Silences

While a silence is active, the events it matches are still recorded in the feed but sent nowhere. The Silences page is where you create one, end one early, and see which ones apply. How a silence interacts with routes and open notifications is covered in Noise control.

One active silence on the topic infra.disk.*, with its comment, when it ends and who created it.

One active silence on the topic infra.disk.*, with its comment, when it ends and who created it.

Creating a silence

1. Press New silence.

2. Under Which events, say what to silence. The fields are the same as a route’s conditions:

   • Topic: an exact topic, or a pattern in which * matches any run of characters, as in orders.*.
   • Minimum severity and Source.
   • Add label condition: a label key that equals a value, matches a regular expression, or is present.
   • Expression: an optional test over the event. See Expressions and templates.

   An event must meet all the conditions you fill in. A line under the fields repeats them in words, for example “Silences: topic infra.disk.*”. At least one condition is required: a silence cannot cover every event.

3. Under For how long, choose 30 min, 1 h, 4 h or 24 h, or Until a date and time and fill in Ends at. The form starts on 1 h. A date and time is in your browser’s time zone and must be in the future.

4. Optionally write a Comment saying why, up to 500 characters. It is shown in the list and as the reason on notifications the silence holds back.

5. Press Create silence.

A silence created here starts at once. It can last at most a year.

Silencing from a notification

The Silence button on a notification opens this form already filled in with the topic and every label of the event that opened the notification. Loosen it before creating, for example by removing a label that is unique to one event. See Notifications.

The lists

The three buttons above the table switch between silences by when they apply. Each carries a count.

List	Holds	Starts sorted by	Action
Active	Silences that apply now.	The one ending soonest first.	End now
Upcoming	Silences that start later.	The one starting soonest first.	Delete
Ended	Silences that are over.	The one that ended last first.	Delete

The form on this page always starts a silence now. An upcoming one exists only when it was created through the admin API with a start time.

The columns:

Column	What it shows
Events silenced	The conditions in words, with the comment underneath.
Ends, Starts or Ended	For an active silence, “ends in 1 h, at 22:51”. For an upcoming one, when it starts and for how long. For an ended one, how long ago.
Created by	The email address of the person, “API token”, or a Slack user name followed by “(Slack)” for a silence made with the Slack app button.
Created	When it was created.
Actions	End now or Delete.

The search box (“Search conditions, comment or author”) filters the list in view. The lists re-sort themselves every 15 seconds, so a silence that ends moves to Ended without a reload. The page holds up to 500 silences.

Ending and deleting

• End now sets an active silence’s end to this moment. It moves to Ended, and matching events are sent again from then on. Events that arrived while it was active stay unsent.
• Delete removes an upcoming or ended silence from the list. Both buttons ask for confirmation first.

When there are no silences at all, the page says “No silences, so every event that matches a route is sent.”

Seeing what a silence held back

A notification that a silence suppressed is listed under the Not sent view of Notifications, with “silenced:” and the silence’s comment as the reason. In the Feed, filter by the outcome Not sent. The route tester on Routes also takes active silences into account and names the one that applies.