Profile & Analyze Node.js Applications

Workshop + Node+JS Interactive 2019

Transcript

1. D E C E M B E R 1 5 , 2 0 1 9 Workshop: Profile & Analyze Node.js applications Workshop
2. Giovanny gio@nodesource.com @gioyik
3. © 2019 NodeSourc e What you expect?
4. © 2019 NodeSourc e What is this really?
5. © 2019 NodeSourc e Who had a performance issue with a Node.js application before?
6. © 2019 NodeSourc e let’s be honest now… two at least
7. © 2019 NodeSourc e ok, this time for real, three times that you admit, we don’t judge
8. © 2019 NodeSourc e Asking yourself real questions:
9. © 2019 NodeSourc e Asking yourself real questions: • Why is it slow?
10. © 2019 NodeSourc e Asking yourself real questions: • Why is it slow? • Why it did crash?
11. © 2019 NodeSourc e Asking yourself real questions: • Why is it slow? • Why it did crash? • Was a bad architecture decision?
12. © 2019 NodeSourc e Asking yourself real questions: • Why is it slow? • Why it did crash? • Was a bad architecture decision? • What am I going to do with my life?
13. © 2019 NodeSourc e Asking yourself real questions: • Why is it slow? • Why it did crash? • Was a bad architecture decision? • What am I going to do with my life? • Should I start reviewing my resume again?
14. © 2019 NodeSourc e Asking yourself real questions: • Why is it slow? • Why it did crash? • Was a bad architecture decision? • What am I going to do with my life? • This didn’t happen in PHP, should I go back to Java?
15. © 2019 NodeSourc e What could happen?
16. © 2019 NodeSourc e Bottlenecks
17. © 2019 NodeSourc e Detect what’s the bottleneck
18. © 2019 NodeSourc e Collect metrics and locate bottlenecks
19. © 2019 NodeSourc e Sample profiling to narrow down the general problem area
20. © 2019 NodeSourc e Isolate the exact area
21. © 2019 NodeSourc e What you should know before we start?
22. © 2019 NodeSourc e Event Loop
23. © 2019 NodeSourc e No parallelism in the Event Loop
24. © 2019 NodeSourc e So, what about workers?
25. © 2019 NodeSourc e https://nodejs.org/en/docs/guides/ event-loop-timers-and-nexttick/
26. © 2019 NodeSourc e https://nodejs.org/en/docs/guides/ dont-block-the-event-loop/
27. © 2019 NodeSourc e Profiling
28. © 2019 NodeSourc e CPU
29. © 2019 NodeSourc e perf
30. © 2019 NodeSourc e Dtrace
31. © 2019 NodeSourc e Flamegraphs
32. © 2019 NodeSourc e The more strong/bold/intense the color in the flamegraph piece, the more unoptimized.
33. © 2019 NodeSourc e 0x
34. © 2019 NodeSourc e Don’t use v8-profiler package
35. © 2019 NodeSourc e Memory
36. © 2019 NodeSourc e Why?
37. © 2019 NodeSourc e How GC works: • Root R
38. © 2019 NodeSourc e How GC works: • Root. • Object. R O O O O
39. © 2019 NodeSourc e How GC works: • Root. • Object. • Primitives. R O O O O P P
40. © 2019 NodeSourc e How GC works: • Root • Object. • Primitives. • Non referenced object. R O O O O P P O P
41. © 2019 NodeSourc e Memory scheme (v8): • Resident Set R E S I D E N T S E T
42. © 2019 NodeSourc e Memory scheme (v8): • Resident Set • Code Segment R E S I D E N T S E T C O D E S E G M E N T
43. © 2019 NodeSourc e Memory scheme (v8): • Resident Set • Code Segment • Stack R E S I D E N T S E T C O D E S E G M E N T S TA C K
44. © 2019 NodeSourc e Memory scheme (v8): • Resident Set • Code Segment • Stack • Heap R E S I D E N T S E T C O D E S E G M E N T S TA C K H E A P
45. © 2019 NodeSourc e Memory scheme (v8): • Resident Set • Code Segment • Stack • Heap • Used heap R E S I D E N T S E T C O D E S E G M E N T S TA C K H E A P R S S 
 H E A P TO TA L 
 H E A P U S E D 
 E X TE RN A L
46. © 2019 NodeSourc e Relation between GC and a memory leak? • Impossible to remove non referenced data. • Portion of memory allocated not released when no longer needed.
47. © 2019 NodeSourc e Tooling
48. © 2019 NodeSourc e Chrome DevTools
49. © 2019 NodeSourc e VSCode
50. © 2019 NodeSourc e ndb
51. © 2019 NodeSourc e N|Solid
52. © 2019 NodeSourc e Node clinic
53. © 2019 NodeSourc e Don’t use node-inspector package
54. © 2019 NodeSourc e Why we don’t just break things while we are not in production… yet
55. © 2019 NodeSourc e https://github.com/Gioyik/perf-workshop
56. © 2019 NodeSourc e Exercise #1: Blocking the Event Loop • Create async code and block the event loop • Setup an express endpoint to the event loop operations • Use ab for testing the operation while non and blocked event loop.
57. © 2019 NodeSourc e Exercise #2: Flamegraphs • Run previous event loop exercises with 0x. • Run a simple rest API and observe more details that can appear in the graph
58. © 2019 NodeSourc e Exercise #3: CPU Profiling • Use Tooling to make a CPU Profile • Analyze the data in the CPU profile
59. © 2019 NodeSourc e Exercise #3: Express + Mongodb • Use N|Solid to profile • Simulate a Load and wait for results to analysis
60. © 2019 NodeSourc e Exercise #4: Memory Profiling • Let’s find the memory leak
61. © 2019 NodeSourc e What should you learn next?
62. © 2019 NodeSourc e Recommendations 62
63. © 2019 NodeSourc e I/O operations are… • Expensive. • A waste of resources if your program is unable to do other work. • Usually a hidden operation.
64. © 2019 NodeSourc e Async FTW! Modern applications spend most of their time waiting for I/O
65. © 2019 NodeSourc e Succeed doing I/O operations: • Choose asynchronous over synchronous • Opt for parallel I/O wherever possible • Don't hog the JavaScript thread with long-running calculations and iterations
66. © 2019 NodeSourc e Blocking the Event Loop • Totally possible • Happens more times we want it to happen (who wants to block it in first place?) • Iterations and complex calculations would prevent the process from handling other events
67. © 2019 NodeSourc e so… how good it was?
68. Thank you. Giovanny gio@nodesource.com @gioyik