Scaling WordPress With Load Testing

Everybody wants their site to be scalable. From shared hosting customers to large media companies on expensive dedicated hardware, people deserve to get every last bit of performance that they’ve paid for.

However, most people don’t even bother to load test their sites. And of those who do, a number tend to only run basic tests on their local machine. To truly understand what you can reasonably expect, you need to throw real traffic (and real scenarios) at your production environment.

In this session, we will discuss how to generate tests that mimic realistic user traffic, ways to run these tests against your site, and what to do after you realize things maybe aren’t as fast as you’d thought.

Transcript

1. Scaling WordPress
   With Load Testing
   https://boogah.org/wcsac16
   

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2. Let's talk about
   performance testing
   

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3. Why load test?
   

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4. Common styles of
   performance testing
   

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5. Stress testing
   

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6. Spike testing
   

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7. Endurance testing
   

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8. Configuration testing
   

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9. YMMV
   

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10. Tools
    

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11. ApacheBench
    

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12. ApacheBench Gotchas
    » Single threaded.
    » Not good for benchmarking high capacity servers.
    » Works best when run from the same server as your site.
    » Can only hit one URL at a time.
    » Not much actionable data.
    » Not a real browser test.
    » No HTTP/2 support.
    

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13. Using ApacheBench
    ab -n 100 -c 10 https://jasoncosper.com/
    Translation: Have ApacheBench send 100 requests to my site.
    There should be no more than 10 requests running concurrently.
    

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14. ApacheBench Output
    Server Software: nginx
    Server Hostname: jasoncosper.com
    Server Port: 443
    SSL/TLS Protocol: TLSv1.2,ECDHE-RSA-AES256-GCM-SHA384,4096,256
    Document Path: /
    Document Length: 31927 bytes
    Concurrency Level: 10
    Time taken for tests: 34.163 seconds
    Complete requests: 100
    Failed requests: 0
    Total transferred: 3253000 bytes
    HTML transferred: 3192700 bytes
    Requests per second: 2.93 [#/sec] (mean)
    Time per request: 3416.350 [ms] (mean)
    Time per request: 341.635 [ms] (mean, across all concurrent requests)
    Transfer rate: 92.99 [Kbytes/sec] received
    Connection Times (ms)
    min mean[+/-sd] median max
    Connect: 244 259 18.5 253 343
    Processing: 483 3015 2104.7 2566 11495
    Waiting: 479 3011 2104.9 2564 11491
    Total: 754 3274 2105.9 2813 11766
    Percentage of the requests served within a certain time (ms)
    50% 2813
    66% 3673
    75% 4369
    80% 4677
    90% 6319
    95% 7818
    98% 9886
    99% 11766
    100% 11766 (longest request)
    

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15. If you have macOS
    you have ApacheBench
    

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16. Installing ApacheBench
    If you're using Ubuntu to do your development work:
    apt install apache2-utils
    

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17. h2load
    

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18. h2load > ApacheBench
    » HTTP/2 and HTTP/1.1 support out-of-the-box!
    » It's multithreaded!
    » Support for more than one URL!
    

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19. h2load Gotchas
    » Limited actionable data.
    » Not a real browser test.
    » Best run from the same server as your site.
    

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20. Using h2load
    h2load -n1000 -c100 -m10 https://jasoncosper.com/ https://jasoncosper.com/podcasts/
    Translation: Have h2load send 500 requests to two URLs with
    100 concurrent clients. And please don't go over 10 concurrent
    streams.
    

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21. h2load Output
    starting benchmark...
    spawning thread #0: 100 total client(s). 500 total requests
    TLS Protocol: TLSv1.2
    Cipher: ECDHE-RSA-AES256-GCM-SHA384
    Server Temp Key: ECDH P-256 256 bits
    Application protocol: h2
    finished in 100.52s, 4.97 req/s, 143.56KB/s
    requests: 500 total, 500 started, 500 done, 500 succeeded, 0 failed, 0 errored, 0 timeout
    status codes: 500 2xx, 0 3xx, 0 4xx, 0 5xx
    traffic: 14.09MB (14776906) total, 208.11KB (213106) headers (space savings 21.04%), 13.86MB (14531900) data
    min max mean sd +/- sd
    time for request: 442.43ms 100.21s 42.23s 26.80s 61.80%
    time for connect: 236.00ms 301.97ms 268.62ms 19.25ms 63.00%
    time to 1st byte: 678.74ms 46.08s 13.66s 9.60s 69.00%
    req/s : 0.05 0.12 0.07 0.02 74.00%
    

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22. Installing h2load
    https://boogah.org/inst-h2load
    

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23. JMeter
    

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25. Apache JMeter
    » Created to test production web apps.
    » Ridiculously configurable and extendable.
    » Cross-platform (Mac, Windows, Linux)
    » Fully multithreaded.
    » GUI and CLI.
    » Distributed remote testing support.
    

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26. Installing JMeter
    https://boogah.org/inst-jmeter
    

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27. Creating test plans
    is easyish
    

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28. Don't test production environments
    from your laptop
    

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29. Flood IO
    https://flood.io/
    

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30. BlazeMeter
    https://www.blazemeter.com/
    

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31. Real world
    scenarios
    

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32. Google Analytics
    is your friend
    

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34. Useful Filters
    » ?s
    » product
    » category
    » tag
    

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35. Bringing it
    all together
    

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36. WooCommerce Test Plans
    » Browse site.
    » Browse site, perform multiple searches.
    » Add products to cart, check out.
    » Log in, browse site.
    » Log in, visit "My Account" page.
    » Log in, add products to cart, check out.
    

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37. YMMV
    

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38. Okay, but
    how many users?
    

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39. Push it
    to the limit
    

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40. My limit
    seems kinda low
    

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41. Questions?
    

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42. @boogah
    https://jasoncosper.com/
    https://hipsum.co/
    

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