Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Building Adaptive Systems

06f8b41980eb4c577fa40c41d5030c19?s=47 Chris Keathley
May 28, 2020
Programming
20
760

Building Adaptive Systems

06f8b41980eb4c577fa40c41d5030c19?s=128

Chris Keathley

May 28, 2020
Tweet

More Decks by Chris Keathley

See All by Chris Keathley
06f8b41980eb4c577fa40c41d5030c19?s=48 keathley
2
350
06f8b41980eb4c577fa40c41d5030c19?s=48 keathley
1
560
06f8b41980eb4c577fa40c41d5030c19?s=48 keathley
5
900
06f8b41980eb4c577fa40c41d5030c19?s=48 keathley
4
740
06f8b41980eb4c577fa40c41d5030c19?s=48 keathley
0
210
06f8b41980eb4c577fa40c41d5030c19?s=48 keathley
0
69
06f8b41980eb4c577fa40c41d5030c19?s=48 keathley
0
290
06f8b41980eb4c577fa40c41d5030c19?s=48 keathley
0
150
06f8b41980eb4c577fa40c41d5030c19?s=48 keathley
2
250

Other Decks in Programming

See All in Programming
C766fe58109bc3750d333f4835ba43c2?s=48 emberconf
0
130
A760a90c9afd981004343b9861f1e8b4?s=48 daipresents
0
280
8a43d544df4886ea5ef714e78f3420a7?s=48 chimerast
0
320
077e9a0cb34fa3eba2699240c9509717?s=48 andrewgodwin
1
150
02ca2dc42e6d88c692a21b18200796a1?s=48 shun_oshidari
6
2.8k
F0a8d07597a19192791bf663504d2a17?s=48 atamaplus
2
420
7eca3e06edc3c69004aaf57de51900c2?s=48 ajstarks
2
410
15934fa2aa7b2ce21f091e9b7cffa856?s=48 manfredsteyer
PRO
0
270
993ef638264def4334358f986fb4a91d?s=48 uhyo
19
9.1k
0063efb4c7066273b877fdabcdcd15b3?s=48 dora1998
0
160
D3edd53371e9150d3ea1c77deef77abf?s=48 nerocrux
2
680
E83cdc415df47ab3eae30957ae7e2d33?s=48 ykpythemind
0
130

Featured

See All Featured
0bce06bd06ee7a2c4f5500f25dcf7f18?s=48 paulrobertlloyd
72
1.5k
027d1ebf66cc039a0bd3b55eeadbe75d?s=48 sachag
267
17k
9128d500301ae51524e887bb680f471d?s=48 caitiem20
311
17k
F716e5f737fcfb03f2cf8d1a184f1dbe?s=48 nonsquared
81
3.4k
A415db3ac9e9668acbc1fb36eead84ac?s=48 mthomps
38
2.3k
A9704266587836f7e784235e5073b93e?s=48 jmmastey
10
690
1519587b1a0febb658c36c94f6272b0d?s=48 roundedbygravity
242
21k
F29327647a9cff5c69618bae420792ea?s=48 tenderlove
53
3.5k
5f83ef806155b403c3393160ce51f955?s=48 jlugia
217
16k
11c84dff30266b907714802088852677?s=48 jasonvnalue
81
8.1k
E76911cbe088e5b850d966de3fc7435b?s=48 robhawkes
52
2.9k
C9b18d9dff88a9dd2393364c2b3b21bd?s=48 colly
66
3k

Transcript

  1. Chris Keathley / @ChrisKeathley / c@keathley.io Building Adaptive Systems

  2. Server Server

  3. Server Server I have a request

  4. Server Server

  5. Server Server

  6. Server Server No Problem!

  7. Server Server

  8. Server Server Thanks!

  9. Server Server

  10. Server Server I have a request

  11. Server Server

  12. Server Server

  13. Server Server I’m a little busy

  14. Server Server I’m a little busy I have more requests!

  15. Server Server I’m a little busy I have more requests!

  16. Server Server I’m a little busy I have more requests!

  17. Server Server I’m a little busy I have more requests!

  18. Server Server I’m a little busy I have more requests!

  19. Server Server I’m a little busy I have more requests!

  20. Server Server I’m a little busy I have more requests!

  21. Server Server I’m a little busy I have more requests!

  22. Server Server I don’t feel so good

  23. Server

  24. Server Welp

  25. Server Welp

  26. All services have objectives

  27. A resilient service should be able to withstand a 10x

    traffic spike and continue to meet those objectives

  28. Lets Talk About… Queues Overload Mitigation Adaptive Concurrency

  29. Lets Talk About… Queues Overload Mitigation Adaptive Concurrency

  30. What causes overload?

  31. What causes overload? Server Queue

  32. What causes overload? Server Queue Processing Time Arrival Rate >

  33. Little’s Law Elements in the queue = Arrival Rate *

    Processing Time

  34. Little’s Law Server 1 requests = 10 rps * 100

    ms 100ms

  35. Little’s Law Server 1 requests = 10 rps * 100

    ms 100ms

  36. Little’s Law Server 1 requests = 10 rps * 100

    ms 100ms

  37. Little’s Law Server 2 requests = 10 rps * 200

    ms 200ms

  38. Little’s Law Server 2 requests = 10 rps * 200

    ms 200ms

  39. Little’s Law Server 2 requests = 10 rps * 200

    ms 200ms

  40. Little’s Law Server 2 requests = 10 rps * 200

    ms 200ms

  41. Little’s Law Server 2 requests = 10 rps * 200

    ms 200ms

  42. Little’s Law Server 2 requests = 10 rps * 200

    ms 200ms BEAM Processes

  43. Little’s Law Server 2 requests = 10 rps * 200

    ms 200ms BEAM Processes CPU Pressure

  44. Little’s Law Server 3 requests = 10 rps * 300

    ms 300ms BEAM Processes CPU Pressure

  45. Little’s Law Server 30 requests = 10 rps * 3000

    ms 3000ms BEAM Processes CPU Pressure

  46. Little’s Law Server 30 requests = 10 rps * ∞

    ms ∞ BEAM Processes CPU Pressure

  47. Little’s Law 30 requests = 10 rps * ∞ ms

  48. Little’s Law ∞ requests = 10 rps * ∞ ms

  49. Little’s Law ∞ requests = 10 rps * ∞ ms

    This is bad

  50. Lets Talk About… Queues Overload Mitigation Adaptive Concurrency

  51. Lets Talk About… Queues Overload Mitigation Adaptive Concurrency

  52. Overload Arrival Rate > Processing Time

  53. Overload Arrival Rate > Processing Time We need to get

    these under control

  54. Load Shedding Server Queue Server

  55. Load Shedding Server Queue Server Drop requests

  56. Load Shedding Server Queue Server Drop requests Stop sending

  57. Autoscaling

  58. Autoscaling

  59. Autoscaling Server DB Server

  60. Autoscaling Server DB Server Requests start queueing

  61. Autoscaling Server DB Server Server

  62. Autoscaling Server DB Server Server Now its worse

  63. Autoscaling needs to be in response to load shedding

  64. Circuit Breakers

  65. Circuit Breakers

  66. Circuit Breakers Server Server

  67. Circuit Breakers Server Server

  68. Circuit Breakers Server Server Shut off traffic

  69. Circuit Breakers Server Server

  70. Circuit Breakers Server Server I’m not quite dead yet

  71. Circuit Breakers are your last line of defense

  72. Lets Talk About… Queues Overload Mitigation Adaptive Concurrency

  73. Lets Talk About… Queues Overload Mitigation Adaptive Concurrency

  74. We want to allow as many requests as we can

    actually handle
  75. None

  76. Adaptive Limits Time Concurrency

  77. Adaptive Limits Actual limit Time Concurrency

  78. Adaptive Limits Actual limit Dynamic Discovery Time Concurrency

  79. Load Shedding Server Server

  80. Load Shedding Server Server Are we at the limit?

  81. Load Shedding Server Server Am I still healthy?

  82. Load Shedding Server Server

  83. Load Shedding Server Server Update Limits

  84. Adaptive Limits Time Concurrency Increased latency

  85. Latency Successful vs. Failed requests Signals for Adjusting Limits

  86. Additive Increase Multiplicative Decrease Success state: limit + 1 Backoff

    state: limit * 0.95 Time Concurrency

  87. Prior Art/Alternatives https://github.com/ferd/pobox/ https://github.com/fishcakez/sbroker/ https://github.com/heroku/canal_lock https://github.com/jlouis/safetyvalve https://github.com/jlouis/fuse

  88. Regulator https://github.com/keathley/regulator

  89. Regulator.install(:service, [ limit: {Regulator.Limit.AIMD, [timeout: 500]} ]) Regulator.ask(:service, fn ->

    {:ok, Finch.request(:get, "https://keathley.io")} end) Regulator

  90. Conclusion

  91. Queues are everywhere

  92. Those queues need to be bounded to avoid overload

  93. If your system is dynamic, your solution will also need

    to be dynamic

  94. Go and build awesome stuff

  95. Thanks Chris Keathley / @ChrisKeathley / c@keathley.io