The key to finding the optimal solution to a problem is to threefold: maximise the number of tools in your ‘personal tool box’; know all their capabilities and uses; and to know which tool is best suited to fix the particular problem in front of you. This talk will enable you to grow all three aspects around load testing. It will look at what it means to ‘load test’ your application, how to get started with writing your first script and provide you with a case study and an insight as to the tools and techniques that we use here at the FT to help identify such performance issues.

1. Ready, Steady, Crash!
Katie Koschland
Engineer, Financial Times
@KKoschland

4. Embarrassed
@KKoschland

5. Could my users be having a
similar experience? ¯_(ツ)_/¯
@KKoschland

6. Hello
@KKoschland

7. I work at the

8. I am going to talk about my
load testing journey.
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9. I will aim to cover the core
concepts behind load
testing.
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10. 1. The Challenge
2. Getting started
3. Identify performance issue
4. Troubleshooting
5. Outcomes
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11. The Challenge
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12. @KKoschland

13. Testing the technical limits
of our node application.
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14. 3 Questions
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15. Will our application crash?
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16. If so, can our application
recover?
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17. What happens to the user
experience?
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18. @KKoschland

19. I was told the answers
could be found by load
testing.
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20. So, what exactly is
load testing ?
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21. @KKoschland
“It is about simulating
ordinary user activity
and then applying
stress until it reaches
failure.”
@Jadware

22. How can I apply this so
called ‘stress’ to my
application?
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23. Choose a
Testing framework
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24. There are many frameworks
out there.
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25. @KKoschland

26. I decided to go with Artillery.
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27. 5 Reasons
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28. @KKoschland

29. Allows you to customise JS
code within your scripts.
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30. @KKoschland

31. Scripts could be configured
using YAML.
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32. @KKoschland

33. Targeted towards
continuous integration.
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34. Provides detailed metrics.
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35. Decide on the type
of requests.
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36. Scripts need to be able to
represent ordinary user
activity.
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37. @KKoschland

38. Decide on the shape
of load.
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39. @KKoschland

40. You may already know the
shape of load.
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41. Before the
release of a push
notification.
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42. @KKoschland

43. But it’s also okay if you don’t
know...
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44. You can split the script into
four separate phases.
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45. Warm Up
Arrival rate of 10 virtual
users/second for 60
seconds.
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46. Ramp up
Arrival rate of 10 to 25 new
virtual users/second for 120
seconds.
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47. Cruise
Arrival rate of 25 virtual
users/second for 1200
seconds.
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48. Crash
Arrival rate of 100 virtual
users/second for 30
seconds.
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49. @KKoschland

50. @KKoschland
Shape of load hitting FT.com
homepage
warm up ramp up Cruise
Crash

51. 1. The challenge
2. Getting started
3. Identify performance issue
4. Troubleshooting
5. Outcomes
@KKoschland

52. What should the
first script look like?
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53. The script is split into two
sections.
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54. Config Section
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55. @KKoschland

56. @KKoschland

57. @KKoschland

58. @KKoschland

59. Scenario Section
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60. @KKoschland

61. @KKoschland

62. @KKoschland

63. Ready to go!
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64. @KKoschland

65. Cool, now what?
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66. Artillery will provide you with a
summary report which
contains detailed metrics.
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67. @KKoschland

68. @KKoschland

69. @KKoschland

70. @KKoschland

71. @KKoschland

72. @KKoschland

73. 1. The Challenge
2. Getting started
3. Identify performance issue
4. Troubleshooting
5. Outcomes
@KKoschland

74. @KKoschland

75. We had
identified a
serious
performance
issue.
@KKoschland

76. 1. The Challenge
2. Getting started
3. Identify performance issue
4. Troubleshooting
5. Outcomes
@KKoschland

77. How do we find
the culprit?
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78. @KKoschland

79. @KKoschland

80. Application issue?
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81. Generate a flamegraph
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82. @KKoschland

83. @KKoschland

84. Neo4j Driver?
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85. @KKoschland

86. @KKoschland

87. Increased the pool size,
decreased the retry timeout.
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88. Parameterized the cypher query
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89. Cypher tuning?
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90. @KKoschland

91. @KKoschland

92. @KKoschland

93. @KKoschland

94. Configuration
issue with db?
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95. @KKoschland

96. @KKoschland

97. So, what was the
fix?
@KKoschland

98. @KKoschland

99. So, why have I shared this
example with you?
@KKoschland

100. Build a
personal
toolbox.
@KKoschland

101. 1. The Challenge
2. Getting started
3. Identify performance issue
4. Troubleshooting
5. Outcomes
@KKoschland

102. Outcomes
@KKoschland

103. Able to measure, assess
and improve the overall
performance of our
application.
@KKoschland

104. Able to assess the
reliability of our application.
@KKoschland

105. To fully understand the
performance and reliability
of what you’re building, you
should all be load testing
your application.
@KKoschland

106. Thanks
@KKoschland

107. We’re hiring!
Visit ft.com/dev/null
@KKoschland