Silences and maintenance windows

A silence stops an alert being delivered. It does not stop it being evaluated or recorded — the state machine runs regardless, and the history shows what fired while you were not being told, which is what a post-mortem needs.

Open one from the cluster header (Silence…) or the command palette: one hour, four hours, indefinitely, or off.

What a silence covers

Silences are scoped to a cluster, and optionally to a rule and a target pattern. A silence with no rule covers everything in that cluster.

Expired silences are cleaned up on the next poll, so a one-hour window genuinely ends after an hour without anything to switch off.

Quorum loss ignores silences

A lost quorum is delivered even while a silence is open.

Without quorum the cluster cannot schedule anything, and a blanket maintenance silence — which is exactly the sort of thing that is open during risky work — must not be able to hide the cluster falling over. That is precisely when you most need to know.

This applies to ClusterQuorumLost specifically. Other rules, including No leader, respect silences normally.

Acknowledging instead

Acknowledging an alert mutes its delivery but leaves it visible in the inbox. Use it when you know about something and are working on it — a silence is for planned work, an ack is for "yes, I've seen it".