Jepsen @ Tendermint

A short presentation explaining what Jepsen is and how it roughly works. It also highlights the specific test cases in Tendermint.

1. github.com/melekes Jepsen
2. github.com/aphyr A framework for distributed systems veri fi cation, with fault injection
3. • Linearizability checkers (Knossos, Elle) • Fault injection (network partitions, crashes, clock skews) • Visualization • Flexible API • it’s written in Clojure 😒
4. https://jepsen.io/consistency Linearizability
5. Transaction Isolation Levels in Posgresql https://www.postgresql.org/docs/9.5/transaction-iso.html
6. “each operation appears to take e ff ect atomically at some point between its invocation and completion.” https://aphyr.com/posts/313-strong-consistency-models
7. Jepsen & Tendermint https://jepsen.io/analyses/tendermint-0-10-2 https://github.com/tendermint/jepsen
8. Test scenarios • Network partitions (different combinations) • Clock skews • Crashes • Changing validators • Truncating logs 

9. "Tendermint appears to satisfy its safety guarantees” Sept. 2017.
10. What about now?
11. Everything still looks good👍
12. “Talk is cheap. Show me the code.” Linus Torvalds
16. Nemesis can be used to inject faults
17. So… how does Jepsen work?
18. https://www.youtube.com/watch?v=OPJ_IcdSqig Black-box Isolation Checking with Elle (Kyle Kingsbury, Jepsen.io)
19. https://www.youtube.com/watch?v=OPJ_IcdSqig Black-box Isolation Checking with Elle (Kyle Kingsbury, Jepsen.io)
20. https://www.youtube.com/watch?v=OPJ_IcdSqig Black-box Isolation Checking with Elle (Kyle Kingsbury, Jepsen.io)
21. https://github.com/tendermint/jepsen
22. github.com/melekes Thank you!