Quorum read consistency in Cassandra
With having QUORUM for both read &amp; write requrests you achieve strong consistency per following equation R + W &gt; N, where R - read replica count, W - write replica count, and N - replication factor.

If you write with QUORUM, then 2 nodes will get fresh data, and when you read with QUORUM, then one node may have the old data, and one will have fresh data - Cassandra will detect discrepancy &amp; use the newest version.