I've performed a rolling restart on a 3 nodes cluster. I've a replicas of 1, 4 shards per index and during the rolling restart, rebalance actions occurring makes my cluster always available and that's a good point. However, when the latest node of the cluster have finished to reboot, I see that there is no primary shards on it, only slave. Do you think this is a desirable effect ? Is there any advantage (regarding the balancing of the load) to force the placement of primary shards more homogeneously ?