subcluster count of custom situation definition seems representing wrong value

Products

• DX OI SaaS

Issue/Introduction

subcluster count of custom situation definition is not reporting correct value. It seems like it is showing alarm message count. This information is being sent to notification channel (ticket) that is coming from the custom situation name and not from the message template. In custom situation name do not see any option to add subcluster count.

Environment

DX SAAS

Resolution

In the case of a custom situation name, the count(message) operation selects unique messages from the subclusters and counts them, which is why the count appears as 3 in the name. 

If you prefers to see the alarm count in the custom situation name, it's recommended to use {count(TotalAlarm)}, as this will correctly reflect the number of alarms involved in the situation.

Additional Information

We use following formula for noise reduction calc : (100D - ((clusterCount * 100D) / (alarmCount))) and at overview page clusterCount is always considered as 1.  

Example:

SubClusters Count: A total of 81 subclusters were formed as part of a single situation cluster. This is why the main situation page displays the subcluster count as 81.

Situation Custom Name: The {count(message)} operation was used to extract unique messages from the 81 subclusters. Since there are 2 unique messages, the situation name reflects this count as 2.

Noise Reduction: On the overview page, noise reduction is calculated at the single cluster level. The ClusterCount is always considered as 1. The formula used is:
100 - ((ClusterCount * 100) / AlarmCount)
Substituting values: 100 - ((1 * 100) / 81) = 98.77