Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.
About alert rules
An alerting rule is a set of evaluation criteria that determines whether an alert instance will fire. The rule consists of one or more queries and expressions, a condition, the frequency of evaluation, and optionally, the duration over which the condition is met.
While queries and expressions select the data set to evaluate, a condition sets the threshold that an alert must meet or exceed to create an alert.
An interval specifies how frequently an alerting rule is evaluated. Duration, when configured, indicates how long a condition must be met. The alert rules can also define alerting behavior in the absence of data.