Some questions on nodetool repair. 1. This tool repairs inconsistencies across replicas of the row. Since latest update always wins, I dont see inconsistencies other than ones resulting from the combination of deletes, tombstones, and crashed nodes. Technically, if data is never deleted from cassandra, then nodetool repair does not need to be run at all. Is this understanding correct? If wrong, can anyone provide other ways inconsistencies could occur?
2. Want to understand the performance of 'nodetool repair' in a Cassandra multi data center setup. As we add nodes to the cluster in various data centers, does the performance of nodetool repair on each node increase linearly, or is it quadratic ? The essence of this question is: If I have a keyspace with x number of replicas in each data center, do I have to deal with an upper limit on the number of data centers/nodes? Thanks Vish
