Messages queues don't need to be scary.

Transcript

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

   to AMQP

2. AMQP

3. Advanced Message
 Queuing Protocol

4. None

5. Why?

6. Job Queue
 Event Stream
 Buffered RPC

7. Job Queue

8. Producer Consumer

9. Producer Consumer Producer

10. Producer Consumer Producer Consumer

11. Producer Consumer Producer Consumer

12. Slow Operations
 Expensive Operations
 Brittle Operations

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 }

14. Acknowledging Messages q = c.queue("task") q.subscribe(worker, ack = TRUE) worker

    = fn(info, metadata, body) { // do work c.acknowledge(info.delivery_tag) }

15. Publishing Options Mandatory Will error if not queued Immediate Will

    error if no consumer available Confirm Server acknowledges receipt

16. Queue Declare Options Passive Don't create, get reference to existing

    queue Durable Queue still exists after a broker restart

17. Event Stream

18. Producer Consumer Producer Consumer Consumer Consumer Producer

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

20. (soft) Real-time updates
 User notifications
 Work distribution

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")

22. Queue Declare Options Exclusive Only one consumer on this queue

    at any time Auto Delete Queue is deleted after consumer disconnects

23. Simulator Demo

24. Buffered RPC

25. Producer Consumer

26. Message Header
 Reply To
 Correlation ID

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

    => "abcdef" }) reply.subscribe(handleResponse)

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

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

29. Smooth out Spikes
 Transparently scale
 Deferred Response

30. Why not just use … ?

31. Delayed Job
 Resque / Sidekiq
 Beanstalkd

32. JMS
 Stomp
 MQTT

33. ØMQ

34. Ruby Quickstart

35. gem install bunny

36. require 'bunny'
 
 url = 'amqp://un:pw@host:5672/vhost'
 conn = Bunny.new(url)
 conn.start


    ch = conn.create_channel
 ch.prefetch 1

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

38. declare_options = {:no_declare => true}
 x = ch.topic("name", declare_options)
 


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