Messages queues don't need to be scary.

An introduction tutorial to AMQP with RabbitMQ and Ruby.

Transcript

1. Message queues don't
   need to be scary
   An intro workshop to AMQP
   

   View Slide

2. AMQP
   

   View Slide

3. Advanced Message

   Queuing Protocol
   

   View Slide

4. View Slide

5. Why?
   

   View Slide

6. Job Queue

   Event Stream

   Buffered RPC
   

   View Slide

7. Job Queue
   

   View Slide

8. Producer Consumer
   

   View Slide

9. Producer
   Consumer
   Producer
   

   View Slide

10. Producer Consumer
    Producer Consumer
    

    View Slide

11. Producer Consumer
    Producer Consumer
    

    View Slide

12. Slow Operations

    Expensive Operations

    Brittle Operations
    

    View Slide

13. Producer
    c = create_channel
    q = c.queue("task")
    x = c.default_exchange
    x.publish(
    "task",
    "payload"
    )
    Consumer
    c = create_channel
    q = c.queue("task")
    q.subscribe(worker)
    worker = fn(*message)
    {
    // do stuff
    }
    

    View Slide

14. Acknowledging Messages
    q = c.queue("task")
    q.subscribe(worker, ack = TRUE)
    worker = fn(info, metadata, body) {
    // do work
    c.acknowledge(info.delivery_tag)
    }
    

    View Slide

15. Publishing Options
    Mandatory
    Will error if not queued
    Immediate
    Will error if no consumer available
    Confirm
    Server acknowledges receipt
    

    View Slide

16. Queue Declare Options
    Passive
    Don't create, get reference to
    existing queue
    Durable
    Queue still exists after a broker
    restart
    

    View Slide

17. Event Stream
    

    View Slide

18. Producer
    Consumer
    Producer
    Consumer
    Consumer
    Consumer
    Producer
    

    View Slide

19. Topic Exchange
    routing.key
    Exact match
    routing.*.key
    routing.#.key
    Wildcard
    matching
    routing.key
    routing.a.key
    routing.b.key
    routing.a.b.key
    

    View Slide

20. (soft) Real-time updates

    User notifications

    Work distribution
    

    View Slide

21. Binding a Queue
    x = c.exchange("activity”)
    q = c.queue("alert")
    q.bind(x, "balance.*")
    q.bind(x, "transfer.out")
    x.publish("balance.low")
    x.publish("transfer.in")
    x.publish("transfer.out")
    

    View Slide

22. Queue Declare Options
    Exclusive
    Only one consumer on this queue
    at any time
    Auto Delete
    Queue is deleted after consumer
    disconnects
    

    View Slide

23. Simulator Demo
    

    View Slide

24. Buffered RPC
    

    View Slide

25. Producer
    Consumer
    

    View Slide

26. Message Header

    Reply To

    Correlation ID
    

    View Slide

27. Reply To
    reply = c.queue("abcdef")
    x.publish("request", :headers => {
    :replyTo => "abcdef"
    })
    reply.subscribe(handleResponse)
    

    View Slide

28. Correlation ID
    x.publish("request1", :headers => {
    :replyTo => "abcdef",
    :correlationID => "request1"
    })
    x.publish("request2", :headers => {
    :replyTo => "abcdef",
    :correlationID => "request2"
    })
    

    View Slide

29. Smooth out Spikes

    Transparently scale

    Deferred Response
    

    View Slide

30. Why not just
    use … ?
    

    View Slide

31. Delayed Job

    Resque / Sidekiq

    Beanstalkd
    

    View Slide

32. JMS

    Stomp

    MQTT
    

    View Slide

33. ØMQ
    

    View Slide

34. Ruby Quickstart
    

    View Slide

35. gem install bunny
    

    View Slide

36. require 'bunny'

    

    url = 'amqp://un:pw@host:5672/vhost'

    conn = Bunny.new(url)

    conn.start

    ch = conn.create_channel

    ch.prefetch 1
    

    View Slide

37. declare_options = {:no_declare => true}

    q = ch.queue(name, options)

    

    options = {:block => true, :ack => true}

    q.subscribe(options) do |info, meta, body|

    # do stuff

    ch.ack(info.delivery_tag)

    end
    

    View Slide

38. declare_options = {:no_declare => true}

    x = ch.topic("name", declare_options)

    

    x.publish("message", :routing_key => "key")
    

    View Slide