We have two DCs with 20+ Cassandra nodes in each, data has RF=3
From time to time we read to quick after a write, so all 3 nodes in the cluster does no have the data just yet, and this triggers a READ REPAIR
Somehow Cassandra is configured to do a READ REPAIR two all DCs, so DC1 and DC2 in my case.
Here something goes wrong occasionally and the READ REPAIR times out
1. How can I figure why that READ REPAIR timed out, which node did not respond, or .. was there some other reason
2. Is it possible to say do READ REPAIR only DC1, and then in the background Cassandra can synch up with DC2