Celluloid & DCell

Transcript

1. Celluloid
   DCell
   &
   

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2. @vanstee
   github.com/vanstee
   Patrick Van Stee
   highgroove.com
   

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3. @tarcieri
   Revactor
   Reia
   nio4r
   Cryptosphere
   cool.io
   

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4. brew install zeromq
   gem install dcell
   Setup
   

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5. Celluloid
   General purpose concurrency
   framework for Ruby built on the
   Actor Model
   

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6. class Counter
   attr_reader :count
   def initialize
   @count = 0
   end
   def increment
   @count += 1
   end
   end
   

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7. class Counter
   attr_reader :count
   def initialize
   @count = 0
   @mutex = Mutex.new
   end
   def increment
   @mutex.synchronize do
   @count += 1
   end
   end
   end
   

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8. Threads
   are
   hard!
   

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9. class Counter
   include Celluloid
   attr_reader :count
   def initialize
   @count = 0
   end
   def increment
   @count += 1
   end
   end
   

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10. Actor
    Model
    

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11. •No shared state
    •Communicate with
    messages
    •Process messages
    sequentially
    

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12. class Counter
    include Celluloid
    def increment(count, actor)
    return count if count < 10000
    actor.increment(
    count + 1,
    Actor.current
    )
    end
    end
    

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13. &
    Asynchronous
    Method Calls
    Futures
    

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14. counter = Counter.new
    # returns immediately
    counter.increment!
    puts counter.count
    # returns immediately
    future = counter.future :increment
    puts future.value
    

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15. module Enumerable
    def map(&block)
    futures = map do |item|
    Celluloid::Future.new(
    item,
    &block
    )
    end
    futures.map(&:value)
    end
    end
    

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16. Caveats
    

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17. • The GIL in MRI does
    not allow parallelism
    • Threads and Fibers
    are expensive
    • Concurrency is still a
    hard problem
    [not really]
    

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18. DCell
    

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19. Celluloid
    General purpose concurrency
    framework for Ruby built on the
    Actor Model
    DCell
    Distributed Celluloid over 0MQ
    

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20. “I thought of objects being like
    biological cells or individual
    computers on a network, only
    able to communicate with
    messages. Alan Kay
    

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21. • Exposes Actors on the
    Network
    • Send messages as you
    normally would
    

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22. DRb DCell
    Threads Actors
    

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23. Demo
    

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24. Also
    Checkout
    Sidekiq
    

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25. github.com
    celluloid/celluloid
    celluloid/dcell
    

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26. Hack Night
    

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