WAL only helps so much, since you also need seeks for reads. Cassandra has a WAL + log-structured storage + no read-before-update design, so it basically elimi

WAL only helps so much, since you also need seeks for reads. Cassandra has a WAL + log-structured storage + no read-before-update design, so it basically eliminates seeks on writes entirely, and EBS is still ass for workloads that don't fit in cache. Which, if you're bothering to use C*, is almost all of them.