NATS & Docker Meetup in Toronto - August 2016 Implementing Microservices with NATS, Diogo Monteiro -How Aytra uses NATS -Benefits of using NATS for inter service communication -Lessons learned adopting NATS -Overview of Houston NATS library -Demo of Aytra You can learn more about NATS at http://www.nats.io

1. Implementing Microservices
with NATS

2. Agenda
● Microservices
● NATS
● Aytra
● Aytra + NATS
● Houston

3. Microservices
Microservices

4. Microservices - What?
● Micro benefits
○ Flexibility
○ Availability
○ Security
● Monolithic benefit
○ speed?
● Micro challenge
○ message passing

5. Microservices - Why?
● Scale application components independently
● Roll out features or experiments more freely
● Faster iteration
● Be aware of challenges
○ API interfaces
○ Communication
○ Latency
○ Tooling

6. NATS
NATS

7. NATS - What?
● The glue for your microservices
● Cloud-native messaging platform
● Highly performant
● Extremely lightweight
● Very flexible

8. NATS - Why?
● Compared to HTTP
○ Built in service discovery
○ Built in load balancer
○ Simpler & Faster
● Compared to other message queues
○ Simpler to implement and operate
○ Faster
● More complex use cases
○ Message/event persistence
○ At-least-once-delivery
○ Message Replay

10. Aytra - Application Management Platform

11. Aytra - Background
● Pivoted from a Cloud Management Platform
● Monolithic Java app
● Now has 20+ microservices written in Golang, Node-js and Java
● Team with < 5 developers
● Container based application
● CI/CD pipeline for microservices

12. +

13. Aytra + NATS - Overview

14. ● Different use cases
○ Two services need to exchange data and NATS is replacing HTTP
○ Event driven components
○ Notification
● NATS proxies
○ HTTP
○ WebSocket
○ Third party services
● Strategies
○ Request/Reply with timeout pattern for microservices that need to exchange data
■ Avoid the callback hell
○ NATS streaming for services that only publish data
Aytra + NATS

15. Aytra + NATS
● Guidelines for subject names
○ Service name
○ Version
○ Resource info
○ Param data
● GET /api/service/v1/resource/{id} -> service.v1.get.resource.*
● Internal subjects
○ service.v1.priv.resource.internal.action
● Queue groups
● Data format
○ JSON
○ ProtoBuf?

16. Aytra + NATS - Tooling
● Official NATS clients
● NATS exporter for monitor
● HTTP to NATS proxy
● Distributed tracing?
● Houston

17. Houston
Houston

18. Houston - Overview
● What?
○ Helper built around the NATS official clients
○ Provide boilerplates to wire microservices together
● Why
○ Abstract the communication framework from the microservices
■ Easier to update
■ Easier to create new microservices
○ Ensure all microservices implement the same messaging pattern
■ Current support for Golang, Java and Nodejs

19. Houston - Example
func AuthMiddleware(p *Passenger, elem reflect.Value) (*houston.ErrorBody){
return nil
}
func LoggerMiddleware(p *Passenger, elem reflect.Value) (*houston.ErrorBody){
return nil
}
rocket := houston.Rocket{
Route: "service.v1.put.person.*",
Params: houston.Params{{Index: 4, Name: "Id"},},
Group: "service",
Middleware: houston.Middlewares{LoggerMiddleware, AuthMiddleware},
Callback: func(p *person) (*houston.ErrorBody) {
fmt.Printf("Trying to update person with id %dn", p.Id)
return nil
}
}
controlTower.Build(rocket)
● Middleware chaining
● Parameter mapping
● Error handling
● HTTP like data model

20. Resources
● Houston
○ Golang: https://bitbucket.org/aytra/houston-go
● NATS Streaming
○ http://nats.io/documentation/streaming/nats-streaming-intro/
● NATS-HTTP Proxy
○ https://github.com/sohlich/nats-proxy
● NATS exporter
○ https://github.com/markuslindenberg/nats_exporter

21. Thank you

22. Questions?
diogogmt.com
@diogogmt