Werk #12392: HW/SW Inventory: Single values or table columns can be kept longer than their validity period
|Title||HW/SW Inventory: Single values or table columns can be kept longer than their validity period|
|Date||Jul 26, 2021|
|Checkmk Editon||Checkmk Raw (CRE)|
|Compatibility||Compatible - no manual interaction needed|
The mk_inventory agent plugin collects static data like BIOS settings, information about the operation system, installed packages and others. The collected data has a validity period and will be removed if no new data is provided by the plugin.
Hosts or applications may be down or unreachable due to maintenance work and do not provide data anymore. Such situations lead to empty tree entries.
In order to counteract such situations single values or table columns can be kept longer than their validity period from the previous tree via the ruleset "Retention intervals for HW/SW inventory entities".
One advantage is that tree entries are not missing in reports.
If the host provides data again the new data is used, of course.
The retention information about how long single values or table columns are kept is displayed behind the single value keys resp. in the headers of the table columns.
Retention intervals will be removed completely if there is no ruleset "Retention intervals for HW/SW inventory entities" anymore.
Assume the fields hardware.memory::total_ram_usable and networking.interfaces::index are currently not contained in the agent data, and their validity periods are expired. If there are retention intervals configured for these fields, they will not dissappear from the inventory, but their respective headers display "Total usable RAM (x left)" and "Index (y left)". If the retention intervals are expired the headers show "Total usable RAM (outdated)" respecively "Index (outdated)".
This feature is only available for inventory plugins programed against the new API: If you want to keep table columns we must know which columns identify a row. This information is not available for legacy inventory plugins, which would lead to unexpected, incomprehensible and non-transparent results regarding the inventory history, filtering or merging other trees.
This means that you have to migrate legacy inventory plugins to the new API which generate TableRows (or Attributes).