> This makes total sense and is obvious in hindsight. But wouldn't such a > hypothetical "stale" row cache on be corrected by read repair (in other > words useless for write heavy workloads, not a problem for read heavy)?
It's not quite that simple. For example, suppose you write to the cluster at QUORUM consistency and then later read back at QUORUM. If you have a node which was part of the set of nodes that ACK:ed the write, but has now lost the data due to stale row cache, you're now having a node participating in the read set towards QUORUM for your read, even though it has forgotten the write it officially ACK:ed. Cassandra would now be violating the consistency guarantees it pretended to have. (That is ignoring any potential issues directly resulting from a node having an internally inconsistent state w.r.t. what's actually stored on the node.) -- / Peter Schuller
