RT @pfeodrippe
Hi, released a overhauled version of Recife, now using TLC :)

- Use Clojure and the REPL;
- Visualize the trace:
- Hillel's examples from his book:
- Also an example using @jepsen_io's Elle lib.

Made a small video about it at


A small change to the ethics policy (jepsen.io/ethics): for environmental reasons, Jepsen no longer performs analyses of proof-of-work or proof-of-space systems.

Jepsen 0.2.4 is now available. New SSH backend options, performance improvements, and a local filesystem cache to speed up DB setup. Happy testing! github.com/jepsen-io/jepsen/re


"We might get outputs that are arbitrarily wrong, up to and including breaking program invariants"

"The outputs might never converge to correctness"

Giving a short talk on Jepsen at LADIS this afternoon! Our session starts at 14:45 US Eastern. ladisworkshop.org/2021/

Live stream:

New release! Maelstrom 0.2.0 is a workbench for learning distributed systems by writing your own, in any language. Comes with a six-chapter tutorial in writing your own toy echo, gossip, CRDT, Datomic, and Raft systems. Powered by Jepsen and Elle! github.com/jepsen-io/maelstrom

New Jepsen release: 0.2.3. Super small, just a few bugfixes and performance improvements. Enjoy! github.com/jepsen-io/jepsen/re

Howdy guys, gals, and non-binary pals! Jepsen 0.2.2 is now available, with a slew of minor bugfixes, performance improvements, and new utility functions. Look out for a change to multi-fault nemesis scheduling: github.com/jepsen-io/jepsen/re

RT @asatarin
"Cobra: Making Transactional Key-Value Stores Verifiably Serializable"

Given black box trace of KV transactions determine if observed behaviors are serializable at scale (10K transactions)


New report: we worked with @ScyllaDB to identify and fix cases of LWT split-brain in healthy clusters due to improper hashing and membership changes, as well as documentation improvements. Notably, Scylla no longer claims non-LWT isolation! jepsen.io/analyses/scylla-4.2-

RT @yow_conf
Can you believe it?! We're adding ONE more speaker to and it's @aphyr!

We trust databases to store our data, but should we? Learn the basics of distributed systems testing & advice for testing your own systems in his keynote - Jepsen 13.

RT @adriancolyer
"Elle: inferring isolation anomalies from experimental observations", Kingsbury & Alvaro, VLDB'20. blog.acolyer.org/2020/11/23/el

Be afraid databases, be very afraid: Jepsen just got a whole lot more powerful...

Jepsen's AWS Marketplace product (launches a whole Jepsen cluster in a few clicks) has been updated for Debian Buster, and now includes additional dependencies you'll want for running tests based on Elle. Happy testing!


Put a bunch of work into the Jepsen docker-compose setup, and I'm pleased to report it now gives you a full Debian Buster cluster with keys and dependencies out of the box--should be good for running the latest tests. Hopefully this helps!


Do you use Cassandra or another CQL-compatible database? I'd like to hear your perspective on adding things to a CQL set: docs.google.com/forms/d/e/1FAI

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