So you Want to Distribute your GraphQL Schema?

Transcript

1. @__xuorig__
   GraphQL Conf 2019
   So You Want To Distribute Your
   GraphQL Schema?
   

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2. GraphQL Conf 2019
   @__xuorig__
   Marc-André Giroux
   Montréal, Canada
   
   @__xuorig__
   

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4. GraphQL Conf 2019
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   Distributed GraphQL?
   

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5. GraphQL Conf 2019
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   Distributed GraphQL
   The Basic Case
   GraphQL API
   query GetRepositories {
   viewer {
   repositories(first: 10) {
   name
   owner {
   name
   }
   }
   }
   }
   

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6. GraphQL Conf 2019
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   Distributed GraphQL
   Distributed Case
   query GetRepositories {
   viewer {
   repositories(first: 10) {
   name
   owner {
   name
   }
   }
   }
   }
   Search Service
   Monolith
   User Service
   

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7. GraphQL Conf 2019
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   Distributed GraphQL
   Distributed Case
   query GetRepositories {
   viewer {
   repositories(first: 10) {
   name
   owner {
   name
   }
   }
   }
   }
   Search Service
   Monolith
   User Service
   ?
   

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8. GraphQL Conf 2019
   @__xuorig__
   Distributed GraphQL
   Distributed Case
   query GetRepositories {
   viewer {
   repositories(first: 10) {
   name
   owner {
   name
   }
   }
   }
   }
   Search Service
   Monolith
   User Service
   

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9. GraphQL Conf 2019
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   Schema Stitching
   

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10. GraphQL Conf 2019
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    Schema Federation
    

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11. GraphQL Conf 2019
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    GraphQL Gateway
    

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12. GraphQL Conf 2019
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    GraphQL Modules
    

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13. GraphQL Conf 2019
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    Namespaces
    

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14. GraphQL Conf 2019
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    Schema Delegation
    

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15. GraphQL Conf 2019
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    Schema Composition
    

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16. GraphQL Conf 2019
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17. "Though there is only one graph, the
    implementation of that graph should
    be federated"
    - https://principledgraphql.com/
    GraphQL Conf 2019
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18. GraphQL Conf 2019
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19. GraphQL Conf 2019
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20. GraphQL Conf 2019
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    The API Gateway pattern is far from
    new...
    

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21. GraphQL Conf 2019
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    So what's different this time?
    

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22. GraphQL Conf 2019
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    API Gateways
    Endpoint Based
    GET /users/1
    Search Service
    Monolith
    User Service
    

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23. GraphQL Conf 2019
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    API Gateways
    Endpoint Based
    GET /search?q=stuff
    Search Service
    Monolith
    User Service
    

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24. GraphQL Conf 2019
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    In some ways, not so different...
    

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25. GraphQL Conf 2019
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    Schema "Stitching"
    

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26. GraphQL Conf 2019
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    query {
    search(query: "stuff") {}
    issue(id: "abc") {}

    user(id: "def") {}
    }
    Search Service
    Monolith
    User Service
    

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27. GraphQL Conf 2019
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    Search Service Monolith
    User Service
    type Query {
    search(query: String!): [SearchResult!]
    }
    type Query {
    user(id: ID!): User
    }
    type Query {
    issue(id: ID!): Issue
    }
    

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28. GraphQL Conf 2019
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    finalSchema = merge(user_schema, search_schema, monolith_schema)
    

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29. GraphQL Conf 2019
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    Gateway
    type Query {
    search(query: String!): [SearchResult!]
    user(id: ID!): User
    issue(id: ID!): Issue
    }
    

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30. GraphQL Conf 2019
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    In other ways, much more complex.
    

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31. GraphQL Conf 2019
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    API Gateways
    •Types, and even singular fields, can possibly be resolved by `n`
    services
    
    •Nested fields may need to be resolved outside the current service
    
    •Resolution logic is extremely complex (Avoiding N+1's, handling
    failure scenarios within resolution of a query, etc)
    GraphQL
    

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32. GraphQL Conf 2019
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    Search Service Monolith
    User Service
    type Query {
    search(query: String!): [SearchResult!]
    }
    union SearchResult = User | Issue
    type Query {
    user(id: ID!): User
    }
    type Query {
    issue(id: ID!): Issue
    }
    type Issue {
    owner: User!
    }
    Schema Stitching
    The Harder Parts
    

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33. GraphQL Conf 2019
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    Schema Stitching
    The Harder Parts
    Search Service Monolith
    User Service
    type Query {
    search(query: String!): [SearchResult!]
    }
    union SearchResult = User | Issue
    type Query {
    user(id: ID!): User
    }
    type Query {
    issue(id: ID!): Issue
    }
    type Issue {
    owner: User!
    }
    

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34. GraphQL Conf 2019
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    •Individual Schemas are invalid on their own, only the final merged
    schema is valid.
    
    •The Gateway is now much more complex than just simple
    "proxying"
    Schema Stitching
    The Harder Parts
    

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35. GraphQL Conf 2019
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    finalSchema = merge(user_schema, search_schema, monolith_schema)
    

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36. GraphQL Conf 2019
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    finalSchema = merge(user_schema, search_schema, monolith_schema)
    

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37. GraphQL Conf 2019
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    finalSchema = merge(...schemas, links)
    

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38. GraphQL Conf 2019
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    Schema Stitching
    Developer Experience
    Search Service Monolith
    User Service
    Gateway
    Add the "User.pullRequests" field
    Add the "User.pullRequests" link
    

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39. GraphQL Conf 2019
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    •Brittle Gateway Code
    
    •Business logic often creeping into the Gateway
    
    •What we wanted to decentralize often ends up being centralized
    Schema Stitching
    Developer Experience
    

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40. GraphQL Conf 2019
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41. https://www.apollographql.com/docs/graphql-tools/schema-stitching/
    

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42. GraphQL Conf 2019
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    If not schema stitching, then what?
    

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45. GraphQL Conf 2019
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    Hard Mode: The Magic Gateway
    

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46. GraphQL Conf 2019
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    Schema Federation: Don't miss
    tomorrow's talk!
    

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48. GraphQL Conf 2019
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    Let's take a step back
    

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49. GraphQL Conf 2019
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    Is there a more pragmatic approach
    to a GraphQL Gateway?
    

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50. GraphQL Conf 2019
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    Why are we here today? Why
    GraphQL?
    

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51. GraphQL Conf 2019
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    One Size Fits All APIs
    

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52. GraphQL Conf 2019
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    Netflix's Server Side Adapters
    https://medium.com/netflix-techblog/embracing-the-differences-inside-the-netflix-api-redesign
    

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53. GraphQL Conf 2019
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    Netflix's Server Side Adapters
    - Daniel Jacobson
    The better approach for handling API
    design [...] is to create true separation
    of concerns, rather than have all
    server-side decisions made by the
    API provider.
    

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54. GraphQL Conf 2019
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    SoundCloud's BFF Pattern
    

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55. GraphQL Conf 2019
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    GraphQL can be our BFF
    

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56. GraphQL Conf 2019
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    GraphQL can be our server side
    client adapter engine
    

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57. GraphQL Conf 2019
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    https://medium.com/netflix-techblog/embracing-the-differences-inside-the-netflix-api-redesign-15fd8b3dc49d
    

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58. GraphQL Conf 2019
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    GraphQL queries are kind of on-
    demand resource representations
    

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59. GraphQL Conf 2019
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    GraphQL API
    query {
    viewer {
    repositories(first: 10) {
    name
    owner {
    name
    }
    }
    }
    }
    "I want this resource in this shape pls"
    

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60. GraphQL Conf 2019
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    GraphQL API
    query {
    viewer {
    repositories(first: 10) {
    name
    owner {
    name
    }
    }
    }
    }
    "K, it's accessible at /api/abc"
    

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61. GraphQL Conf 2019
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    GraphQL API
    GET /api/abc
    

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62. GraphQL Conf 2019
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    We're basically all using REST at this
    point
    

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63. GraphQL Conf 2019
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    This actually sounds like a great
    feature for an API gateway!
    

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64. GraphQL Conf 2019
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    What are we looking for in an API
    Gateway?
    

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65. GraphQL Conf 2019
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    Decouple the clients from the
    services involved in the consumed
    use cases
    

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66. GraphQL Conf 2019
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    Avoid domain logic #
    

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67. We remain concerned about business logic and process
    orchestration implemented in middleware [...] Vendors in the
    highly competitive API gateway market are continuing this
    trend by adding features through which they attempt to
    differentiate their products. This results in OVERAMBITIOUS
    API GATEWAY products whose functionality — on top of
    what is essentially a reverse proxy — encourages designs
    that continue to be difficult to test and deploy.
    https://www.thoughtworks.com/radar/platforms/overambitious-api-gateways
    GraphQL Conf 2019
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68. GraphQL Conf 2019
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    Do we really want to commit to
    GraphQL for inter-service
    communication?
    

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69. GraphQL Conf 2019
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    Not all of us are starting from
    scratch!
    

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70. GraphQL Conf 2019
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    Use Case Based, Curated API
    

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71. GraphQL Conf 2019
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    Really need a distributed schema?
    

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72. GraphQL Conf 2019
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    •Make sure you're not designing your API according to how your
    services are split up.
    
    •Dynamic / runtime "stitching" is scary, proceed with care.
    
    •Consider statically building a gateway from a distributed schema
    using tooling as a middle of the road approach.
    

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73. GraphQL Conf 2019
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    The GraphQL Gateway of my
    dreams
    

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74. GraphQL Conf 2019
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    •Configuration based / make it hard to do the wrong thing.
    
    •Thinest layer achievable
    
    •The API Gateway is "just" another service.
    
    •If distributed schemas are necessary, make it easy to "import" them into the gateway.
    
    •However, the gateway schema is its own thing that represents the source of truth for
    our exposed API. It requires
    
    •Resolution is done through your service communication of choice.
    

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75. GraphQL Conf 2019
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    Often a tradeoff between
    development & operational
    complexity
    

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76. GraphQL Conf 2019
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    Alternative: Make developer
    experience great by building tooling
    and best practices
    

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77. GraphQL Conf 2019
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    300+ Contributors to GitHub's
    GraphQL Schema
    

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78. GraphQL Conf 2019
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    Megabytes of schema definitions
    

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79. GraphQL Conf 2019
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    Multiple teams working on one
    schema has not been the hard part
    

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80. GraphQL Conf 2019
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    It is very hard to operate a large
    GraphQL schema at scale, even as a
    single schema
    

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81. GraphQL Conf 2019
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    GraphQL has all we need to build a
    great aggregator or gateway!
    

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82. GraphQL Conf 2019
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    Before choosing a solution, ask
    yourself if the schema itself needs to
    be distributed
    

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83. Thank you
    Come see me after the talk!
    

    or

    @__xuorig__ on Twitter
    

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