This document discusses gRPC, an open-source high performance RPC framework created by Google. It provides benefits over REST such as binary encoding which allows for higher performance, as well as a contract-first approach using protocol buffers to define services. Protocol buffers can generate code for multiple platforms and allow flexible evolution of structures. gRPC uses HTTP/2 for a single connection with header compression. While REST is still necessary for some use cases, gRPC provides higher performance for internal APIs and microservices.

1. gRPC: Beyond REST
history repeats itself infinitely

2. About me
• JVM developer since 1998
• Cofounder @ CirculoSiete
• Staff @ JVM Mexico City
• @domix

3. History
• Lupine. Powered Courier by XEROX (1981)
• Bruce Jay Nelson coined the term ‘RPC’
• SUN’s RPC (ONC RPC) ~NFS
• CORBA (1991)
• RMI
• Burlap/Hessian

4. gRPC?
• Stands for ‘gRPC Remote Procedure Call’
• Open source project from Google hosted by the Cloud Native Computing
Foundation
• High Performance, general purpose standard base, RPC framework.
• Open sourced of ‘Stubby RPC’ at Google

5. Why gRPC?
• We already have REST|GraphQL, why?
• Maybe performance?
• https://goo.gl/yM7XPM
• https://goo.gl/oYY8dr
• https://goo.gl/TtzXad
• Contract first approach
• Multi platform

6. Performance
• HTTP/2
• Single TCP connection
• Binary framing layer
• Header compression
• Persistent connections
• http://www.http2demo.io

7. Contract first approach

8. Protocol Buffers
• Protocol buffers are a flexible, efficient, automated
mechanism for serializing structured data, smaller, faster,
and simpler than XML or JSON.
• You can update your data structure without breaking
deployed programs.
• Language/platform agnostic.
• You have to write a definition in a text file ‘.proto’.
• A compiler is needed to generate the desired source code.

9. syntax = "proto3";
package com.circulosiete.cursos.k8s;
import "google/protobuf/timestamp.proto";
import "google/protobuf/wrappers.proto";
import "google/api/annotations.proto";
option java_multiple_files = true;
option go_package = "warehouse";
message PageProductResponse {
google.protobuf.BoolValue first = 1; //unique numbered tag: 1
google.protobuf.BoolValue last = 2; //unique numbered tag: 2
google.protobuf.Int32Value number = 3; //unique numbered tag: 3
google.protobuf.Int32Value numberOfElements = 4; //unique numbered tag: 4
google.protobuf.Int32Value size = 5; //unique numbered tag: 5
google.protobuf.Int64Value totalElements = 6; //unique numbered tag: 6
google.protobuf.Int32Value totalPages = 7; //unique numbered tag: 7
repeated ProductModel content = 8;
}
message ProductModel {
int64 id = 1;
string name = 2;
string description = 3;
string price = 4;
google.protobuf.Timestamp createdAt = 5;
google.protobuf.Timestamp modifiedDate = 6;
int64 version = 7;
}

10. Contract!
service ProductService {
rpc Create (ProductRequest) returns (ProductResponse);
rpc Read (EntityId) returns (ProductResponse);
rpc Update (ProductModel) returns (ProductResponse);
rpc Delete (EntityId) returns (ProductResponse);
rpc Paged (Page) returns (PageProductResponse);
rpc List (Page) returns (stream ProductResponse);
}
service ValidacionService {
rpc ValidacionCreate (CreateRequest) returns (ValidacionResponse);
rpc ValidacionDelete (EntityId) returns (ValidacionResponse);
}

11. Multiplatform

12. gRPC compiler
• Takes proto files then generates specific source files
• It supports several plugins, for different programming languages
• It generates Server files, client files.

13. JVM
• Netty Powered!
• Gradle and Maven support
• Spring Boot community support

14. Live Coding!
gRPC intro demo

15. What about REST?

16. REST and gRPC
• REST is still necessary
• JavaScript applications
• Web Browser
• We can reuse our gRPC endpoints in REST
• https://github.com/grpc-ecosystem/grpc-gateway

17. gRPC gateway
• For now only supports Go Lang
• We have to use some Google Annotations
• The good
• Fast as hell!
• The Ugly
• Sometimes the Go Lang dev env is difficult to setup

18. Live Coding!
gRPC complete demo

19. Contact
• @domix
• domingo.suarez@gmail.com
• http://slideshare.net/domingo.suarez

20. Photos
• https://unsplash.com/photos/_cb5MjNG3DI
• https://unsplash.com/photos/1qkyck-UL3g
• https://unsplash.com/photos/w7ZyuGYNpRQ
• https://unsplash.com/photos/YucYLQ6Dm8A