Introduction to Erlang

Presented at the Stockholm Erlang User Group.

Transcript

1. TEXT WHY YOU SHOULD BUILD your next application IN ERLANG
2. TEXT WHEN YOU SHOULD BUILD your next application IN ERLANG
3. ERLANG IS NOT A MAGIC LANGUAGE.
4. USE THE RIGHT TOOL FOR THE RIGHT JOB
5. ERLANG WAS DESIGNED TO HELP YOU WRITING SYSTEMS DISTRIBUTED
6. ERLANG WAS DESIGNED TO HELP YOU WRITING SYSTEMS SCALABLE
7. ERLANG WAS DESIGNED TO HELP YOU WRITING SYSTEMS RELIABLE
8. ERLANG WAS DESIGNED TO HELP YOU WRITING SYSTEMS ROBUST
9. ERLANG WAS DESIGNED TO HELP YOU WRITING SYSTEMS FAULT TOLERANT
10. ERLANG WAS DESIGNED TO HELP YOU WRITING SYSTEMS MASSIVELY CONCURRENT
11. Do you need a distributed system? Do you need a scalable system? Do you need a reliable system? Do you need a fault-tolerant system? Do you need a massively concurrent system? Do you need a distributed system? Do you need a scalable system? Do you need a reliable system? Do you need a fault-tolerant system? Do distributed system? Do you need a scalable system? Do you need a reliable system? Do you need a fault-tolerant system? Do you need a massively NEED ERLANG? DO YOU
12. THEN USE ERLANG.
13. ERLANG IS NOT DIFFICULT TO LEARN - O N C E Y O U G E T PA S T T H E I N I T I A L H E A D A C H E - YOU WON’T BE ABLE TO LIVE WITHOUT IT
14. ERLANG MAKES YOUR LIFE EASIER - N O T T H E O T H E R WAY A R O U N D - HAVE A LOOK TO OTP
15. ERLANG IS ALSO FUN - B U T D O N ’ T T E L L Y O U R B O S S - OR YOU’LL GET PAID LESS
16. WHERE TO START @ r o b e r t o a l o i
18. WHERE TO START LET’S TALK ABOUT ERLANG
19. ... But in Practice? NICE WORDS SCALABILITY ROBUSTNESS FAULT TOLERANCE MASSIVE CONCURRENCY DISTRIBUTION
20. WHERE TO START PROCESSES AND MESSAGE PASSING
21. CREATE (SPAWN) A PROCESS spawn(math, fact, [5]) Pid1 Processes
22. CREATE (SPAWN) A PROCESS spawn(math, fact, [5]) math:fact(5) Pid2 Pid1 Processes
23. AND SEND A MESSAGE TO IT Pid2 Pid1 Pid2 ! {self(),msg} Message Passing
24. AND SEND A MESSAGE TO IT Pid2 Pid1 Pid2 ! {self(),msg} {Pid1,msg} Message Passing
25. LINKS AND EXIT SIGNALS
26. CREATE A BI-DIRECTIONAL LINK BETWEEN PROCESSES Links PidB PidA link(PidB)
27. CREATE A BI-DIRECTIONAL LINK BETWEEN PROCESSES Links PidB PidA link(PidB)
28. PROPAGATING EXIT SIGNALS Exit Signals PidA PidB PidC
29. PROPAGATING EXIT SIGNALS Exit Signals PidA PidB PidC
30. PROPAGATING EXIT SIGNALS Exit Signals PidB {'EXIT', PidA, Reason} PidC
31. PROPAGATING EXIT SIGNALS Exit Signals PidB PidC
32. PROPAGATING EXIT SIGNALS Exit Signals PidC {'EXIT', PidB, Reason}
33. PROPAGATING EXIT SIGNALS Exit Signals
34. Trap Exit TRAPPING AN EXIT SIGNAL PidA PidC PidB
35. Trap Exit TRAPPING AN EXIT SIGNAL PidA PidC PidB
36. Trap Exit TRAPPING AN EXIT SIGNAL {'EXIT', PidA, Reason} PidC PidB
37. Trap Exit TRAPPING AN EXIT SIGNAL PidC PidB
38. SUPERVISORS
39. Supervisors PidA PidC PidB
40. Supervisors PidA PidC PidB
41. Supervisors PidA PidC PidB Supervisor
42. Supervisors PidA PidC PidB Supervisor Workers
43. LET IT CRASH (OR FAIL)
44. Let It Crash convert(Day) -> case Day of monday -> 1; tuesday -> 2; wednesday -> 3; thursday -> 4; friday -> 5; saturday -> 6; sunday -> 7; Other -> {error, unknown_day} end.
45. DISTRIBUTED ERLANG
46. Distributed Erlang erl -sname london erl -sname krakow erl -sname stockholm
47. BEHAVIOURS
48. Behaviours Servers Finite State Machines Event Handlers Supervisors Applications Less Code Less Bugs More Solid Code More Tested Code More Free Time
49. Y U NO SHOW ME CODE!?
50. WHERE TO START DEMO TIME (if it can go wrong, it will)
51. WHO USES ERLANG?
54. WHERE TO START
55. erlang.org github.com/erlang/otp erlang-solutions.com www.learnyousomeerlang.org elearning.erlang-solutions.com Erlang Programming Erlang and OTP in Action Official Home Page Sources Binary Packages, News, Events Best Online Tutorial Commercial e-learning solution Best book about basics Best book about OTP
56. QUESTIONS? @robertoaloi