How and when are acknowledged alerts purged from the Orion database? Is that controlled by the Events retention setting on the Polling Settings page?
Alerts are only cleared from the database when they are reset. If there is not a reset condition for the alert, and it stays in a triggered state, the alert will remain. You can try disabling the alert then re-enabling it, but again, if the devices is still in the trigger condition, it will show back up once the alert is enabled again.
I think I am with you Matthew, but let me see if I understand your answer. Let's use a simple node status alert as an example. If I set the alert to notify me when a node goes down, but do not set a reset condition, will the alert be deleted from the ActiveAlerts table in the Orion database when the node comes back up?
Unless you have the reset set to "Reset when conditions are no longer true" then no, the alert will not clear as there is no defined reset condition.