Change detection management planning helps ensure that Data Aggregator detects and monitors device reconfigurations in your environment according to your needs.
Q: Can’t I just set the Change Detection rate to 5 mins so that DA will quickly pick up changes?
The product does not prevent such a setting, but in most cases it needlessly consumes system resources, and could limit how well the hardware will scale. Choose a change detection setting that is appropriate based on the likelihood of changes, and importance of reflecting the updates in DA. For example in many environments interface reconfiguration is done only at specific periods of maintenance, checking for change once a day is likely enough. Depending on the nature of the metric family checking for changes may not even be needed. Consider how often the amount of memory in a router changes for example
Q: Do I still need change detection if I schedule inventory discovery daily?
Yes. Inventory discovery does not re-evaluate all of the metric families for a device. For example a scheduled inventory discovery will not cause new interface items to be added to a device.
Q: Do I need change detection set up for everything?
It depends largely on business practices, if your company has very good change control policies, and you will get a ticket when a device must be updated you may choose to use manual Update Metric Family option instead of change detection.
Q: If I have an MP with the Interface Metric family specified and a Detection Rate of 24 hours what does that mean?
- Within a 24 hour period DA will check each device once for changes in the configuration of the Interface metric family. This can include things like:
- Add new interfaces
- Remove old interfaces
- Config changes like ifSpeed, ifAlias etc…