With a Java-Datalogger we can write events and alerts to different data sinks. For example we can use ElasticSearch and Kibana to discover alerts collected by WinCC OA. Elasticsearch provides full text search, analytics, dashboards. And now it also supports graphs!
“Graph introduces a new way to discover, and explore, the relationships that live in your data. Adding relevance to the process of exploration, a unique combination of graph and search means you can do things like detect fraud, recommend content, and more.” https://www.elastic.co/de/products/graph
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.
Cassandra Performance Stats