Autoscaling in Kubernetes

Transcript

1. ©2018 Wantedly, Inc. Autoscaling in Kubernetes KubernetesͱΦʔτεέʔϧ ,VCFSOFUFT LT ษڧձ!೔ຊϚΠΫϩιϑτגࣜձࣾ 9.Sep.2018 - Atsushi Tanaka - @bgpat
2. ©2018 Wantedly, Inc. • Atsushi Tanaka ాத
   ಞࢤ
   • Infrastructure Engineer
 at Wantedly, Inc. • Interested in k8s, Docker and Golang About @bgpat
3. ©2018 Wantedly, Inc. Φʔτεέʔϧͷ࿩
4. ©2018 Wantedly, Inc. https://ja.wikipedia.org/wiki/εέʔϥϏϦςΟ "εέʔϧ"
5. ©2018 Wantedly, Inc. https://ja.wikipedia.org/wiki/εέʔϥϏϦςΟ "εέʔϧ"
6. ©2018 Wantedly, Inc. ෛՙʹ߹ΘͤͯࣗಈͰαʔόʔΛ֦ு͢Δ
7. ©2018 Wantedly, Inc. w )PSJ[POUBM
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9. ©2018 Wantedly, Inc. εϖοΫ ୆਺ Scale Out Scale In Scale Down Scale Up
10. ©2018 Wantedly, Inc. w )PSJ[POUBM
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12. ©2018 Wantedly, Inc. w ϝτϦΫε͕ઃఆ஋Λ௒͍͑ͯͳ͍͔؂ࢹ
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    Horizontal Pod Autoscaler
13. ©2018 Wantedly, Inc. /PEF /PEF /PEF Kubernetesͷεέʔϧ 1PE 4FSWJDF 1PE 1PE 1PE 1PE %FQMPZNFOU
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 ϦΫΤετΛϩʔυόϥϯε͢Δ Deployment ͸ Pod ͷ਺Λ
 Ұఆʹอͭ
14. ©2018 Wantedly, Inc. εέʔϧ͢Δج४ w $16࢖༻཰ͷΈ
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    W Horizontal Pod Autoscaler
15. ©2018 Wantedly, Inc. HPA autoscaling/v1
16. ©2018 Wantedly, Inc. HPA autoscaling/v1
17. ©2018 Wantedly, Inc. HPA autoscaling/v1
18. ©2018 Wantedly, Inc. HPA autoscaling/v1
19. ©2018 Wantedly, Inc. autoscaling/v2 ෳ਺ͷϝτϦΫεΛઃఆՄೳ ͲΕ͔ͻͱͭͰ΋ᮢ஋Λ௒͑Δͱεέʔϧ͢Δ • Resource: CPUɾϝϞϦ ͷ࢖༻཰ • Object: Kubernetes ͕؅ཧ͢ΔϦιʔεͷϝτϦΫε • Pods: Pod ʹؔ͢ΔϝτϦΫε • External: Kubernetes ͷϦιʔεʹؔ࿈͠ͳ͍ϝτϦΫε Horizontal Pod Autoscaler
20. ©2018 Wantedly, Inc. HPA autoscaling/v2
21. ©2018 Wantedly, Inc. HPA autoscaling/v2
22. ©2018 Wantedly, Inc. HPA autoscaling/v2
23. ©2018 Wantedly, Inc. HPA autoscaling/v2
24. ©2018 Wantedly, Inc. HPA autoscaling/v2
25. ©2018 Wantedly, Inc. HPA autoscaling/v2
26. ©2018 Wantedly, Inc. API Λ࢖ͬͯϝτϦΫεΛऔಘ͢Δ • Resource Metrics API • Custom Metrics API • External Metrics API Horizontal Pod Autoscaler
27. ©2018 Wantedly, Inc. • Metrics Server or Heapster • Pod Λ Node ʹ഑ஔ͢Δͱ͖ʹ࢖ΘΕΔ • औΕΔϝτϦΫε͸ CPU ͱ ϝϞϦ ͷΈ Resource Metrics API
28. ©2018 Wantedly, Inc. • CPU, ϝϞϦ࢖༻ྔҎ֎ͷϝτϦΫε͕औΕΔ • API αʔόʔΛ༻ҙͯ͠Ϋϥελʹొ࿥͠ͳ͍ͱ͍͚ͳ͍ • Prometheus • Azure • Stackdriver Custom & External Metrics API
29. ©2018 Wantedly, Inc. w )PSJ[POUBM
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30. ©2018 Wantedly, Inc. Pod Λεέδϡʔϧ͢ΔͨΊͷϊʔυ͕଍Γͳ͘ͳΔͱ ΫϥελΛߏ੒͢Δϊʔυͷ਺Λ૿΍͢ ରԠ͍ͯ͠Δ CloudProvider • AWS • Azure • GCP Cluster Autoscaler
31. ©2018 Wantedly, Inc. w )PSJ[POUBM
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32. ©2018 Wantedly, Inc. • Pod ͷਨ௚εέʔϧ • resource.limit ͱ resource.request Λมߋ • Node ΁ͷεέδϡʔϦϯά࣌ʹӨڹ • ᮢ஋͸ࣗಈઃఆ • HPAͱͷซ༻΋Մೳ Vertical Pod Autoscaler
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34. ©2018 Wantedly, Inc. • Pod ͷதʹϦιʔεΛ؂ࢹ͢ΔίϯςφΛཱͯͯ (sidecar)
 ࢖༻ྔʹ߹Θͤͯཁٻ͢ΔϦιʔεΛ૿ݮͤ͞Δ • ૿ݮ͢Δྔ͸ϊʔυͷ਺ʹґଘ • ΫϥελΛߏ੒͢Δίϯϙʔωϯτʹ༻͍ΒΕ͍ͯΔ • cluster-autoscaler • metrics-server Addon Resizer
35. ©2018 Wantedly, Inc. ͔͜͜Βࣄྫ঺հ
36. ©2018 Wantedly, Inc. • kops Ͱ AWS ্ʹߏங • ϊʔυ਺: ໿40୆ • αʔϏε਺: ໿70ݸ • ΞϓϦέʔγϣϯͷ࣮૷ • Ruby on Rails • Goݴޠ • Python (ػցֶश) • C++, Rust (ը૾ॲཧ) WantedlyͷKubernetesΫϥελ
37. ©2018 Wantedly, Inc. • HPA + Custom Metrics • Prometheus • k8s-prometheus-adapter • Prometheus Operator • nginx-exporter • Cluster Autoscaler WantedlyͰ࢖͍ͬͯΔΦʔτεέʔϧ
38. ©2018 Wantedly, Inc. 1SPNFUIFVT 1SPNFUIFVT 1PE 1PE HPA + Custom Metrics ͷߏ੒ .BTUFS
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39. ©2018 Wantedly, Inc. 1SPNFUIFVT 1SPNFUIFVT 1PE 1PE HPA + Custom Metrics ͷߏ੒ .BTUFS
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40. ©2018 Wantedly, Inc. Prometheus Operator https://coreos.com/operators/prometheus/docs/latest/user-guides/getting-started.html
41. ©2018 Wantedly, Inc. Prometheus Operator apiVersion: monitoring.coreos.com/v1 kind: ServiceMonitor metadata: name: service-monitor namespace: custom-metrics labels: service-monitor: prometheus spec: selector: matchLabels: custom-metrics: prometheus namespaceSelector: any: true endpoints: - port: http - port: https custom-metrics: prometheus ͷϥϕϧ͕෇͍͍ͯΔαʔϏε Λ؂ࢹ
42. ©2018 Wantedly, Inc. 1SPNFUIFVT 1SPNFUIFVT 1PE 1PE HPA + Custom Metrics ͷߏ੒ .BTUFS
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43. ©2018 Wantedly, Inc. Nginxͷstub_status location /basic_status { stub_status; } Active connections: 291 server accepts handled requests 16630948 16630948 31070465 Reading: 6 Writing: 179 Waiting: 106 ଴ͪίωΫγϣϯ਺Λ࢖͏
44. ©2018 Wantedly, Inc. Active connections: 291 server accepts handled requests 16630948 16630948 31070465 Reading: 6 Writing: 179 Waiting: 106 nginx-exporter # HELP nginx_connections_current Number of connections currently processed by nginx # TYPE nginx_connections_current gauge nginx_connections_current{state="active"} 2 nginx_connections_current{state="reading"} 0 nginx_connections_current{state="waiting"} 1 nginx_connections_current{state="writing"} 1
45. ©2018 Wantedly, Inc. 1SPNFUIFVT 1SPNFUIFVT 1PE 1PE HPA + Custom Metrics ͷߏ੒ .BTUFS
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46. ©2018 Wantedly, Inc. 1SPNFUIFVT 1SPNFUIFVT 1PE 1PE HPA + Custom Metrics ͷߏ੒ .BTUFS
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47. ©2018 Wantedly, Inc. 1SPNFUIFVT 1SPNFUIFVT 1PE 1PE HPA + Custom Metrics ͷߏ੒ .BTUFS
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48. ©2018 Wantedly, Inc. HPA apiVersion: autoscaling/v2beta1 kind: HorizontalPodAutoscaler metadata: name: wantedly spec: maxReplicas: 50 minReplicas: 20 scaleTargetRef: apiVersion: apps/v1 kind: Deployment name: wantedly metrics: - type: Resource resource: name: cpu targetAverageUtilization: 50 - type: Pods pods: metricName: nginx_connections_current{state="writing"} targetAverageValue: 2.5 CPU ͱ Nginx ͷ
 ଴ͪίωΫγϣϯͰεέʔϧ
49. ©2018 Wantedly, Inc. ΦʔτεέʔϧͱϦΫΤετ਺
50. ©2018 Wantedly, Inc. ΦʔτεέʔϧͱϦΫΤετ਺
51. ©2018 Wantedly, Inc. • αʔόʔͷίετ͕཈͑ΒΕͨ • EC2 30୆ → Pod 20୆ (EC2 7୆෼) • εύΠΫʹڧ͘ͳͬͨ(ؾ͕͢Δ) • Ξϥʔτ͕ݮͬͨ • ᮢ஋ܾΊ͕େม • ௨ৗ࣌ʹΪϦΪϦεέʔϧ͠ͳ͍஋Λ୳͢ KubernetesͷΦʔτεέʔϧΛಋೖͯ͠
52. ©2018 Wantedly, Inc. • KubernetesͰ࢖͑ΔΦʔτεέʔϧͷ࿩ • εέʔϧͷ࢓૊Έ • ઃఆͷ࢓ํ • ࣮ࡍʹ࢖ͬͯΈͨ • ߏ੒ྫ • Ͳ͏ͳ͔ͬͨ ·ͱΊ
53. ©2018 Wantedly, Inc. • Custom Metrics Λಋೖ͢Δ • CPU͚ͩͷͱ͖ΑΓޮ཰Α͘Φʔτεέʔϧ͕࢖͑Δ • ΞϓϦέʔγϣϯͷىಈΛૣ͘͢Δ • ͢͹΍͘εέʔϧͯ͠΋ىಈ͕஗͍ͱεύΠΫʹ͸উͯͳ͍ • API Server ͷΦϓγϣϯΛมߋ͢Δ • --horizontal-pod-autoscaler-sync-period • ϞχλϦϯάͰ͖Δ࢓૊Έ • Wantedly Ͱ͸ DataDog Λ࢖͍ͬͯΔ KubernetesͷΦʔτεέʔϧಋೖͷTips