Did a first test with Cassandra as NoSQL database store for WinCC OA event logging.
Cassandra was easy to install, pretty good write performance and very good read performance. Compared to e.g. OpenTSDB the CPU load on client and server are higher.
Test-Setup: 5000 values/second, 24h, 392 Mil.Records, One Hyper-V server on an i7 3.1Ghz with 4 Cassandra nodes, each node with two cores, disks on a shared storage space device with 4 disks and raid 0 (i know that’s not a real life scenario for a NoSQL cluster). WinCC OA and the Java-Historian-DB-Logger running on another Hyper-V server on an old i5 CPU 750 @ 2.67 Ghz.