jepsen.generator

This library provides the compositional generator system at the heart of Jepsen.

Generators produce a series of operations Jepsen would like to perform against a system, like "Set key x to 3". They also react to operations as they happen. For example, if a write fails, the generator could decide to retry it.

In addition to the generators themselves, this library provides:

• jepsen.random: Pluggable random values
• jepsen.generator.test: Helpers for testing generators
• jepsen.generator.context: A high-performance, pure data structure which keeps track of the state used by generators
• jepsen.generator.translation-table: Maps worker threads to integers

Example

(gen/phases (->> (gen/mix [(repeat {:f :read})
                           (map (fn [x] {:f :write, :value x}) (range))])
                 (gen/stagger 1/10)
                 (gen/nemesis (->> (cycle [{:f :break}
                                           {:f :repair}])
                                   (gen/stagger 5)))
                 (gen/time-limit 30))
            (gen/log "Recovering")
            (gen/nemesis {:f :repair})
            (gen/sleep 10)
            (gen/log "Final read")
            (gen/clients (gen/each-thread (gen/until-ok {:f :read}))))

License

Copyright © Jepsen, LLC

This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which is available at https://www.eclipse.org/legal/epl-2.0.

This Source Code may also be made available under the following Secondary Licenses when the conditions for such availability set forth in the Eclipse Public License, v. 2.0 are satisfied: GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version, with the GNU Classpath Exception which is available at https://www.gnu.org/software/classpath/license.html.