Jepsen’s distributed systems training introduces engineers and operators to the fundamentals of nodes and networks, consistency and availability, techniques for replicating state, a slew of design patterns, and production concerns. By popular request, we’re offering a special session of this class that anyone can register for. Join us on Zoom, December 16th through 19th, 2024. Tickets are on sale now.
About Jepsen
Jepsen is an effort to improve the safety of distributed databases, queues, consensus systems, etc. We maintain an open source software library for systems testing, as well as blog posts and conference talks exploring particular systems’ failure modes. In each analysis we explore whether the system lives up to its documentation’s claims, file new bugs, and suggest recommendations for operators.
Jepsen pushes vendors to make accurate claims and test their software rigorously, helps users choose databases and queues that fit their needs, and teaches engineers how to evaluate distributed systems correctness for themselves.
In addition to public analyses, Jepsen offers technical talks, training classes, and a variety of consulting services.
Other Resources
News
Recent research, analyses, and announcements.
Jepsen 0.3.6
2024-10-17
Jepsen 0.3.6 is now available on GitHub and Clojars. This is a sizeable release. It includes a significant correctness bugfix for a rare bug that could make operations in the history print with the wrong data. It also adds a new namespace for composing databases, nemeses, and generators when working with systems where each node has a different role. Kafka-style tests gain new powers and are significantly faster. And we have the usual slew of small bugfixes, dependency bumps, and quality-of-life improvements. Happy testing!
The full release notes are available on GitHub.
Jepsen 16 - Systems Distributed 2024
2024-08-28
Kyle Kingsbury spoke at Systems Distributed 2024 on RavenDB, MariaDB/MySQL, and Datomic.
jetcd 0.8.2
2024-08-07
Jepsen traced lost update, circular information flow, and aborted reads in etcd tests to an improper retry mechanism in jetcd 0.8.2, which allowed transactions to be submitted multiple times, and for committed transactions to appear as if they had actually failed.
Goto Chicago 2024
2024-07-22
Kyle Kingsbury will speak on performance techniques in Jepsen at GOTO Chicago, October 21 & 22, 2024. The talk will touch on a mix of high-level and low-level performance optimizations to make checking large histories tractable, including parallelism, pure functions, immutable data structures, and deforestation; bitsets, avoiding sharing between threads, packing structures into mutable arrays, dynamic compilation of primitive boxes, and macro iteration magic.
Early bird tickets are on sale now.