Erik Webb discusses key considerations for load testing Drupal 8 websites, including that users do not need to know it is built with Drupal, the importance of testing different user paths and backend operations, new caching features in Drupal 8, and ensuring load tests accurately model expected traffic patterns rather than simply extrapolating results. Load testing is important to evaluate a site's performance and scalability under varying user loads.

1. Load Testing & Drupal 8
Erik Webb
Manager, Cloud Engineering
@erikwebb

2. About Me
Joined Acquia in 2010
Manage Acquia Cloud core
platform team
Former Performance Lead,
Professional Services

3. So What’s New?

5. Your users don’t know it’s Drupal 8.

6. Your users don’t know it’s Drupal 8.
Why should your load test?

7. Performance Terminology

8. Performance
GET
drupal.org

9. Scalability
1s ~1s

10. Scaling
Vertical
Horizontal

11. Load Testing
10 users
100 users

12. Stress Testing
??? users

13. Contention
/latest-news

14. So you tested your homepage?
Source: https://www.flickr.com/photos/striatic/2135057566/

15. So you tested your homepage?
Source: https://www.flickr.com/photos/striatic/2135057566/

16. Testing User Paths
User Checkout
User A logs in.
User A visits product page X.
User A adds product X to their
shopping cart.
User A visits their shopping cart.
User A enters payment information.
User A completes transaction.
User Search
User B visits the homepage.
User B enters “product X” into
the search box.
User B views search results
page.
User B clicks on a random
search result.

17. Traffic Breakdown

18. Traffic Breakdown

19. Traffic Breakdown

20. Traffic Breakdown

21. Backend Operations
Does saving content affect performance?
What affect does a deployment have on live traffic?
Do cron jobs affect web traffic?
Background content sync
External web services

22. New “Side Effects” in Drupal 8
Headless Drupal
Caching by default
Cache tags
Service containers
We don’t know yet.
Source: https://www.flickr.com/photos/27762949@N00/33602814/

23. Calculating Traffic

24. Request Fuzzy Math
Number of Threads/Workers
Ramp-up Period
Iterations
Expected Max Concurrency =
Total Requests
Avg. Response Time × Test Length

25. Throughput Shaping Timer
Simply provide requests per
second for each time period
Matches how traffic is usually
measured
jmeter-plugins.org
Supported by Blazemeter

26. Don’t extrapolate results.
150$connections
50$conns 50$conns 50$conns
150$connections

27. Don’t extrapolate results.
300#connections
100#conns 100#conns 100#conns
300#connections
150$connections
50$conns 50$conns 50$conns
150$connections

28. Don’t extrapolate results.
300#connections
50#conns 50#conns 50#conns
300#connections
50#conns 50#conns 50#conns
300#connections
100#conns 100#conns 100#conns
300#connections
150$connections
50$conns 50$conns 50$conns
150$connections

29. Questions?