Beyond-5s

FoundationDB keeps conflict history for five seconds. Resolver v1 keeps it under a memory budget instead, in a temporal B+ tree whose nodes and key bytes share one pool. Under 6 GiB it retains 2.2× the history of the original skip list, at 2.7× the resolution time; this post explains the design and the measurement.

FoundationDB rejects any transaction older than five seconds. Beyond 5s replaces that fixed window with budgets, component by component: the resolver’s conflict history, the storage server’s version retention, and the protocol that coordinates them. This page lists the milestones in order.