I was reading through configuration tips for cassandra and decided to use row-cache in order to optimize the read performance on my cluster.

I have a cluster of 10 nodes, each of them opeartion with 3 GB off-heap using cassandra 2.4.1. I am doing local quorum reads, which means that I will hit 3 nodes out of 5 because I split my 10 nodes into two data-centres.

I was under the impression that since each node gets a certain range of reads my total amount of off-heap would be 10 * 3 GB = 30 GB. However is this still correct with quorum reads? How does cassandra handle row-cache hits in combination with quorum reads?

Thanks!
-- artur