Introduction to Erlang

Transcript

1. Introduction  to  Erlang Michał  Ślaski          @michalslaski   ! ! !      AKAI  Camp  Backend,  Poznań,  28.10.2014
2. Erlang  timeline  and  my  background
3. Erlang  timeline  and  my  background Started  out  in  the  Ericsson  software  lab  1987  (!)
4. Erlang  timeline  and  my  background Started  out  in  the  Ericsson  software  lab  1987  (!) • I  was  six  years  old

5. Erlang  timeline  and  my  background Started  out  in  the  Ericsson  software  lab  1987  (!) • I  was  six  years  old
 Released  as  open  source  in  1998
6. Erlang  timeline  and  my  background Started  out  in  the  Ericsson  software  lab  1987  (!) • I  was  six  years  old
 Released  as  open  source  in  1998 • I  started  computer  science  at  AGH  2  years  later

7. Erlang  timeline  and  my  background Started  out  in  the  Ericsson  software  lab  1987  (!) • I  was  six  years  old
 Released  as  open  source  in  1998 • I  started  computer  science  at  AGH  2  years  later
 Gains  SMP  support  in  2005
8. Erlang  timeline  and  my  background Started  out  in  the  Ericsson  software  lab  1987  (!) • I  was  six  years  old
 Released  as  open  source  in  1998 • I  started  computer  science  at  AGH  2  years  later
 Gains  SMP  support  in  2005 • I  just  graduated  and  joined  Erlang  Solutions
9. Erlang  properties
10. Erlang  properties Declarative   • Functional  programming  language   • high  abstraction  level   • pattern  matching   • concise  and  readable  programs
11. Erlang  properties  -­‐  functions Modules & Functions -module(demo). -export([double/1]). % This is a comment. % Everything after '%' is ignored. double(X) -> times(X, 2). times(X, N) -> X * N.
12. Erlang  properties
13. Erlang  properties Concurrency   • light-­‐weight  processes  (actor  model)   • highly  scalable
 

14. Erlang  properties Concurrency   • light-­‐weight  processes  (actor  model)   • highly  scalable
 
 Soft  real-­‐time   • response  times  in  the  order  of  milliseconds   • per  process  garbage  collection
15. Erlang  properties  -­‐  processes
16. Erlang  properties  -­‐  processes
17. Erlang  properties  -­‐  processes Pid = spawn(M, F, A)
18. Erlang  properties  -­‐  processes Pid = spawn(M, F, A)
19. Erlang  properties  -­‐  processes Pid = spawn(M, F, A) receive! {msg, From} ->! From ! ok! end
20. Erlang  properties  -­‐  processes Pid = spawn(M, F, A) receive! {msg, From} ->! From ! ok! end Pid ! {msg, self()}
21. Erlang  properties  -­‐  processes Pid = spawn(M, F, A) receive! {msg, From} ->! From ! ok! end Pid ! {msg, self()} ok
22. Erlang  properties Robustness   • simple  and  consistent  error  recovery   • supervision  hierarchies   • program  for  the  correct  case   • let  it  crash
23. Erlang  properties  -­‐  supervision  tree
24. Erlang  properties  -­‐  supervision  tree
25. Erlang  properties  -­‐  supervision  tree
26. Erlang  properties  -­‐  supervision  tree supervisor
27. Erlang  properties  -­‐  supervision  tree supervisor worker
28. Erlang  properties  -­‐  supervision  tree supervisor worker
29. Erlang  properties  -­‐  supervision  tree supervisor worker
30. Erlang  properties  -­‐  supervision  tree supervisor worker
31. Erlang  properties Distribution   • explicit  or  transparent  distribution   • network-­‐aware  runtime  system
32. Erlang  properties  -­‐  distribution
33. Erlang  properties  -­‐  distribution cat
34. Erlang  properties  -­‐  distribution cat flea
35. Erlang  properties  -­‐  distribution cat flea nodes() = [cat@home, flea@home]
36. Erlang  properties  -­‐  distribution cat dog flea bird nodes() = [cat@home, flea@home]
37. Erlang  properties  -­‐  distribution cat dog flea bird nodes() = [cat@home, flea@home] nodes() = [dog@home, bird@home]
38. Erlang  properties  -­‐  distribution cat dog flea bird nodes() = [cat@home, flea@home] nodes() = [dog@home, bird@home]
39. Erlang  properties  -­‐  distribution cat dog flea bird nodes() = [cat@home, flea@home, dog@work, bird@work]
40. Erlang  properties
41. Erlang  properties Hot  code  loading   • easily  change  code  in  a  running  system   • enables  non-­‐stop  operation   • simplifies  testing

42. Erlang  properties Hot  code  loading   • easily  change  code  in  a  running  system   • enables  non-­‐stop  operation   • simplifies  testing
 SMP  support   • takes  advantage  of  multiple  CPU  architectures

43. Erlang  properties Hot  code  loading   • easily  change  code  in  a  running  system   • enables  non-­‐stop  operation   • simplifies  testing
 SMP  support   • takes  advantage  of  multiple  CPU  architectures
 Erlang  Shell   • access  from  remote  nodes
44. Erlang  properties
45. Erlang  properties External  interfaces   • "Ports"  to  the  outside  world
 behave  as  Erlang  processes

46. Erlang  properties External  interfaces   • "Ports"  to  the  outside  world
 behave  as  Erlang  processes
 Portability   • Erlang  runs  on  Unix,  Linux,  Mac  OS  X,  Windows   • RaspberryPi  and  Parallella  
47. Demo  time!
48. Demo  -­‐  SMP $ erl -smp disable Erlang/OTP 17 [erts-6.1] [source-d2a4c20] [async-threads:10]
 [hipe] [kernel-poll:false] ! Eshell V6.1 (abort with ^G) 
 1> F = fun(Int) -> pmap:factorial(Int) end. #Fun<erl_eval.6.90072148>
 2> timer:tc(lists, map, [F,lists:seq(1, 5000)]). {12570092, [1,2,6,24,120,720,5040,40320,362880,3628800|...]} 
 3> timer:tc(pmap, pmap, [F,lists:seq(1, 5000)]). {21511918, [1,2,6,24,120,720,5040,40320,362880,3628800|...]} 
 4> element(2, v(2)) == element(2, v(3)). true
49. Demo  -­‐  SMP $ erl -smp enable Erlang/OTP 17 [erts-6.1] [source-d2a4c20] [smp:4:4]
 [async-threads:10] [hipe] [kernel-poll:false] ! Eshell V6.1 (abort with ^G) ! 1> F = fun(Int) -> pmap:factorial(Int) end. #Fun<erl_eval.6.90072148> ! 2> timer:tc(lists, map, [F,lists:seq(1, 5000)]). {12535610, [1,2,6,24,120,720,5040,40320,362880,3628800|...]} ! 3> timer:tc(pmap, pmap, [F,lists:seq(1, 5000)]). {9159734, [1,2,6,24,120,720,5040,40320,362880,3628800|...]}
50. Demo  -­‐  SMP no  SMP SMP map 12.5s 12.5s parallel   map 21.5s 9.2s
51. Demo  -­‐  SMP no  SMP SMP map 12.5s 12.5s parallel   map 21.5s 9.2s
52. Demo  -­‐  SMP no  SMP SMP map 12.5s 12.5s parallel   map 21.5s 9.2s 230%
53. Open  source  projects
54. Open  source  projects • RabbitMQ  message  broker  

55. Open  source  projects • RabbitMQ  message  broker  
 • MongooseIM  XMPP  server

56. Open  source  projects • RabbitMQ  message  broker  
 • MongooseIM  XMPP  server
 • Riak  database

57. Open  source  projects • RabbitMQ  message  broker  
 • MongooseIM  XMPP  server
 • Riak  database
 • CouchDB  database
58. Erlang  community
59. Erlang  community Erlang  Central   • www.erlangcentral.org

60. Erlang  community Erlang  Central   • www.erlangcentral.org
 Erlang  Factory   • Berlin,  December  4   • San  Francisco,  March  26-­‐27

61. Erlang  community Erlang  Central   • www.erlangcentral.org
 Erlang  Factory   • Berlin,  December  4   • San  Francisco,  March  26-­‐27
 Lambda  Days   • Kraków,  February  26-­‐27
62. Questions? ! Michał  Ślaski          @michalslaski