Q: Cassandra move data on another cluster i have a 3 node Cassandra cluster (3.11.0) and i want to move this cluster onto another location.
i have a 3 vm in my old cluster (Tashkent cluster)
192.168.1.11 -1 node
192.168.1.12 -2 node
192.168.1.13 -3 node

and i have new (empty) cluster
172.17.5.10 -1 node
172.17.5.11 -2 node
172.17.5.12 -3 node

and i want to move all the data from old cluster, to new and my steps is (old cluster have RF=3 for all keyspaces and have a NetworkTopologystrategy BTW)
1) add old nodes as seeds to new cluster
2) bootstrap new nodes
3) nodetool cleanup on old nodes
4) then run nodetool decommision on old nodes, one by one
5) nodetool removenode <oldnodeip>

so my plan is correct? should i do nodetool repair after ster 3?
thanks

A: Instead of doing bootstrap/decomission, it's could be much faster to do following:

*

*Add all new nodes as a new data center

*Adjust replication factor to use 2nd data center

*Run nodetool rebuild from every node of the new DC

*Switch applications to new DC

*Decomission the DC

Steps 1-3 are described in the following documentation, step 5 is described here.
Another possibility is perform the replacing nodes one by one.
Main advantage in the both cases is that you're minimizing the data movements between the nodes.  Otherwise you'll move the data when adding nodes, and then move again when doing decomission or removenode

A: Nodetool cleanup should be replaced by nodetool repair. Cleanup removes extra data from nodes and running it in older nodes will not be beneficial, while repair streams any missing data. Also, nodetool removenode will not be required after decommission.Both perform the same function but in different ways.
