I'm getting ready to expand an existing Cassandra cluster. I have repairs scheduled to run on a reoccurring basis. Do I need to disable repairs when adding a new node to a cluster, or can I bootstrap new nodes while repairs are running elsewhere in the cluster?
As per Datastax documentation,
Warning: DataStax recommends stopping repair operations during topology changes; the Repair Service does this automatically. Repairs running during a topology change are likely to error when it involves moving ranges.
So, it is clear that topology changes (adding/removing nodes) are not recommended when there is a repair process alive in your cluster