Alert types
The available options are Count (default), Mean, Minimum, Maximum, and Ratio:
- Type
- Description
Count
- Fires an alert when a count threshold was exceeded.
Mean
- Fires on percentage deviations from the mean value. The mean is
calculated for the window of prior values of width
Alert Interval
. WhenAlert Interval
values accumulated, the current value is calculated for a 1 minute period immediately following the end of the Alert Interval. This current value is compared to the average of values over the Alert Interval, and an alert is generated if that value differs by the percentage that is specified as Alert Threshold or Warn Threshold. For example, if the specified threshold percentage is20
, then a current value of over 1.2 times the mean value triggers an alert.- The triggering percentage is interpreted as a positive or negative percentage, deviating from
the mean value, as defined by the
Direction
setting. See Alert configuration properties.
- The triggering percentage is interpreted as a positive or negative percentage, deviating from
the mean value, as defined by the
Minimum
orMaximum
- Fires on integer count deviations from either the minimum or maximum
value. The extremes are for the window of prior values of width
Alert Interval
. WhenAlert Interval
values accumulated, the current value is compared to the Minimum or Maximum of values over that interval and an alert is generated if that value differs by the count that is specified asAlert Threshold
orWarn Threshold
. The triggering deviation can be specified as either positive or negative. The available options are Positive (default) and Negative. Selecting Negative sends a flag to signal that this is a negative alert. This results in alerting when less than, rather than greater than. Ratio
- Fires a warning or alert when the ratio of the incidences of this event to an arbitrarily selected denominator event exceeds a fractional threshold. When the Ratio option is selected, percentage signs appear next to the Threshold field values. The ratio is X/Y, where Y is a counter-event. Select a sampling interval that yields actual statistically meaningful results. See Configuring ratio alerts.