This could be an interesting alternative to using OpenTSDB for time series data.
Useful Links
https://blog.timescale.com/blog/create-a-data-pipeline-with-timescaledb-and-kafka/
...
https://docs.confluent.io/3.1.1/connect/connect-jdbc/docs/sink_connector.html
https://www.confluent.io/blog/kafka-connect-deep-dive-converters-serialization-explained