Silences
A silence is a temporary mute. Use it for known maintenance windows, vendor outages, or noisy alerts you're already investigating.
While a silence is active, any alert whose labels match it does not produce notifications. The alert still fires internally and shows up on the Active tab, but no email/Slack/page goes out.
Three states
The Silences tab has three sub-tabs:
- Active — currently suppressing alerts.
- Pending — scheduled to start in the future.
- Expired — finished. Kept for audit.
Form fields
Match labels
Label matchers using the same operators as rules and routing: =, !=, =~, !~.
A silence with service = payments matches every alert tagged with service=payments. A silence with both service = payments and severity = warning matches only payments alerts at warning severity.
Empty matchers match every alert. That's almost never what you want — it's a global mute.
Start
When the silence becomes active. Default: now.
Duration
How long the silence lasts. Examples: 1h, 30m, 8h, 7d.
You can also set an explicit End time instead of a duration; the form has a toggle.
Comment
Why this silence exists. The on-call coming off shift will thank you.
Examples:
- "Database upgrade window — INC-2143"
- "Vendor API maintenance, ack'd in their status page"
- "Investigating root cause, see Slack #incidents"
Common patterns
Maintenance window
match: service = payments start: 2026-05-04 22:00 UTC duration: 4h comment: Q2 deploy window — INC-2143
Suppress one noisy alert
match: alert_name = "Old certificate warning" duration: 7d comment: Cert renewal in flight, see Jira OPS-441
Whole-cluster maintenance
match: cluster = staging duration: 2h comment: Staging upgrade — see #infra
Expiring early
Active silences have an "Expire now" action. Use it when maintenance ends ahead of schedule. The silence moves to Expired and notifications resume immediately.
Tips
- Always include a comment. Future you will not remember why.
- Match by
serviceorclusterrather than by alert name when possible. New alerts you didn't know about will inherit the silence. - Don't silence an alert because it's wrong. Fix the rule. Silences are for known noise, not buggy thresholds.