Performing chaos in a serverless world - Chaos Community Day London September 13 2019

The principles of chaos engineering have been battle-tested for years using traditional infrastructure and containerized microservices, but how do they work with serverless functions and managed services? In this session we'll cover what differs, how we perform chaos experiments and what some of the common weaknesses we can test for in our serverless applications are.

Presented at Chaos Community Day London September 13, 2019.

Transcript

1. @gunnargrosch Performing chaos in a serverless world Gunnar Grosch Chaos Community Day London 2019
2. Chaos Community Day London 2019 @gunnargrosch Chaos Engineering has been battle-tested for years using traditional infrastructure and containerized microservices, but how does it work with serverless functions and managed services?
3. Chaos Community Day London 2019 @gunnargrosch What is serverless? What we’ll cover Challenges for serverless Serverless chaos experiments
4. Chaos Community Day London 2019 @gunnargrosch A resilient system is a highly available and durable system that can maintain an acceptable level of service in the face of failure.
5. Chaos Community Day London 2019 @gunnargrosch About me Evangelist and co-founder at Opsio Background in development and operations Organizer of AWS User Groups and AWS Community Day Nordics ServerlessDays Stockholm and Serverless Meetups organizer Father of three chaos monkeys
6. Chaos Community Day London 2019 @gunnargrosch What is serverless?
7. Chaos Community Day London 2019 @gunnargrosch “Serverless allows you to build and run applications and services without thinking about servers. It eliminates infrastructure management tasks such as server or cluster provisioning, patching, operating system maintenance, and capacity provisioning.” Amazon Web Services
8. Chaos Community Day London 2019 @gunnargrosch ”Stop calling everything serverless” Jeremy Daly
9. Chaos Community Day London 2019 @gunnargrosch Serverless is not an execution model
10. Chaos Community Day London 2019 @gunnargrosch Managed services are not serverless
11. Chaos Community Day London 2019 @gunnargrosch Serverless is not an operational construct or a spectrum
12. Chaos Community Day London 2019 @gunnargrosch Serverless is not a technology
13. Chaos Community Day London 2019 @gunnargrosch Serverless is a methodology
14. Chaos Community Day London 2019 @gunnargrosch
15. Chaos Community Day London 2019 @gunnargrosch Source: HDMI No Signal To display Help, press the ? button
16. Chaos Community Day London 2019 @gunnargrosch “Everything fails, all the time!” Werner Vogels, CTO Amazon Source: HDMI No Signal To display Help, press the ? button
17. Chaos Community Day London 2019 @gunnargrosch Don’t ask what happens if a system fails, but ask what happens when it fails.
18. Chaos Community Day London 2019 @gunnargrosch Challenges for serverless
19. Chaos Community Day London 2019 @gunnargrosch ”There are still servers in serverless” Bob Dylan
20. Chaos Community Day London 2019 @gunnargrosch Serverless is a higher level abstraction
21. Chaos Community Day London 2019 @gunnargrosch “… without thinking about servers.” Amazon Web Services
22. Chaos Community Day London 2019 @gunnargrosch Serverless doesn’t make your application resilient
23. Chaos Community Day London 2019 @gunnargrosch Pros are also cons No servers to manage Less heavy lifting Lots of services to choose from Per function configuration and security More granular architectures
24. Chaos Community Day London 2019 @gunnargrosch Common serverless weaknesses Missing error handling Wrong timeout values Missing fallback Missing regional failover
25. Chaos Community Day London 2019 @gunnargrosch Serverless chaos experiments
26. Chaos Community Day London 2019 @gunnargrosch Serverless chaos experiments • Inject errors in your code • One in X requests throws an error • Turn on and off using parameter or variable • Remove downstream services • Alter the concurrency of your functions • Restrict the capacity of your DynamoDB table • Add configuration errors • Security policies • CORS configuration • Function disk space failures
27. Chaos Community Day London 2019 @gunnargrosch Serverless chaos experiments • Add latency to your functions • Cold starts • Cloud provider issues • Runtime or code issues • Integration issues • Timeouts • Yan Cui wrote an article and published sample code. • Adrian Hornsby built a Lambda Layer around these ideas (and now a Python library).
28. Chaos Community Day London 2019 @gunnargrosch Tools for serverless chaos experiments Gremlin gremlin.com Chaos Toolkit chaostoolkit.org Thundra thundra.io Build Your Own 127.0.0.1
29. Chaos Community Day London 2019 @gunnargrosch Latency injection
30. Chaos Community Day London 2019 @gunnargrosch Status code injection
31. Chaos Community Day London 2019 @gunnargrosch Exception injection
32. Chaos Community Day London 2019 @gunnargrosch Parameter control
33. Chaos Community Day London 2019 @gunnargrosch ”This is cool but now on to what we normally do.” Most serverless devs
34. Chaos Community Day London 2019 @gunnargrosch Serverless Chaos Demo app
35. Chaos Community Day London 2019 @gunnargrosch Serverless Chaos Demo app
36. Chaos Community Day London 2019 @gunnargrosch Failure injection • What if my function take 300 ms extra for each invocation? • What if my function returns an error code? • What if there is an exception in the code? • Hypothesis: My app can handle that failure is injected on a function level. • Let’s do it!
37. Chaos Community Day London 2019 @gunnargrosch “Serverless is a perfect fit for chaos engineering.” Gunnar Grosch
38. Chaos Community Day London 2019 @gunnargrosch Summary • Everything fails, all the time. • A resilient system maintains an acceptable level of service in the face of failure. • Serverless has challenges but is a perfect fit for chaos engineering. • Focus your experiments closer to the user. • Use graceful degradation. • You can do it!
39. Chaos Community Day London 2019 @gunnargrosch Inspiration
40. Chaos Community Day London 2019 @gunnargrosch Do you want more? • Follow @serverlesschaos on Twitter • Try the Serverless Chaos Demo app: https://demo.serverlesschaos.com • YouTube videos and repositories: https://grosch.se • Yan Cui’s article on chaos engineering for Lambda: https://hackernoon.com/how-can-we-apply-the-principles-of-chaos-engineering-to-aws- lambda-80f87e3237e2 • Adrian Hornsby’s article on failure injection: https://medium.com/@adhorn/failure-injection-gain-confidence-in-your-serverless- application-ce6c0060f586
41. @gunnargrosch grosch.se