When i do it i unmanage the device then mute alerts. I dont just mute alerts.
Here is a description of the documented/ expected behavior:
Muting alerts does not stop execution of repeatable actions
Updated March 27th, 2018
This article describes the alerting function wherein muting alerts do not work for managed objects if the "Repeat this action every X minutes until the alert is acknowledged" option is checked in the "Configure alert action" page.
NPM 12.x and UP
This is by design. The "Mute alert" was intended to prevent additional alerts from triggering, and not to prevent active alerts that have already triggered from performing their repeated alert actions.
From the Active Alerts page, find the muted alert and click the "Acknowledge" button to stop the repeating alert action.
D09h - Thanks for finding that, but that's not quite what I'm posting about. We've already figured out that muting an alert doesn't stop the 'repeat' actions once an alert has already been triggered
What I'm seeing is that these node down alerts appear to be ignoring the 'mute alerts' flag altogether. I'll mute one of these nodes, shut it down, and still get alerts for it. I'm not sure if it's because of how I've built the alert, or if it's because they're ICMP-monitored nodes instead of SNMP-monitored.
SNMP or ICMP shouldn't make a difference. I would triple check the custom property, and the alert logic. Possibly take some screenshots and post them here. Also look at the generated SWQL query to test how that is working. If all else fails I would consider opening a case and sending in the diagnostics of your SW instance.