Netty at Twitter with Finagle

A minimal set of slides used to present an overview of Finagle, an RPC library built atop Netty

Transcript

1. @TwitterAds | Confidential
   Evan Meagher (@evanm)
   7/28/14
   Netty at Twitter with Finagle
   

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2. @Twitter 2
   Agenda
   Why and what is Finagle?
   What does it do?
   What are we working on now?
   

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3. @Twitter 3
   What is Finagle?
   

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4. @Twitter 4
   An open source, protocol-agnostic,
   asynchronous RPC library for the JVM
   

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5. @Twitter 5
   Why did we build Finagle?
   

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6. @Twitter 6
   In the beginning…
   

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7. @Twitter 7
   Monolithic Rails app
   MySQL
   

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8. @Twitter 8
   Monolithic
   Rails app
   MySQL
   Monolithic
   Rails app
   MySQL
   Monolithic
   Rails app
   MySQL
   … Monolithic
   Rails app
   MySQL
   …
   …
   

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9. @Twitter 9
   

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10. @Twitter 10
    

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11. @Twitter 11
    What is Finagle?
    

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12. @Twitter 12
    An open source, protocol-agnostic,
    asynchronous RPC library for the JVM
    

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13. @Twitter 13
    An open source, protocol-agnostic,
    asynchronous RPC library for the JVM
    

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14. @Twitter 14
    An open source, protocol-agnostic,
    asynchronous RPC library for the JVM
    

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15. @Twitter 15
    An open source, protocol-agnostic,
    asynchronous RPC library for the JVM
    

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16. @Twitter 16
    An open source, protocol-agnostic,
    asynchronous RPC library for the JVM
    

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17. @Twitter 17
    What does Finagle do?
    

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18. @Twitter 18
    Standardizes the edges in a “boxes and
    arrows” network diagram
    

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    [1] http://monkey.org/~marius/funsrv.pdf
    

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    type Service[Req, Rep] = Req => Future[Rep]
    

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    type Service[Req, Rep] = Req => Future[Rep]
    Server
    Client
    Req
    Future[Rep]
    

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    A contrived example
    

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    val server = new Service[HttpReq, HttpRep] {
    def apply(req: HttpReq): Future[HttpRep] =
    Future.value(HttpRep(Status.OK, req.body))
    }
    !
    Http.serve(":80", server)
    

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24. @Twitter 24
    val client: Service[HttpReq, HttpRep] =
    Http.newService(“twitter.com:80")
    !
    val futureResponse: Future[HttpRep] =
    client(HttpReq(“/"))
    !
    futureResponse map { response =>
    println(response)
    }
    

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25. @Twitter 25
    Now let’s say you need to
    authenticate requests
    

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    type Service[Req, Rep] = Req => Future[Rep]
    !
    type Filter[Req, Rep] =
    (Req, Service[Req, Rep]) => Future[Rep]
    

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    type Service[Req, Rep] = Req => Future[Rep]
    !
    type Filter[Req, Rep] =
    (Req, Service[Req, Rep]) => Future[Rep]
    Filter Filter Server
    Client
    

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    def isAuthed(req: Req): Boolean
    val authFilter: Filter[HttpReq, HttpRes] = {
    (req, svc) =>
    if (isAuthed(req)) svc(req)
    else Future.exception(new AccessDenied)
    }
    !
    val authedServer: Service[HttpReq, HttpRes] =
    authFilter andThen server
    

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    val instrumentedServer = authFilter
    andThen traceRequest
    andThen recordStats
    andThen server
    

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30. @Twitter 30
    What are we working on now?
    

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    Service discovery
    See the “Names” page on the Finagle user guide:
    http://twitter.github.io/finagle/guide/Names.html
    !
    val client = Http.newService(
    “zk!myzkhost.mycompany.com:2181!/my/zk/path”
    )
    

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    Load balancing
    

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    Request multiplexing
    See the “Protocols” page on the Finagle user guide:
    http://twitter.github.io/finagle/guide/Protocols.html
    

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34. @Twitter 34
    Tail-latency optimization
    

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35. @TwitterAds | Confidential
    Thanks!
    github.com/twitter/finagle
    @finagle
    @evanm
    

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