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InfluxDB
Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
Java + SpringBoot is very simple. Use https://start.spring.io (web dependency) to make a simple server that does the RESTful mapping (PostMapping, GetMapping, PutMapping, DeleteMapping) in a RestController. Other than a database, there is not much more to learn on the server-side. It is really just more of the same RESTful mapping and storing and retrieving that information from the database.
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