Configure Time-Based Threshold Monitoring for Interface Groups

Time-Based Threshold Settings enable you to determine whether a threshold is reached for a particular duration of time (for example, the bandwidth utilization for an interface is above 90 percent for 20 out of 30 minutes).

To establish time-based threshold monitoring behavior for interfaces:

  1. Prerequisite. Before setting thresholds, analyze performance data over time to determine wise threshold settings for each Interface group.

  2. In the Interface Settings form, navigate to the Threshold Settings tab.
  3. Do one of the following:

    • To create a threshold definition, click the New icon and select Time-Based Threshold Settings.
    • To edit a threshold definition, select a row and click the Open icon.
    • To delete a threshold definition, select a row and click the  Delete icon.
  4. Select the Monitored Attribute you want to monitor and establish the threshold values for that attribute.

    When you configure thresholds using this technique, NNMi uses the assigned Interface Group as a filter (only monitoring the threshold for devices with at least one interface belonging to the specified Interface Group).

  5. Click  Save and Close to return to the Interface Settings form.
  6. Click  Save and Close to return to the Monitoring Configuration form.
  7. Click  Save and Close. NNMi applies your changes during the next regularly scheduled monitoring cycle.

    Note Threshold Incidents are disabled by default within NNMi to prevent Incident storms. If you are ready to generate Threshold Incidents, see Generate Performance Threshold Incidents (NNM iSPI Performance for Metrics). See also Custom Incident Attributes Provided by NNMi (Information for Administrators) for a description of the special custom incident attributes available in Threshold Incidents.

  8. See also Find Threshold Results.

Basic Time-Based Threshold Settings
Attribute Description
Monitored Attribute

In the Monitored Attribute drop-down list, select the attribute for which you want to establish a threshold configuration.

Tip Some of the choices in the Monitored Attribute selection list do not apply in this context.

See the tables in About Threshold Settings Provided by NNMi for information about which Monitored Attributes are available for Interface Groups.

A High Threshold situation occurs when:

The Monitored Attribute is greater than the High Value for at least the time specified in High Duration within the High Duration Window.

When these criteria are met, NNMi does the following:

  • Updates the Threshold's state value to  High for the appropriate Interface.
  • Generates the related incident (if one is Enabled ). If an incident is generated, NNMi closes that incident when the Threshold criteria are no longer met.
High Value

The value that above which becomes a threshold situation. Use one of the following:

  • Designate a percentage between 0.00 and 100.00.

    For special situations, the following values can be used:

    • 0.000000000000001 (or 1E-15 in Scientific Notation) for the smallest value greater than zero.
    • 99.99999999999999 for the highest value less than one hundred.
  • Designate any appropriate integer value (for example, a Management Address ICMP Response Time of 0 or greater milliseconds ).

The High Value must be greater than or equal to the designated Low Value.

If you use the highest possible value, the threshold is disabled because it cannot be crossed.

High Value Rearm

The High Value Rearm designates the lower boundary of the High Threshold range of values.

After entering a High threshold situation, when a returned value is below the specified High Value Rearm, the following happens (for Time-Based Thresholds):

  • The current polling interval does not contribute toward High Duration.
  • The criteria for High Duration and High Duration Window determine when the High Threshold situation ends.

Note The High Value Rearm must be less than or equal to the High Value and greater than or equal to the Low Value Rearm.

High Duration

Designate the minimum time within which the value must remain in the High range before the threshold state changes to High and (optionally) an incident is generated.

The High Duration should be equal to or greater than which ever currently configured Fault Polling Interval or Performance Polling Interval setting is influencing the Monitored Attribute you chose, because that is how often NNMi provides a data point. See the tables in About Threshold Settings Provided by NNMi for details. See the following topics for instructions about finding the current polling interval setting:

Tip Setting both the High Duration and High Duration Window to zero disables the High threshold.

High Duration Window

Designate the window of time within which the High Duration criteria must be met.

The value must be greater than 0 (zero) and can be the same as or greater than the High Duration value. NNMi uses a sliding window, meaning that each time the High Window Duration is reached, NNMi drops the oldest polling interval and adds the most recent.

Tip Setting both the High Duration and High Duration Window to zero disables the High threshold.

A Low Threshold situation occurs when:

The Monitored Attribute is lower than the Low Value for at least the time specified in Low Duration within the Low Duration Window.

When these criteria are met, NNMi does the following:

  • Updates the Threshold's state value to  Low for the appropriate Interface.
  • Generates the related incident (if one is Enabled ). If an incident is generated, NNMi closes that incident when the Threshold criteria are no longer met.

Low Value

The value that below which becomes a threshold situation. Use one of the following:

  • Designate a percentage between 0.00 and 100.00.

    For special situations, the following values can be used:

    • 0.000000000000001 (or 1E-15 in Scientific Notation) for the smallest value greater than zero.
    • 99.99999999999999 for the highest value less than one hundred.
  • Designate any appropriate integer value (for example, a Management Address ICMP Response Time of 0 or greater milliseconds ).

The Low Value must be less than or equal to the designated High Value.

If you use the minimum possible value, the Low threshold is disabled because it cannot be crossed.

Low Value Rearm

The Low Value Rearm designates the upper boundary of the Low Threshold range of values.

After entering a Low threshold situation, when a returned value is above the specified Low Value Rearm, the following happens (for Time-Based Thresholds):

  • The current polling interval does not contribute toward Low Duration.
  • The criteria for Low Duration and Low Duration Window determine when Low Threshold ends.

Note The Low Value Rearm must be greater than or equal to the Low Value and less than or equal to the High Value Rearm.

Low Duration

Designate the minimum time within which the value must remain in the Low range before the threshold state changes to Low and (optionally) an incident is generated.

The Low Duration should be equal to or greater than which ever currently configured Fault Polling Interval or Performance Polling Interval setting is influencing the Monitored Attribute you chose, because that is how often NNMi provides a data point. See the tables in About Threshold Settings Provided by NNMi for details. See the following topics for instructions about finding the current polling interval setting:

Tip Setting both the Low Duration and Low Duration Window to zero disables the Low threshold.

Low Duration Window

Designate the window of time within which the Low Duration criteria must be met.

The value must be greater than 0 (zero) and can be the same as or greater than the Low Duration value. NNMi uses a sliding window, meaning that each time the Low Window Duration is reached, NNMi drops the oldest polling interval and adds the most recent.

Tip Setting both the Low Duration and Low Duration Window to zero disables the Low threshold.