This is archived documentation for InfluxData product versions that are no longer maintained. For newer documentation, see the latest InfluxData documentation.
Alert handlers support match expressions that filters which alert events the handler processes.
A match expression is a TICKscript lambda expression. The data that triggered the alert is available to the match expression, including all fields and tags.
In addition to the data that triggered the alert metadata about the alert is available. This alert metadata is available via various functions.
| Name | Type | Description |
|---|---|---|
| level | int | The alert level of the alert event, one of ‘0’, ‘1’, ‘2’, or ‘3’ corresponding to ‘OK’, ‘INFO’, ‘WARNING’, and ‘CRITICAL’. |
| changed | bool | Indicates whether the alert level changed with this event. |
| name | string | Returns the measurement name of the triggering data. |
| taskName | string | Returns the task name that generated the alert event. |
| duration | duration | Returns the duration of the event in a non OK state. |
Additionally the vars OK, INFO, WARNING, and CRITICAL have been defined to correspond with the return value of the level function.
For example to send only critical alerts to a handler, use this match expression:
level() == CRITICAL
Examples
Send only changed events to the handler:
changed() == TRUE
Send only WARNING and CRITICAL events to the handler:
level() >= WARNING
Send events with the tag “host” equal to s001.example.com to the handler:
"host" == 's001.example.com'