How Testing a Convergence Theory Led to a Replication Bug Fix in Apache CouchDB
Two CouchDB databases got the same replications in the same order. One ended with a document deleted, the other with it live, and the only difference was a validation function that accepts everything. This is the full path from a theory of convergence, to a model of CouchDB’s replication, to a prediction committed before any test, to the one scenario the model got wrong, to the bug behind it and the fix that merged into CouchDB.