Pings only see the public envelope
A ping confirms a single endpoint accepted a single request at a single moment. It does not see:- The error rate served to actual customers in the last five minutes.
- The 95th percentile latency under real load.
- The depth of an internal queue draining slower than its inflow.
- A degraded backend that has been masked by retries upstream.
Metrics see the actual signal
Observer’s primary data source is your own metrics: Prometheus queries, HTTP probes that include body checks, TCP connection times, DNS resolution times, TLS certificate expiry. The status the public page shows is computed from the same numbers your on-call team already trusts on the internal Grafana dashboard. The result: when customers see red, the on-call’s dashboard shows the same red, with the same threshold semantics.Pings still have a place
For systems that do not emit metrics (third-party APIs, public DNS, certificates issued by external CAs), the agent runs probes directly. Observer also supports HTTP, TCP, DNS, ICMP, TLS certificate, gRPC, WebSocket, database, OTLP, CloudWatch, Loki, Elasticsearch, host metrics and custom probes. These produce a metric in the same shape as a Prometheus query: a numeric value with a timestamp, evaluated against thresholds.Use the right source per signal
- Internal API health: Prometheus query against your own metrics.
- Third-party API reachability: HTTP probe.
- Certificate expiry: TLS-cert probe.
- DNS health: DNS probe.

