Can we know whether server is reachable or not in grafana dashboard

[mattabrams]

Have you tried using the built-in {up} metric?

Http(s) status monitoring

Have you tried using Prometheus? Prometheus has a built-metric called up{} where every time it scrapes an endpoint, it returns 1 for up and 0 for down. You should also check out loki for status codes: https://play.grafana.org/d/T512JVH7z/loki-nginx-service-mesh-json-version?orgId=1