Solid Ground

Empex, 2017

Transcript

1. Solid ground @sasajuric aircloak.com
2. pattern matching OTP metaprogramming mix Distillery the pipe operator Cowboy Plug Phoenix Ecto functional programming community GenStage Credo ExUnit Combine Poolboy Nerves
4. LFE Erlang OTP BEAM Elixir Phoenix GenStage Ecto Plug magic source magic beneficiaries Cowboy Poolboy
5. long-running system many tasks soft real-time finite time program all-or-nothing hard real-time
6. scheduler scheduler scheduler scheduler BEAM CPU CPU CPU CPU
7. frequent context switches
8. t1 t2 t3 t4 t5 10 s 1 ms 1 ms 1 ms 1 ms
9. t1 BEAM scheduler t2 t3 t4 t5 t1
10. t1 cooperative scheduler t2 t3 t4 t5
11. thread 1 thread n long running task long running task blocked cooperative scheduler …
12. thread 1 thread n long running task long running task BEAM scheduler … not blocked :-)
13. activities as runtime citizens
14. send(pid, :please_stop)
15. mref = Process.monitor(pid) send(pid, :please_stop) receive do {:DOWN, ^mref, :process, ^pid, _reason} -> :ok end
16. mref = Process.monitor(pid) send(pid, :please_stop) receive do {:DOWN, ^mref, :process, ^pid, _reason} -> :ok after :timer.seconds(5) -> Process.exit(pid, :kill) receive do {:DOWN, ^mref, :process, ^pid, _reason} -> :ok end end
17. task = Task.async(fn -> ... end) case Task.yield(task, :timer.seconds(5)) do {:ok, result} -> do_something(result) nil -> Task.shutdown(task, :brutal_kill) end
18. shared-nothing concurrency
19. Process heap resources
20. process-owned “stuff” is released
21. supervision tree
22. system backend frontend chat history repo cache endpoint
23. system backend chat history repo
24. supervisor foundations frequent context switching activities as runtime citizens observable process termination stoppable processes shared-nothing concurrency
25. syntax developer friendliness ecosystem
26. runtime 
 guarantees syntax developer friendliness ecosystem
27. Scales of Justice image taken from clipartfox.com How Erlang does scheduling http://jlouisramblings.blogspot.hr/2013/01/how-erlang-does-scheduling.html Erlang scheduler details https://hamidreza-s.github.io/erlang/scheduling/real-time/preemptive/migration/ 2016/02/09/erlang-scheduler-details.html The BEAM book https://github.com/happi/theBeamBook BEAM wisdoms http://beam-wisdoms.clau.se/en/latest/ Web based observer https://github.com/shinyscorpion/wobserver Recon http://ferd.github.io/recon/ Erlang performance lab http://www.erlang.pl/