Failures that are only visible from somewhere else
A meaningful share of production incidents are not global. A BGP route leak affects one continent. A CDN edge node serves stale or broken content in one metro. A geo-DNS rule sends an entire country to a decommissioned origin. A regional cloud zone degrades.
From a single probe location, every one of those looks like a perfectly healthy service — while a real segment of your users cannot load the page at all.
- BGP and routingPath changes that black-hole traffic from specific networks or continents.
- CDN edge failuresOne point of presence serving errors or stale objects while others are fine.
- Geo-DNS mistakesA misconfigured region record pointing part of the world at the wrong origin.
- Regional cloud incidentsProvider-level degradation in a single zone or region.
How quorum works
When a probe in one region reports a failure, that result alone never changes monitor state. It triggers immediate confirmation checks from other regions.
If the required number of regions agree the endpoint is failing, the monitor goes down and alerts dispatch. If they disagree — one region failing while others succeed — the event is classified as a regional anomaly. It appears in your history and per-region latency views, but it does not page anyone, because your service is in fact reachable for most users.
Reading per-region latency
Beyond up and down, the per-region view is a practical CDN audit. If your Singapore probe consistently sees three times the latency of your Frankfurt probe, your edge configuration is not doing what you think it is in Asia.
Comparing regional latency over time is also how you verify that a CDN change, a new origin location, or a routing tweak actually helped the users it was supposed to help.
Specifications
| Regions | US-East, London, Frankfurt, Singapore, Mumbai, Sydney, São Paulo |
|---|---|
| Confirmation | Quorum agreement across independent regions |
| Regional anomalies | Recorded without paging when quorum is not met |
| Per-region metrics | Latency and availability broken out by probe location |
| Region access | Number of available regions varies by plan |