I ran a cbbackup of a single bucket, 4 node, 2.2.0 community edition (build-837) cluster that was fairly imbalanced (718k, 565k, 383k, 383k items in each node), created a new 3 node cluster (same build), and ran cbrestore. The new cluster also came up imbalanced (1035k, 515k, 516k items in each node). In order to distribute the keys evenly, we added a node and ran rebalance, but a significant imbalance remained akin to the distribution in the old cluster. We removed the new node and rebalanced, and the item distribution went back to what it was. We actually did this twice just to see if it would make a difference. All rebalances completed successfully. Note that the replica distributions are similarly skewed where one node has about twice the number of items as the others.
Any ideas about how to correct the skew of data across servers? Any ideas of why it would skew in the first place? Is there risk that if one node goes down, there will be a loss of data?