# [[zPages]] zPages are a convention to expose service telemetry at well known urls (`/healthz`, `/varz`, `statusz`, `rpcz`) that originated at Google. Telemetry exposed in a standard way can be collected and aggregated by tools but can still be used to debug a service directly without the need for separate metric collection infrastructure. The `z` suffix is to reduce the potential for names clashing. `zPages` have been re-implemented by [OpenCensus](https://opencensus.io/) (now merged with OpenTracing as [OpenTelemetry](https://opentelemetry.io/)). Other open source tools like Prometheus (implemented by ex-Googlers) also implement this pattern. [[Kubernetes]] defines the (legacy) `healthz` and newer `livez` and `readyz` as part of the [API health endpoints](https://kubernetes.io/docs/reference/using-api/health-checks/#api-endpoints-for-health) ## References - [docker - Where does the convention of using /healthz for application health checks come from? - Stack Overflow](https://stackoverflow.com/questions/43380939/where-does-the-convention-of-using-healthz-for-application-health-checks-come-f) - [OpenTelemetry](https://opentelemetry.io/) - [Monitorama PDX 2016 - Kelsey Hightower - healthz: Stop reverse engineering applications and start monitoring from the inside on Vimeo](https://vimeo.com/173610242) --- - Links: - Created at: [[2021-04-07]]