High Availability

ElixirConf Europe

1. iex(1)> high_availability @sasajuric aircloak.com
2. Erlang 
 (the language) Elixir LFE Erlang VM (BEAM)
3. highly_available ≈ works_almost_always
4. optional?(highly_available) # false
5. easy?(highly_available) # false
7. highly_available do # the code here magically works end #doesntworklikethat
8. fault-tolerance scalability + responsiveness = high availability
9. A B D E F C
10. send(pid, message) A B message = receive ...
11. def loop(state) do receive do message -> new_state = handle(state, message) loop(new_state) end end
12. bank account balance {:deposit, amount} {:withdraw, amount} :balance amount
13. OS process or thread Erlang process
14. db connection background job request handler state request handler request handler request handler request handler request handler state state state background job background job background job db connection db connection db connection
15. A B C D E F
16. A exit message B C D E F
17. supervisor worker worker
18. S S S W W S W W W S W W
19. scheduler scheduler scheduler scheduler CPU CPU CPU CPU VM
20. VM VM VM VM VM
21. VM send(pid, message) VM 1 send(pid, message) VM 2
22. shared-nothing concurrency process crash propagation + some VM magic = fault tolerance
 scalability
 responsiveness
24. 3rd party data source transform data push server browsers bets validation
25. Data transformation 1.Receive TCP stream" 2.Assemble XML messages" 3.Update the model" 4.Store to database" 5.Serialize the model" 6.Dispatch
26. receive stream assemble messages update model store to database serialize data dispatch
27. receive stream assemble messages update model store to database serialize data dispatch message 6 message 5 message 4 message 3 message 2 message 1
28. receive stream assemble messages update model store to database serialize data dispatch
29. storing to database queuing bet odds storing bet odds
30. match 1 match 3 match 2
31. update model serialize data dispatch match 1 match 3 match 2