grpc
grpc 官方文档
https://grpc.io/docs/what-is-grpc/introduction/
https://grpc.io/docs/what-is-grpc/core-concepts/
In gRPC, a client application can directly call a method on a server application on a different machine.
By default, gRPC uses Protocol Buffers, Google’s mature open source mechanism for serializing structured data (although it can be used with other data formats such as JSON).
gRPC lets you define four kinds of service method:
1,Unary RPCs
2,
