1.
Leaving The Monolith
thanks to Event Sourcing
Migrations, Event Sourcing, AWS, and other things of the meter
@JavierCane#scpna - Software Craftsmanship Pamplona

2.
@JavierCane#scpna - Software Craftsmanship Pamplona
Saliendo del monolito,
al Rico Eventito
Migraciones, Event Sourcing, y otras cosas del meter

3.
Welcome!
I’m Javier Ferrer González
@JavierCane

4.
Greetings to Sergi!
@SergiGP
Welcome!

5.
Contents
! Starting point
! Needs
! Action plan
! Flow example
! Conclusions

6.
1.
Starting point
Context

7.
Starting point
Context
! Mobile first application
! Crazy growth (ads in TV in USA and Turkey)
◕ External services (Parse, Kahuna…)
◕ In-house API
! Where do we go
◕ Microservices architecture
◕ Event Sourcing
◕ Orchestration Layer

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2.
Needs
New chat system!

9.
Needs
New chat system!
! From:
◕ REST API
◕ “Chat” (messaging system)
! To:
◕ WebSockets (better UX)
◕ Chat
◕ Isolated from API service
◕ Backwards Compatible (mobile!)
◕ Scale!

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3.
Action plan
Maintaining Backwards Compatibility (BC)

11.
Action plan
Maintaining BC
! Develop new chat with Scala and Akka, and WS
! Maintain BC taking advantage of Event Sourcing

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Action plan
Maintaining BC

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Action plan
Maintaining BC

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Action plan
Maintaining BC
! Why not sync through DB?
◕ Share DB: K.A.O.S.
◕ Doesn’t scale
◕ Coupling

15.
Action plan
Maintaining BC

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Action plan
Maintaining BC
! Why not sync through SQS?
◕ Doesn’t scale

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Action plan
Maintaining BC

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Action plan
Maintaining BC
! Why?
◕ Scale
◕ Decoupled
◕ Open-Closed Principle compliant at a services level

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4.
Flow example
Maintaining BC

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From the new chat to
the legacy one

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Flow example
Maintaining BC

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From the legacy chat to
the new one

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Flow example
Maintaining BC

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5.
Conclusions

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Conclusions
! Event Sourcing ~~ DIP at a services level
◕ Dependency Inversion Principle (CodelyTV video)
◕ Allow OCP: One SNS publishes to many SQS
◕ Encourage SRP
◕ Decoupleeeeee

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Conclusions

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Conclusions
! Isolated services
◕ Different technologies
◕ Different context
◕ Change context => Mental challenge
! AWS vs RabbitMQ
◕ Go fast => AWS
! From PHP to Scala: 🙃 🙂 🙃 💃 🙃 😀 😐 😳 🤔 🙂 🙃 🙂 …
! Know more at #SCBCN16! (October 1st & 2nd in BCN)

28.
References / To take away
! A Series of Fortunate Events
! The anatomy of Domain Event
! 6 Code Smells with your CQRS Events and How to
Avoid Them
! json:api standard
! Sending Amazon SNS Messages to Amazon SQS
Queues
! Subscribing a Queue to an Amazon SNS Topic

29.
Questions?
Thanks!
Contact
@JavierCane || @SergiGP
javier.mailserio@gmail.com
Codely.TV

30.
Credits
! Presentation base template by SlidesCarnival
! Graphics generated using draw.io