Managing the Infrastructure › Device Reconfiguration › How to Manage Change Detection

How to Manage Change Detection

Change detection management planning helps ensure that Data Aggregator detects and monitors device reconfigurations in your environment according to your needs. You can plan ahead for any device reconfiguration when you first set up Data Aggregator to discover new devices. Or, you can edit these options at any time after devices are discovered.

The choices that you make are based on:

• The likelihood of change.
• The frequency of change you anticipate.
• Your tolerance for how far out-of-date your data is.

There can be metric families, such as CPUs, that you want to monitor for reconfiguration infrequently. For other metric families that are more dynamic, such as virtual systems, choose a more frequent rate.

The basic process for setting change detection is:

1. Create or edit a custom monitoring profile. (You can also copy a factory monitoring profile and edit the copy.)
2. Select Enable Change Detection and set the Change Detection Settings, Rate in the monitoring profile.

   The Change Detection Settings, Rate option is used to set the frequency at which Data Aggregator checks for changes. The rate of detection can be set in minutes or hours. By default, the rate is set to 24 hours.

   Note: Consider how frequently the metric family is likely to change, and how many devices the monitoring profile is applied to. Avoid setting change detection rates that are more frequent than necessary.

3. Update the Data Aggregator representation of the metric families.

   After you set the change detection rate, you have two options for correcting the Data Aggregator configuration: automatic or manual update of the metric families. This option does not update the metric families. Instead, it updates the representation of the metric families by making sure that the correct set of components is being monitored.

   • Selecting the Automatically Update Metric Families option (selected by default) means that you do not have to intervene when a reconfiguration is detected. Data Aggregator automatically starts monitoring any new components and retires any components that are no longer detected when a reconfiguration event occurs.

     View the Events Display dashboard to see reconfiguration events:

     • If the components have changed for a device, an event is generated on the associated device. This event describes that a component change has been detected and will be applied after a short period.
     • After component reconciliation is applied, another event is generated. This event describes how many components were added, retired, and remained unchanged.
   • Deselecting the Automatically Update Metric Families option means that Data Aggregator does not automatically start monitoring new components or retire old components.

     View the Events Display dashboard to see reconfiguration events:

     • If the components have changed for a device, an event is generated on the associated device. This event describes that a component change has occurred but reconciliation has not occurred.

     To have the reconfiguration changes applied, manually click the Update Metric Family button on the Polled Metric Families page for a device.

4. To make the monitoring profile active, assign the custom monitoring profile to a device collection.

Examples:

• If you are aware that your environment will be undergoing significant maintenance, you can turn off the automatic update until the major maintenance is complete. For small, regular changes, enabling the automatic update feature helps ensure your Data Aggregator stays up to date.
• Monitoring profiles are assigned to device collections that contain devices. If you have special devices that you want to monitor differently, create a custom device collection for these special devices and assign a custom monitoring profile with the change detection settings you want. For example, you can monitor critical core routers more frequently than other routers by creating a critical core routers device collection and assigning a custom monitoring profile that performs change detection hourly. Other routers can remain in the 'All Routers' device collection using the factory monitoring profile (with no change detection) or a custom monitoring profile that you set to less frequent change detection.

More information:

Discovery and Polling

Update Device Reconfiguration Manually

Update Device Reconfiguration Automatically