There is a feature request to allow to choose whether and where to start a rebalancer, see #278. It allows to choose certain instances to run the rebalancer.

However, it would be convenient to choose a replicaset to run the rebalancer assuming that it works on a master (writable node) and paused on a replica (read-only node).

It requires support of tracking ro/rw status of a current instance, which is planned to be implented in #429.

Follows up #278
Follows up #429