gRPC-sample

This is a sample golang application to practice gRPC communication.

There are two components, a client and a server, which emulate a Memcached-style in-memory key-value store.

Although we only store integer values in this example, for the purpose of this exercise we can assume the value has a much larger memory footprint than the key, necessitating streaming values for bulk operations.

This way we can exercise different styles of gRPC communication:

1. Unary RPC (GET, SET)
2. Server-to-client Streaming RPC (GETBULK)
3. Client-to-server Streaming RPC (SETBULK)

The following style is not yet exercised in this example:

1. Bidirectional Streaming RPC

Usage

After starting the server (see Building section below), you can start the client which serves as a REPL for Memcached-like commands:

Connected. Commands are:

        SET <key> <value>
        GET <key>
        GETBULK <key1>,<key2>,...
        SETBULK <key1> <value1>,<key2> <value2>,...
        EXIT

> GET abc
Error getting value rpc error: code = Unknown desc = Missing key
> SET abc 7
> GET abc
Got value 7

Building

Protobuf

To compile kvstore.proto you will need the protoc-gen-go Protobuf compiler plugin for Go. For more details see the gRPC Quick Start guide.

$ protoc --go_out=paths=source_relative,plugins=grpc:. kvstore.proto

Server

$ go run server/server.go
2020/06/10 19:58:33 Starting server on port :50051

Client

$ go run client/client.go 
Connecting client on localhost:50051