A microservice is an independent runnable services that does one task effectively. The concept is rather than having one monolithic application, we break it up into independent services that can be easily maintained.
To effectively use microservices there has to be a way for the various independent services to communicate with each other.
There are two ways of communication between microservices:
1. REST, such as JSON or XML over http
2. gRPC – Lightweight RPC protocol brought out by Google
What is gRPC?
To understand gRPC we first take a look at RPC.
RPC(Remote Procedure Call) is a form of inter-process communication (IPC), in that different processes have different address spaces. RPC is a kind of request–response protocol. RPC enables data exchange and invocation of functionality residing in a different address space or process.
gRPC is based around the idea of defining a service, specifying the methods that can be called remotely with their parameters and return types. A client application can call methods on a server application as if it were a local object.
- gRPC uses the new HTTP 2.0 spec
- It allows for bidirectional streaming
- It uses binary rather than text and that helps keep the payload compact and efficient.
This is Google’s announcement for gRPC.
So whats the “g” in gRPC? Google? Per the official FAQ page, gRPC stands for gRPC Remote Procedure Calls i.e. it is a recursive acronym.
Protocol Buffers
gRPC uses protocol buffers as Interface Definition Language (IDL) for describing both the service interface and the structure of the payload messages.
Protocol buffers are a mechanism for serializing structured data. Define how you want your data to be structured once, then you can use special generated source code to easily write and read your structured data to and from a variety of data streams and using a variety of languages.
https://developers.google.com/protocol-buffers/docs/overview
Specify how you want the information you’re serializing to be structured by defining protocol buffer message types in .proto files. This message is encoded to the protocol buffer binary format.
message Person {
required string name = 1;
required int32 id = 2;
optional string email = 3;
}
gRPC in Go
go get -u google.golang.org/grpc go get -u github.com/golang/protobuf/protoc-gen-go
protobuf.Protobuf allows you to define an interface to your service using a developer friendly format.
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