Letting Concurrency Help You Today

Ruby has never been renowned for its performance. We choose to love Ruby for its more admirable traits, like simplicity and expressiveness. But it turns out that we can have the best of both worlds by kicking the single-threaded model to the curb and using tried and true concurrency abstractions.

We will take a look at the building blocks Ruby offers for concurrency and how Rubyists have used these to build scalable, performant libraries just dying to be used. You’ll walk away with an understanding of concurrency and how you can leverage it in your applications today.

Transcript

1. LETTING CONCURRENCY HELP YOU TODAY
2. RICHARD BISHOP @rbondev on Twitter Polyglot with a problem Coffee and Craft Beer Nut
3. MYSELF
4. The “Other Side” of Rack
5. AGENDA 1. Concurrency 101 2. Practical Uses 3. Abstractions 4. Ruby!
6. NOT AGENDA 1. Stuffing an Array 2. Bashing the GIL 3. Tour de Runtimes
7. WHY SHOULD I CARE? •Get more out of hardware •Better user experience •Better design (say what?)
8. WARNING OBLIGATORY MEME IN CONFERENCE TALK SLIDES
10. “Concurrency is about dealing with lots of things at once. Parallelism is about doing lots of things at once.” ! - Rob Pike
11. ?
12. A REAL RUBY EXAMPLE PARALLEL ! Example: Threaded or forking web server on multicore. ! No communication between the requests. ! Points of execution overlapping the same time. CONCURRENT ! Example: Batch processing background jobs. ! Communication between jobs or another job ! Multiple points of execution.
13. COMPOSITION & COMMUNICATION
15. MEET THE PRIMITIVES
16. PROCESSES THREADS EVENTS
17. CPU I/O PROCESSES ✓ ✓ THREADS ✓ ✓ EVENTS ✓
18. CPU I/O COMM. PROCESSES ✓ ✓ IPC THREADS ✓ ✓ SHARED MEMORY EVENTS ✓ ??? Ask Node.js
19. Basics Recap • Composition & Communication • Concurrency is structure • Parallelism is execution and time • Processes, Threads, Events
20. LETTING CONCURRENCY THREADS HELP YOU TODAY
21. HISTORY OF HARD PROBLEMS
22. “Memory management is hard”
23. Garbage Collectors
24. “Writing SQL is hard”
25. Query Generators
26. “Threading is hard”
27. ???
28. Why not Processes? • Expensive • Communication is hard • Not easily composed
29. LETS GET PRACTICAL
30. • Actors + Objects • Messages! • Pools & Supervisors Celluloid
31. Celluloid
32. ! ! ! ! class Greeter! !! ! ! include Celluloid! ! !! ! ! def greet(msg)! ! ! ! ! puts msg! !! ! ! end! ! ! ! ! end! ! greeter = Greeter.new! => #<Celluloid::CellProxy(Greeter)>! ! greeter.async! => #<Celluloid::AsyncProxy(Greeter)>! ! greeter.async.greet("Hello, Ruby Conf!”)
33. some_obj.expensive_method ! # wait... wait... wait... Thread.new {! obj.expensive_method! }
34. module Celluloid! class AsyncProxy < AbstractProxy! ! def method_missing(meth, *args, &block)! ! ! ! ...! @mailbox << AsyncCall.new(meth, args, block)! end! end! end!
35. Sidekiq • Multi-threaded • Uses Celluloid
36. Sidekiq
37. Sidekiq Actor Actor Actors!
38. sucker_punch •Very easy to use •In-memory •Also uses Celluloid •Similar API to Sidekiq
39. Puma •Multi-threaded •Forking •Evented
40. Puma
41. @app.call(env)
42. Recap • Abstractions! • Actors & ThreadPool • Libraries we can use today
43. CONCURRENT DESIGN
44. PAIN
45. Elixir • Concurrency as a paradigm • Runs on Erlang VM • Actors & Message Passing
47. Cache Web WebSockets Processing
48. Typical Ruby Architecture
49. ! Web Worker
51. Service Oriented Architecture
53. Repo Oriented Architecture
54. SOA Motivations 1. Forced boundaries 2. Individual scaling
55. We Overestimate 1. Reliability of network 2. Actual decoupling
56. Design Recap • Forced modularity • Scale independently • Messaging is hard • It’s just programming
57. RUBY DEFENDING
58. The 1990s
59. 1990s PL Design Step One Pick a paradigm Step Two Static or dynamic? … Step 185 Slap some POSIX Threads on!*
60. The 2010s
61. 2000s PL Design Step One Choose a concurrency model Step 2-∞ Choose features that compliment step #1
62. PARALLELISM
63. GARBAGE COLLECTOR
64. ABSTRACTIONS
65. Ruby Thread Mutex ConditionVariable Queue Monitor
66. WE LOVE SIMPLE
67. CUTTING EDGE is never SIMPLE
69. THANK YOU
70. Questions?