Checks and their status
A Monitor asks its target up to four questions. Each question is a Check, with its own status. Every Check is included on every Plan.
- Uptime: does it answer?
- Performance: does it answer slower than you want?
- Certificate: is its certificate trusted, and when does it expire?
- Domain: when does its domain registration expire?
Which Checks a Monitor carries
Section titled “Which Checks a Monitor carries”| Monitor | Checks |
|---|---|
| Website and API | Uptime, Performance, Certificate, Domain |
| TCP | Uptime, Performance |
| Ping | Uptime, Performance |
| Heartbeat | Uptime |
A Monitor has each of its Checks from the moment it is created. A Certificate Check needs an https address, and a Domain Check needs a domain name whose registry we can read. Where a Check does not apply, the Monitor’s Checks card says why.
You can turn the Performance, Certificate and Domain Checks off and on with their switches. The Uptime Check is always on, because it decides whether the Monitor is up. To stop it, pause the Monitor.
The four statuses
Section titled “The four statuses”Each Check that is on has one of these statuses. The dashboard shows it beside the Check’s name.
- pending: there is no result yet. A new Check is pending until its first result, and so is a Check on a Monitor you resumed, or a Check whose Incident you resolved by hand.
- ok: the Check found nothing wrong.
- warning: worth your attention, but the target is working. A certificate or a domain expires soon, answers are slower than your threshold, or the target answers over IPv4 and not over IPv6. A warning never opens an Incident, never shows on your Status page and never spends a credit. Warnings wait for a digest, so they do not arrive the moment they start: see When warnings arrive.
- failed: the Check found a failure, and it has an open Incident.
A Monitor’s status
Section titled “A Monitor’s status”A Monitor’s status is the worst status among its Checks that are on, from worst to best: failed, warning, pending, ok.
Only the Uptime Check can make a Monitor pending. Once it has a result, another Check that is still waiting for its first one does not hold the whole Monitor back. A Monitor with every Check off reads no Check enabled. A paused Monitor reads paused.
What counts as down
Section titled “What counts as down”Only the Uptime Check says a Monitor is down. Only its Incidents count against your uptime percentage, and only it shows on your Status page. An expired certificate or domain opens an Incident on its own Check: you are alerted, and your uptime does not change.
When the server stops answering
Section titled “When the server stops answering”When your server stops answering, its other Checks can fail with it. You hear one message: the uptime alert, which says what went wrong. A Certificate or Domain failure found while uptime is failing waits behind it.
Once uptime is back, we look at that Check again. If it now passes, you never hear about it. If it still fails, you hear about it after the message that says your Monitor is up again.