No, that's really different. - nodequery source (and ecosystem) is closed - "periodically store various system data" "minute" VS "low-latency" - email notifi

No, that's really different. - nodequery source (and ecosystem) is closed - "periodically store various system data" "minute" VS "low-latency" - email notifications only - no query language, but a JSON API → overhead Riemann looks more free (libre as well as liberty of usage, you can just monitor anything), more in-depth (does more with lower latency objectives) and better designed (DSL for rules, protobuff over tcp and udp instead of json over http over tcp).