Microservices @BlaBlaCar

A presentation about microservices at BlaBlaCar.

Talk given at sfPot March 2015 at SensioLabs

Transcript

1. Microservices
   @BlaBlaCar
   

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2. Olivier Dolbeau
   @odolbeau
   Web Architect
   About me
   

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4. What’s the v3?
   ● after the v2 (thanks cap’tain obvious!)
   ● Full sf2 application
   ● contains EVERYTHING
   ○ web
   ○ admin
   ○ workers
   ○ dead code
   ○ ...
   

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5. 18 août 2011
   First commit
   6 days after:
   Steve Jobs resigns as the CEO of Apple Inc.
   

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7. Thanks v3
   ● Pragmatic!
   ● Everything in the same place
   ● only one application to deploy
   ● only one application to explain to newcomers
   (even if a lot of time is needed to understand
   everything)
   It was a good choice at this moment.
   

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8. Figures
   

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9. 340 494
   NLOC
   There is “only” 268 041 NLOC for symfony/symfony
   

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10. 24 906
    Commits
    There is “only” 15 506 commits for symfony/symfony
    There is “only” 10 228 commits for joyent/node
    There is “only” 9 266 commits for twbs/bootstrap
    There is 44 809 commits for rails/rails (but it’s ruby… #troll)
    

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11. 53
    Contributors
    

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13. 3 537
    Tests
    There is “only” 17 593 tests for symfony/symfony… #ohwait
    

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14. 30
    minutes to run them all
    28 minutes for symfony/symfony… #fake
    

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15. 20
    minutes to deploy
    

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17. Problems of a very huge code base
    ● Very (VERY) Hard to maintain
    ● Deployment process (including tests) is too
    long
    

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18. “With minor change
    comes major bugs”
    Myself, based on my personal experience.
    

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19. Let’s do it again!
    V4? No!
    

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21. Microservices
    The new developer silver bullet!
    #troll
    

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22. Definition
    “In computing, microservices is a software architecture
    design pattern, in which complex applications are
    composed of small, independent processes communicating
    with each other using language-agnostic APIs. These
    services are small, highly decoupled and focus on
    doing a small task.”
    You know from where comes this definition
    

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23. How?
    Workers first.
    ● mail
    ● sms
    ● user-action
    ● …
    We now have 60+ workers in… 60+ git
    repositories.
    

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24. Pros
    ● easy to:
    ○ understand
    ○ write / launch tests
    ○ deploy
    ● always the same code base:
    ○ same command to consume
    ○ same deployment script
    ○ …
    ● We made OSS: swarrot/swarrot
    

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25. Cons
    ● process:
    ○ new repo
    ○ new build plan in bamboo
    ○ a bit of chef for deployment
    ● new side projects:
    ○ to configure our broker (Rabbit)
    ○ to deal with configuration
    ● increase ops complexity
    

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28. Think global!
    ● Multi DC. \o/
    ● Need to split data across the world.
    ● Need to shard data.
    

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29. But how to
    achieve this when
    you don’t even
    know how your
    application
    works?
    

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30. How to shard users?
    You gonna hate Doctrine ORM.
    You gonna hate all your listeners.
    You gonna hate everyone.
    

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31. Enter the
    gateway!
    

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32. Goals
    ● identify & isolate the business logic
    ● identify & isolate data calls
    ● without rewriting the whole application
    ● without impacting the actual delivery
    ● must be usable everywhere (not only in our
    main application)
    Do what we want with our data and our
    business
    

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33. Implementation
    Strict separation of concerns
    ● business
    ● data
    One repository for everything
    ● tried with more => complex for development
    ● still easily splittable
    

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35. Data
    ● 1 interface. Can have several
    implementations.
    ● easy to
    ○ add cache
    ○ change backend
    ○ shard data
    ● Strict rules:
    ○ findOne* => return an array or throw exception
    ○ findBy* => return an Adapter
    ○ ...
    

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36. ● Lots of entry points! (called “action”)
    ● Request / Response / Handler pattern
    ● Flat request / response => no objects. \o/
    ● can call 0-n times the data layer.
    Business
    

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39. ● concise
    ● event dispatched into RabbitMQ
    ● We always have a response object or an exception. No
    more null everywhere. \o/
    

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40. Pros
    ● Separation of concern
    ● The ability to isolate anything!
    ● strict rules (exceptions & co)
    ● easy to understand
    

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41. Cons
    ● versioning
    ● applications updates
    ● new side projects (again)
    ○ to deal with fixtures
    ● kind of duplicate code
    

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42. Cassandra for messaging
    User sharding
    Rating data isolation
    

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45. Facts
    ● Need to deploy the whole application
    ● 1 bundle
    ● 54 controllers
    ● 36 957 NLOC
    ● Lot of shared code
    ● Can break the website
    

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46. Goal
    ● Several independent applications
    ● Centralized application to handler
    permissions / connection
    ● A bit like SensioConnect for all Sensio
    products
    

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47. I hope...
    

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49. The silver bullet doesn’t exist!
    Microservices comes with several drawbacks
    but it is worth it!
    We will continue to move forward
    We need your help! ;)
    

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