gRPC

A Google Invention.

• Uses HTTP/2 as transport.
• Client - Server Oriented.
• gRPC clients talk to gRPC servers.

Programs can do remote function calls on other servers.

flowchart LR
%%{init: {'flowchart': {'curve': 'monotoneX'}}}%%
    subgraph cpp["C++ Service"]
        stub3["gRPC\nStub"]
    end

    subgraph ruby["Ruby Client"]
        stub1["gRPC\nStub"]
    end

    subgraph android["Android-Java Client"]
        stub2["gRPC\nStub"]
    end

    stub2 -->|"Proto Request"| cpp
    cpp -->|"Proto Response(s)"| stub2

    stub1 -->|"Proto Request"| cpp
    cpp -->|"Proto Response(s)"| stub1

Protocol Buffers

This defines the data structure to send.

• Small local records

• Messages

• end in .proto

message Person {
  string name = 1;
  int32 id = 2;
  bool has_ponycopter = 3;
}

… Gets fed into the protocol buffer compiler protoc

Allows name(), set_name()

Now the Person class can serialize and retrieve protocol buffer messages.

References

Introduction to gRPC | gRPC