HighLoad++ 2013

1. Mature Optimization
Carlos Bueno <carlos@bueno.org>

2. FACT:
You are not clairvoyant.

4. Who
cares?
Very
obvious!

6. The Plan
1: Measure Carefully.
2: ????
3: Profit!

7. The Plan (revised)
0: Define the Problem.
1: Measure Carefully.
2: ????
3: Profit!

8. Define the Problem.
“WidgetFactoryServer is too slow!”

9. Define the Problem.
“WidgetFactoryServer is too slow!”
Problem definitions must be specific enough
to suggest a way forward, and testable.
You need a falsifiable statement.

10. Define the Problem.
• WidgetFactoryServer is CPU-bound
• Run a profiler
• Optimize the slow functions
• CPU time should decrease

11. FACT:
People have a lot of
advice about writing
fast programs.
Most of it is horseshit.

12. HipHop Virtual Machine (HHVM)
JIT
CPU Time
C++

13. The Plan
0: Define the Problem.
1: Measure Carefully.
2: ????
3: Profit!

14. Measure continuously.

15. Daily & Weekly Cycles

16. Collect RAW data,
not metrics.

17. Record lots of
metadata.

18. Directly measure
what you are
optimizing.

19. Distrust numbers.
Especially your own.

20. “I don’t believe in the
Performance Fairy.”
Jeff Rothschild

21. Monitoring & Investigation
• Crashing is cheap.
• No errors logged, but no data returned.
• Did you buy faster servers?
• Did you turn off slower servers?
• Did some servers just die?

22. Choose metrics
carefully.

23. Questions?
carlos.bueno.org/optimization