MCS alarm policy created for Disk(s) profile to override Default Disk(s) profile generates 2 alarms

Document ID : KB000125618
Last Modified Date : 31/01/2019
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Issue:
If it is necessary to define separate thresholds for Disk(s) templates applied to a Monitoring Configuration Service (MCS) monitoring group, it is possible to get 2 alarms for the disk metric from MCS.
The same thing will occur for any alarm policy created at the device level if an alarm policy already exists for the monitored metric at the group level in MCS.
Environment:
UIM/UMP 9.02
Cause:
In the 9.02 UIM/UMP release, alarm policies associated with (Enhanced) MCS templates do not have any precedence associated with them.  For this reason, if multiple alarm polices are associated with a metric monitored on a single robot it is possible to get multiple alarms for this metric.

Some use case examples:

Example 1:
A robot is a member of multiple monitoring groups and the same (Enhanced) MCS template is applied to all groups.  If the metric exceeds the configured thresholds in the alarm policies associated with the template applied, then multiple alarms will be raised for this metric when it exceeds the configured thresholds.

Example 2:
Create a Default Disk(s) (Enhanced) template for a monitoring group in the UMP USM portal.
Create a Disk(s) (Enhanced) template for a single file system for the same group.
Create a new alarm policy for the one filesystem for one of the devices in the monitoring group.
2 alarms will be raised for the monitored metric if the metric exceeds the configured thresholds - one from the group level alarm policy and the second from the device level alarm policy
Resolution:
This is the current design of Alarm Policy handling in the 9.02 GA release and cannot be changed.

With the release of the UIM 9.02 Service Pack 1 (SP1), the ability to add a precedence will be added to alarm policies.  With this change, only alarm policies for the same metric applied to a robot will generate multiple alarms if the precedence of the alarm polices are identical.  If the precedence is different for all alarm polices, then only the policy with the highest precedence will be applied.  In the 9.02 SP1 release,  alarm policies created by default at the device level will have a higher precedence than alarm policies created by default at the group level.