We're considering working on a new feature that will allow "mounting" part of the namespace of one ZK cluster into another ZK cluster. The goal is essentially to be able to partition a ZK namespace while preserving current ZK semantics as much as possible.
More details are here: http://wiki.apache.org/hadoop/ZooKeeper/MountRemoteZookeeper
It would be great to get your feedback and especially please let us know if you think your application can benefit from this feature.
Alex Shraer and Eddie Bortnikov
Benjamin Reed 2011-06-09, 23:05