Engineering Large Systems When You're Not Google Or Facebook (test in prod)

lightning talk at Clever, 4/30/18

Transcript

1. Engineering Large Systems When You’re Not Google Or Facebook Some Advice By Charity Majors
3. I blame this guy: Testing in production has gotten a bad rap.
5. how they think we are how we really are
6. but *why*?
7. monitoring => observability known unknowns => unknown unknowns LAMP stack => distributed systems
8. “Complexity is increasing” - Science
9. Many catastrophic states exist at any given time. Your system is never entirely ‘up’
10. We are all distributed systems engineers now the unknowns outstrip the knowns why does this matter more and more?
11. Distributed systems are particularly hostile to being cloned or imitated (or monitored). (clients, concurrency, chaotic traffic patterns, edge cases …)
12. Distributed systems have an infinitely long list of almost-impossible failure scenarios that make staging environments particularly worthless. this is a black hole for engineering time
13. unit tests integration tests functional tests basic failover test before prod: … the basics. the simple stuff. known-unknowns
14. behavioral tests experiments load tests (!!) edge cases canaries rolling deploys multi-region test in prod: unknown-unknowns
15. test in staging? meh
16. unit tests integration tests functional tests “What happens when …” (you know the answer) “What happens when …” (you don’t) behavioral tests experiments load tests (!!) edge cases canaries rolling deploys multi-region test before prod: test in prod:
17. Only production is production. You can ONLY verify the deploy for any env by deploying to that env
18. 1. Every deploy is a *unique* exercise of your process+
 code+system 2. Deploy scripts are production code. If you’re using fabric or capistrano, this means you have fab/cap in production.
19. Staging is not production.
20. Why do people sink so much time into staging, when they can’t even tell if their own production environment is healthy or not?
21. That energy is better used elsewhere: Production. You can catch 80% of the bugs with 20% of the effort. And you should. @caitie’s PWL talk: https://youtu.be/-3tw2MYYT0Q
22. feature flags (launch darkly) high cardinality tooling (honeycomb) canary canary canaries, shadow systems (goturbine, linkerd) capture/replay for databases (apiary, percona) also build or use: plz dont build your own ffs
23. Failure is not rare Practice shipping and fixing lots of small problems And practice on your users!!
24. Failure: it’s “when”, not “if” (lots and lots and lots of “when’s”)
25. Does everyone … know what normal looks like? know how to deploy? know how to roll back? know how to canary? know how to debug in production? Practice!!~
29. • Charity Majors @mipsytipsy