Staying quiet when you should

Snoozing, maintenance windows, flapping, and what LastSeen does when the trouble is on its side, not yours.

An alert you didn't need is worse than useless: it teaches you to ignore the next one. These are the ways LastSeen holds back.

In every case, status keeps telling the truth: a snoozed monitor that goes down shows as down. Only the alerts wait.

Snooze #

On a monitor's page, Snooze alerts holds its alerts for 1 hour, 4 hours, a day or a week (members and up can snooze). The Snooze 1h link in an alert does the same. When the snooze ends:

• if it went down during the snooze and is still down, you get one down alert then;
• if it went down and came back during the snooze, you hear nothing;
• if it was already down when you snoozed (so you knew), you hear nothing more until it recovers.

End snooze on the monitor's page lifts it early.

Maintenance windows #

For planned work, add a window on Maintenance: once, or every week on chosen days, at a time in your timezone. A window covers every monitor, or chosen monitors and tags. While it's open, their alerts wait; when it closes, anything still wrong is alerted on then. The monitor list and pages say when a window is holding alerts, and each monitor's history notes the window starting and ending. An organization can have up to 20 windows.

Flapping #

A monitor that keeps going down and coming back (a device on the edge of Wi-Fi range, say) would send an alert every few minutes. Instead, the 3rd change between up and down within 15m makes it unstable: you get one alert saying so, and nothing more for it until it has stayed steady for 15m. Then you hear whether it settled up or down.

Reminders and quiet hours #

Notification profiles can wait before alerting (so a blip that fixes itself never reaches you), remind you while something stays down, and hold alerts during quiet hours, with an exception for down alerts if you want them anyway.

When LastSeen itself has trouble #

If LastSeen's own receiving end breaks, every monitor would look silent at once, and you'd get a flood of false down alerts. So LastSeen watches for that:

• Canaries outside LastSeen ping it constantly. If every canary and every monitor goes quiet together for 45s, the silence is ours, not yours.
• While that's so, monitors can go late (it's shown honestly) but not down, so no alerts are sent.
• When pings arrive again, every monitor gets a fresh start: its deadlines count from then, so a device isn't blamed for the minutes we couldn't hear it.

Website checks do the same with sites of our own: if those fail from a region, that region's results don't count until they pass again.

Devices behind an agent work the same way: if the agent goes quiet, you get one alert about the agent, and the monitors behind it wait instead of alerting one by one.