient
    pb.DropperServiceClient
}

func main() {
    // ... as above ...
    sd := &SubscriberDropper{c1, c2}
}

By utilizing this approach, you can eliminate redundant connection establishments, resulting in a more efficient and optimized client-side implementation for your gRPC applications.