TBD

Closing day talk I gave at RubyC in Kiev: http://rubyc.eu/

Further read:
- The Flame Graph: http://queue.acm.org/detail.cfm?id=2927301
- flamegraph gem: https://github.com/SamSaffron/flamegraph
- rack-mini-profiler: https://github.com/MiniProfiler/rack-mini-profiler
- ruby-prof-flamegraph: https://github.com/oozou/ruby-prof-flamegraph

Transcript

1. @mr_foto If you can read this you’re too close TBD
2. TO BE DETERMINED T B D @mr_foto
3. TO BE DETERMINED T B D
7. [YOU] [PARTY]
8. WHOIS ! Software Developer
9. WHOIS ! Software Developer " Ruby Slovenia organizer
10. WHOIS ! Software Developer " Ruby Slovenia organizer # Long Distance Runner
11. WHOIS ! Software Developer " Ruby Slovenia organizer # Long Distance Runner $ Event Photographer
12. WHOIS ! Software Developer " Ruby Slovenia organizer # Long Distance Runner $ Event Photographer ☕ Coffee Connoisseur
13. WHOIS ! Software Developer " Ruby Slovenia organizer # Long Distance Runner $ Event Photographer ☕ Coffee Connoisseur & Special
14. FLAME GRAPHS
15. WHY AND WHAT • How SW is consuming CPU • DTrace is verbose and unreadable • Brendan Gregg • combine stack traces with common paths
19. FLAME GRAPHS EXPLAINED • each box represents a function (a merged stack frame) • y-axis (vertical) shows stack depth • top function led directly to the profiling event • everything beneath it is ancestry (explains why) • x-axis (horizontal) shows the sample sorted alphabetically • box width shows the total time it was on-CPU
20. MOAR EXPLAINING Function
21. MOAR EXPLAINING Function
22. MOAR EXPLAINING Stack Depth
23. MOAR EXPLAINING Stack Depth
24. MOAR EXPLAINING Stack Depth
25. MOAR EXPLAINING Ordered by Alphabet
26. MOAR EXPLAINING Total Time on CPU
27. MOAR EXPLAINING Total Time on CPU
28. Q&A Q: Which function is on CPU the most?
29. Q&A A: f() top edge shows what is on CPU directly
30. Q&A Q: Why is f() on CPU?
31. Q&A A: a() → b() → c() → e() → f() f() was called by e(), e() was called by c(),…
32. Q&A Q: How does b() compare to g()?
33. Q&A A: b() looks like it is running (present) about 10 times more often than g()
34. Q&A Q: Why are we running f()?
35. Q&A A: code path branches can reveal key functions:
 a() choose the b() path
 c() choose the e() path look for branches
36. FOR REAL
37. REAL WORLD EXAMPLE • Sam Saffron • gem 'flamegraph' Flamegraph.generate(filename) do # your work here end
38. 1.083 (± 0.0%) i/s - 33.000 in 30.861265s ORIGINAL
39. 8.368 (±12.0%) i/s - 244.000 in 30.037836s | 7.5x improvement CACHE KRAMDOWN
40. 10.140 (± 9.9%) i/s - 292.000 in 30.025553s | 9.4x improvement MEMOIZATION & CO.
41. FURTHER READ • The Flame Graph
 http://queue.acm.org/detail.cfm?id=2927301 • flamegraph gem
 https://github.com/SamSaffron/flamegraph • rack-mini-profiler
 https://github.com/MiniProfiler/rack-mini-profiler • ruby-prof-flamegraph
 https://github.com/oozou/ruby-prof-flamegraph
43. http://mr.si/
 @mr_foto THANK YOU http://rug.si/
 @RubySlovenia