John Daily covers Riak’s mechanisms for bringing data in sync across the nodes:
Riak’s overarching design goal is simple: be maximally available. […]
In order to make sure your data can survive server failures, Riak
retains multiple copies (replicas) and allows lock-free,
uncoordinated updates. […]
This then open ups the possibility that data will be out of sync across a
cluster. Riak manages this issue in three distinct stages: entropy
detection, correction, and conflict resolution.
You’ll read pitches from products promising both maximal availability and no out-of-date data. Those are just that promises.
Original title and link: Riak: Entropy detection, correction, and conflict resolution