Now I have a cluster with three Data Centers and I need to expand this cluster. Can I expand one node in each Data Center at the same time? Additionally, I should set the parameter ‘consistent_rangemovement’ to ‘false’ to expand multiple nodes simultaneously. I’m not sure whether this operation will have negative effects on the cluster.
No, only one node can be added at a time. In ScyllaDB 6.0 with tablets, you can add nodes simultaenously.