I have a scylla cluster running on AWS i3en.xlarge instances which has 16 nodes.
Is there an easy way for me to switch the cluster to i3en.2xlarge or i3en.4xlarge other than replacing existing node one by one (e.g. add a new node and remove a node)?
If I add one i3en.2xlarge instance, will the cluster auto balances the data so that on the i3en.2xlarge it uses roughly twice the disk space as i3en.xlarge?
You can add a logical DC of the new nodes, run repair and then get rid of the original DC
Add a new DC with the desired instance type (see the procedure @TzachLivyatan posted in his comment)
Wait for streaming to the new DC to complete
Run a full cluster repair -> wait for it to complete
Decommission the "original" DC: https://docs.scylladb.com/operating-scylla/procedures/cluster-management/decommissioning_data_center/
