OpenTelemetry and Uptrace are used to monitor CPU/RAM/disk metrics.

OpenTeleletry Collector is a free and open source data gathering pipeline that lets you monitor CPU, RAM, disc, network, and other metrics.

Collector does not have built-in storage or analysis capabilities, but you can export data to Uptrace and ClickHouse, which may be used in place of Grafana and Prometheus.

When analyzing millions of timeseries, ClickHouse outperforms Prometheus in terms of on-disk data size and query speed.