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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.
https://querybuilder.js.org look this up to get an idea ;)
Sentry has alert rules and it is open source. This topic is generally called a "rules engine". Most likely no package is going to magically meet your requirements. Only you can balance the tradeoffs on flexibility, performance, security, and user experience. On one hand you can make a rules engine that "just" exec's some code like for Auth0. On the other hand, you're building your own custom graphical programming language.
NOTE:
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Hence, a higher number means a more popular project.