This project has been used for demonstration purposes during a Java meetup at Thessaloniki (https://www.meetup.com/Thessaloniki-Java-Meetup-Group/events/240809028/)
The raspberry pi sends some data from the temperature/humidity sensor (https://www.adafruit.com/product/393) using Python.
The data would then be ingested to CrateDB through the Spring application. Finally we visualise the data with the help of the Grafana project (https://grafana.com/).
Under a real environment there would be a load balancer in front of the applications. Each application would connect directly with a CrateDB.
The system has been tested with CrateDB version 1.1.5.
The Docker commands that have been used for the presentation can be found under the presentation folder along with
the presentation material.
Up to version 0.57.0 with the Java client it was possible to use JPA. After that version this is not possible anymore (https://github.com/crate/crate-sample-apps/blob/master/java/documentation.md). That is why I used simple JDBC at my sample application.
I have been based on this sample from AdaFruit (https://github.com/adafruit/Adafruit_Python_DHT/blob/master/examples/AdafruitDHT.py) in order to send the data rom the sensors to the spring boot application. The code can be found under the crate/client folder.