Alex, 12 years ago I filed CASSANDRA-8494 hoping someone much smarter than me would take on the Herculean effort of completely reworking how we manage our data. This CEP addresses my wish for incremental bootstrap and also incorporates tablets, which have been on my radar for a long time. This work will address some of Cassandra's biggest pain points today for operators.
Thank you so much for this. I cannot overstate my enthusiasm for this CEP!! Jon On Tue, Feb 24, 2026 at 12:17 AM Alex Petrov <[email protected]> wrote: > Hi everyone, > > We'd like to propose CEP-60: Flexible Placements [1] for adoption by the > community. Building on CEP-21's Transactional Cluster Metadata [2], CEP-60 > enables incremental, resumable operations, improved cluster density, and > flexibility of data placements / ownership. > > CEP-60 benefits all users by further improving reliability of ownership > operations. With flexible placements, clusters maintain near-optimal load > balance at any size without explicit rebalancing phases. Ownership changes > are broken into smaller sub-range steps that benefit from zero-copy > streaming. > > CEP-60 is designed for incremental delivery: range-aware compaction, > routing key abstractions, and metrics collection are useful on their own > and will ship independently of the flexible placements feature. Existing > token-based and vnode clusters will continue to work (while benefitting > from incremental ops), and flexible placements can be enabled (and later > disabled, if ever needed) on a per-keyspace basis. > > The CEP is linked here: > https://cwiki.apache.org/confluence/display/CASSANDRA/CEP-60:+Flexible+Placements > > Looking forward to the discussion of this CEP here on the dev list. > > Thanks! > > [1] > https://cwiki.apache.org/confluence/display/CASSANDRA/CEP-60:+Flexible+Placements > [2] > https://cwiki.apache.org/confluence/display/CASSANDRA/CEP-21%3A+Transactional+Cluster+Metadata >
