This document discusses inter-process communication in microservices architectures using gRPC and Protocol Buffers. It begins with an overview of moving from a monolithic to a microservices architecture and the challenges of communication between independent services. It then covers considerations for building high performance APIs and why gRPC and Protocol Buffers are well-suited for microservices. The remainder details what gRPC is, how Protocol Buffers work, and how gRPC uses Protocol Buffers to provide a framework for remote procedure calls between services.

1. Inter-Process
Communication in
Microservices using gRPC
Shiju Varghese
https://medium.com/@shijuvar
Microservices & Serverless
April 29, 2017, Bangalore

2. About Me
• Consulting Solutions Architect and Trainer
• Focused on Golang, Microservices and Cloud-
Native distributed systems architectures
• Published Author: “Web Development with Go” and
“Go Recipes”
• Honoured with Microsoft MVP award seven times
• Blog: https://medium.com/@shijuvar

3. Agenda
• Inter-Process communications in Microservices
architecture
• Building high performance APIs with gRPC and
Protocol Buffers

4. Microservices Architecture

5. Monolithic Architecture
Catalog Management
Customer Accounts
Orders Management
Payment
Monolithic
Database
Monolithic E-Commerce App
eCom Store Web
Shipment

6. Moving to Microservices
Catalog Management
Customer Accounts
Orders Management
Payment
eCom Store Web
Shipment
Catalog DB
Accounts DB
Orders DB
Payment DB
Store DB
Shipment DB

7. Microservices
• Software broken up into functional components
• Componentization via Services in which each service is
packaged as one unit of execution
• Independent, autonomous process with no dependency
on other Microservices
• Autonomous services around Bounded Context
• Decentralization of data management
• Independently replaceable and upgradeable

8. Challenges
• A business transaction may span into multiple
autonomous services
• Decentralization of data management
• Communications between Microservices without
having any performance bottleneck

9. Inter-Process Communications
between Microservices
• Communications over high performance APIs
• Event-Driven architecture using messaging
systems

10. Design Considerations for Building APIs
• High Performance
• Scaling APIs into millions (even billions) of APIs calls
• Wire format; Serialisation and deserialisation of
messages
• Building streaming APIs
• RESTful Vs RPC?
• Text encoding Vs binary encoding?

11. Why not REST
• Uses HTTP/1.x; Separate TCP Connection per request
• Text on the wire; Not performance efficient
• Harder API evolution
• Not Domain-Specific
• Not strongly-typed
• Lack of streaming capabilities

12. gRPC and Protocol Buffers

13. What is gRPC
• High performance, open-source universal RPC framework
• A Cloud Native Computing Foundation(CNCF) project
• Open source version of Google’s internal framework Stubby
• Uses Protocol Buffers as the IDL
• HTTP/2 for transport
• Bi-Directional streaming
• RPC is efficient, domain-specific and strongly-typed
• Works across languages and platforms

14. Protocol Buffers
• Google's language-neutral, platform-neutral,
extensible mechanism for serialising structured data
• IDL - Describe once and generate interfaces for
multiple languages
• Structure of the Request and Response
• Binary format for network transmission
• Supports multiple languages

15. Communication between
gRPC Server and Client app

16. Types of RPC Methods
• Simple RPC
• Server-side streaming RPC
• Client-side streaming RPC
• Bi-directional streaming RPC

17. gRPC Workflow
ProtoBuf
Definitions
protoc
Compiler
Go
Ruby
Java gRPC Server
gRPC Client
Define1 Compile2
Implement3Generate Code
protoc --go_out=plugins=grpc

18. Demo App

19. grpc-gateway - gRPC to
JSON Proxy Generator

20. medium.com/@shijuvar
linkedin.com/in/shijuvar
email: gophermonk@gmail.com
THANK YOU
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