Cassandra

Apache Cassandra is a distributed NoSQL store that replicates data across many nodes using an append-only write path, so every machine in the cluster can accept reads and writes. Consistency is tunable per query, which lets you trade strict agreement for latency on read-heavy paths, and the cluster keeps serving traffic when nodes or racks fail.

It is a common fit for time-ordered event, message, and sensor data at high write rates, as well as session state and user profiles spread across regions.

Deploying it through The service can the ring on your own hardware, where you set replication and compaction yourself and pay nothing per node.