Prometheus is an open-source monitoring solution with a dimensional data model and powerful query language for time series data.
Open source alternatives to Grafana Cloud
2 free, self-hostable tools you can use instead of Grafana Cloud, sorted by GitHub stars.
Alternatives to Grafana Cloud 2
InfluxDB
Replaces Grafana Cloud
Query high-frequency metrics and sensor data with an open source time series database built for real-time ingest and SQL analytics.