alerts/absent

This check will warn you about alerting rules that are using absent() calls without having for option set to at least 2x scrape interval. Using absent() without for can cause false positive alerts when Prometheus is restarted and the rule is evaluated before the metrics tested using absent() are scraped. Adding a for option with at least 2x scrape interval is usually enough to prevent this from happening.

Configuration

This check doesn’t have any configuration options.

How to enable it

This check is enabled by default for all configured Prometheus servers.

Example:

prometheus "prod" {
  uri     = "https://prometheus-prod.example.com"
  timeout = "60s"
  include = [
    "rules/prod/.*",
    "rules/common/.*",
  ]
}

prometheus "dev" {
  uri     = "https://prometheus-dev.example.com"
  timeout = "30s"
  include = [
    "rules/dev/.*",
    "rules/common/.*",
  ]
}

How to disable it

You can disable this check globally by adding this config block:

checks {
  disabled = ["alerts/absent"]
}

You can also disable it for all rules inside given file by adding a comment anywhere in that file. Example:

# pint file/disable alerts/absent

Or you can disable it per rule by adding a comment to it. Example:

# pint disable alerts/absent

If you want to disable only individual instances of this check you can add a more specific comment.

# pint disable alerts/absent($prometheus)

Where $prometheus is the name of Prometheus server to disable.

Example:

# pint disable alerts/absent(prod)

How to snooze it

You can disable this check until given time by adding a comment to it. Example:

# pint snooze $TIMESTAMP alerts/absent

Where $TIMESTAMP is either use RFC3339 formatted or YYYY-MM-DD. Adding this comment will disable alerts/absent until $TIMESTAMP, after that check will be re-enabled.