Checks
A check is an HTTP GET that Lumin sends from its own servers to a URL you give it. The agent is not involved: checks work with nothing installed, so they are usually the first signal you set up. The dashboard home opens on them.
What a probe does
Section titled “What a probe does”Every probe is a GET with User-Agent: Lumin-Checks/1.0. It follows up to 5 redirects and reads at most 4 KB of the response body. The result is one of four statuses:
| Status | Meaning |
|---|---|
| up | The URL answered with a status below 400, inside the timeout. |
| degraded | The URL answered, but slower than your “Degraded above” threshold. |
| down | A status of 400 or higher, a timeout, or a connection failure. |
| paused | The check is disabled. Lumin keeps the config and stops probing. |
Configuration
Section titled “Configuration”| Field | Values |
|---|---|
| Name | Defaults to the URL host. |
| URL | http or https. |
| Interval | 30 s, 1 min, 5 min, or 15 min. Default 1 min. |
| Timeout | 1–30 s. Default 10 s. |
| Degraded above | Optional, in milliseconds, up to 300 s. |
A project holds up to 50 checks. A check belongs to the environment that is selected when you create it, so the environment picker filters the check list like every other board.
What the dashboard shows
Section titled “What the dashboard shows”The home page summarises the selected time window: KPI tiles for Uptime, Avg response (with p95 and p99), Checks, and Incidents, plus one row per check with its uptime percentage and a 60-bucket status timeline. Each bucket shows the worst status inside it, so a single failed probe stays visible in a wide window.
Public URLs only
Section titled “Public URLs only”The prober refuses targets that resolve to loopback, private, link-local, or carrier-grade-NAT addresses, and it re-checks every redirect hop. Point checks at your public edge — the domain your users hit. Container-internal health is the agent’s job, not a check’s.
What a check does not do yet
Section titled “What a check does not do yet”- No TCP checks, heartbeat checks, keyword assertions, or SSL-expiry checks. Only HTTP GET exists today.
- No public status page.
- No alert fires from a check. Alert rules watch metrics and log patterns. A failed check shows on the dashboard, but Lumin does not post to Slack about it yet.
Retention
Section titled “Retention”Probe results follow the project’s retention window like any other signal — see Retention. Deleting a check stops the probes; its history stays until retention removes it.