Availability alert raised 35 minutes after last good poll

Products

• CA Infrastructure Management
• CA Performance Management - Usage and Administration
• DX NetOps

Issue/Introduction

IF's last good poll was at 21:40. Availability alert configured to fire if <100% for 300 seconds. This alert should have fired at 21:45. It did not until 22:15.

Environment

Release : 3.7

Component : IM Reporting / Admin / Configuration

Resolution

this specific issue the event came in on the first data point that has availability equal to 0 percent. For some reason there was no polling for this interface from 20:45 to 22:15. Once it got its first data point with 0 Percent the event triggered. You need to have valid data points for an event to trigger.  

From the report. 
4/8/2020 21:35 EDT    100 Percent
4/8/2020 21:40 EDT    100 Percent
4/8/2020 21:45 EDT
4/8/2020 22:15 EDT    0 Percent
4/8/2020 22:20 EDT    0 Percent
4/8/2020 22:25 EDT    0 Percent