Hypermedia-Driven Orchestration in Microservices

Presented at; O'Reilly Software Architecture Conference, Boston, 2015.

The notion of Affordances has played seminal role in transforming our understanding of usable service design. It is key in Hypermedia architectural style and enables us to build resilient systems “at the scale of decades”.

With Microservice architectural style we end-up building systems that have higher degrees of freedom than those having monolith architectures. In such systems, effective orchestration and choreography are crucial. In this talk we explore hypermedia-enabled approach that leads to loosely-coupled, evolvable service design.

Transcript

1. Hypermedia-­‐Driven  
   Orchestra3on  in  Microservices  
   Irakli  Nadareishvili  -­‐  @inadarei  
   Director  of  Strategy,  API  Academy  
    
   March,  2015  
   

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2. 2   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
   Marc Andreessen
   

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3. 3   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
   Marc Andreessen
   

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4. 4   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
   Marc Andreessen
   “This is a pattern that we love
   to fund: unbundle X from Y,
   but then use the liberation of
   X as leverage to do amazing
   new things with X.”
   

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5. 5   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
   “Unbundling”
   

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6. 6   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
   «unbundled by»
   

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7. 7   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
   «unbundled by»
   

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8. 8   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
   «unbundled by»
   

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9. 9   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
   «unbundled by»
   

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10. 10   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Irakli  Nadareishvili  –  @inadarei  
    Hypermedia-­‐Driven  
    Orchestra3on  in  Microservices  
    

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11. 11   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    What are “Microservices ”?
    

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12. 12   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Martin Fowler:
    -­‐  hPp://marTnfowler.com/arTcles/microservices.html  
    “We  cannot  say  there  is  a  formal  
    definiTon  of  the  microservices  
    architectural  style,  but  we  can  aPempt  
    to  describe  what  we  see  as  common  
    characterisTcs  for  architectures  that  fit  
    the  label.  ”  
    

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13. 13   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    EVOLUTIONARY  DESIGN  
    Characteristics of a Microservice Architecture per Fowler:
    COMPONENTIZATION  VIA  SERVICES  
    ORGANIZED  AROUND  BUSINESS  CAPABILITIES  
    PRODUCTS,  NOT    PROJECTS  
    SMART  ENDPOINTS  AND  DUMB  PIPES  
    DECENTRALIZED  GOVERNANCE  &  DATA  MANAGEMENT  
    1  
    2  
    3  
    4  
    5  
    INFRASTRUCTURE  AUTOMATION/DESIGN  FOR  FAILURE  
    6  
    7  
    

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14. 14   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    We Know What It Is Not:
    Monolith
    

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15. 15   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    We Know It Is Popular:
    

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16. 16   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    

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17. 17   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    It is not just about technology
    

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18. 18   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Unbundling: greatest disruptor of tech industry
    “Microservices unbundle your business
    for internal and [controlled] external
    disruption”
    – Irakli Nadareishvili
    

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19. 19   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Microservice Architecture
    is complex
    Uncomfortable truth:
    

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20. 20   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Monolith is brittle, but has order
    

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21. 21   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Microservices: High Degree of Freedom
    

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22. 22   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Most of us are quite awful at
    designing distributed systems.
    Uncomfortable truth:
    

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23. 23   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    

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24. 24   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    

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25. 25   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    EVOLUTIONARY  DESIGN  
    Characteristics of a Microservice Architecture per Fowler:
    DECENTRALIZED  GOVERNANCE  &  DATA  MANAGEMENT  
    5  
    7  
    

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26. 26   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Watch-out for tight coupling!
    

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27. 27   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    We can build loosely-coupled,
    evolvable services, by designing
    them as Hypermedia APIs
    Solution we know works:
    

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28. 28   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Hypermedia per Fielding
    Architectural  Styles  and  the  Design  of  Network-­‐based  
    So\ware,  2001  
    -­‐  Roy  T.  Fielding  
    “Hypermedia  is  defined  by  the  
    presence  of  applicaTon  control  
    informaTon  embedded  within,  or    
    as  a  layer  above,  the  presentaTon    
    of  informaTon”  
    

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29. 29   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Or: response = data + controls
    API  server  would  have  to  send  client  
    not  just  sta$c  data,  but  also  controls  
    describing  API  affordances.  
    

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30. 30   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Challenge by Ioseb Dzmanashvili:
    Most  common  hypermedia  
    controls  facilitate  “a  single  step”.  
    

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31. 31   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    How do we orchestrate
    Loosely-coupled microservices
    for complex workflows?
    

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32. 32   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    E-­‐COMMERCE  
    BOOKING  TRAVEL  
    1  
    2  
    Examples:
    

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33. 33   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Booking Travel
    

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34. 34   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Diagram  by:  Clemens  Vasters    
    source:  hPp://vasters.com/clemensv/2012/09/01/Sagas.aspx    
    Saga: Long-Lived Compensating Transactions
    

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35. 35   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Link Relations for Saga:
    •  rel  =  “rouTng-­‐slip”  (new:  microformats)  
    •  rel  =  “compensaTngtx”  (new:  microformats)  
    @see:  hPp://rels.messages.io  
    

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36. 36   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    E-Commerce
    

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37. 37   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    BROWSING/DISCOVERY  –  “HYPERMEDIA  MAZE”  (AMUNDSEN)  
    CHECKOUT  –  SERVICE  ORCHESTRATION  
    POST-­‐PURCHASE  –  SERVICE  CHOREOGRAPHY  
    1  
    2  
    3  
    3 Types of Complex Workflows
    

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38. 38   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Maze Problems
    

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39. 39   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Maze+XML
    

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40. 40   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Checkout: Orchestration
    Checkout  
    1.  Collect  Shipping  Info   2.  Billing  Info   3.  Authorize  Payment  
    4.  Post-­‐purchase  processing  
    

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41. 41   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Orchestration for Wizard-Style WFs:
    •  rel  =  “next”  
    •  rel  =  “prev”  
    Standard  IANA  link  relaTons:  
    

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42. 42   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Post Purchase: Choreography
    Post-­‐Purchase  
    service  
    Shipping  Service  
    E-­‐mail  noTficaTon  service  
    SMS  NoTficaTon  Service  
    Purchase  
    Completed  
    event  
    Push  NoTficaTon  Service  
    «subscribes to»
    

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43. 43   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Service Choreography
    •  rel  =  “hub”  (IANA  standard)  
    •  rel  =  “sub”  (new:  microformats)  
    •  rel  =  “unsub”  (new:  microformats)  
    •  rel  =  “events”  (new:  microformats)  
    Async  and  event-­‐driven.    
    Standard:  Pubsubhubbub  
    @see:  hPp://rels.messages.io  
    

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44. 44   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    BROWSING/DISCOVERY  –  “HYPERMEDIA  MAZE”  (MIKE  AMUNDSEN)  
    CHECKOUT  –  SERVICE  ORCHESTRATION  
    POST-­‐PURCHASE  –  SERVICE  CHOREOGRAPHY  
    1  
    2  
    3  
    Types of Complex Workflows
    DISTRIBUTED  TRANSACTIONS  –  SAGA  (HECTOR  GARCIA-­‐MOLINA  &  KENNETH  SALEM  )  
    4  
    

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45. 45   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Are there more workflow types?
    Probably, but: next time!
    

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46. 46   ©  2015  CA.  ALL  RIGHTS  RESERVED.  
    Microservices ❤ Hypermedia-Driven Orchestration
    Photo  credit:  Corey  Seeman,  CC  BY-­‐NC-­‐SA  2.0.  hPps://www.flickr.com/photos/cseeman/14144834659  
    

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47. Director  of  Strategy,  API  Academy  
         
    Irakli  Nadareishvili    
    @inadarei  @apiacademy  @cainc  
    Slideshare.net/cainc  
    linkedin.com/company/ca-­‐technologies  
    ca.com  
    

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