Option 1 is only strictly safe if you run repair while the down replica is down (otherwise you validate quorum consistency guarantees)
Option 2 is probably easier to manage and wont require any special effort to avoid violating consistency. I'd probably go with option 2. On Thu, Feb 13, 2020 at 7:16 PM Sergio <lapostadiser...@gmail.com> wrote: > We have i3xlarge instances with data directory in the XFS filesystem that > is ephemeral and *hints*, *commit_log* and *saved_caches* in the EBS > volume. > Whenever AWS is going to retire the instance due to degraded hardware > performance is it better: > > Option 1) > - Nodetool drain > - Stop cassandra > - Restart the machine from aws-cli to be restored in a different VM > from the hypervisor > - Start Cassandra with -Dcassandra.replace_address > - We lose only the ephemeral but the commit_logs, hints, saved_cache > will be there > > > OR > > Option 2) > - Add a new node and wait for the NORMAL status > - Decommission the one that is going to be retired > - Run cleanup with cstar across the datacenters > > ? > > Thanks, > > Sergio >