I'm looking for nodes that have been abandoned in our environment. Could some one point me in the right direction for a reliable source to pull this data from. Under Orion.Nodes is LastSystemUpTime but I believe that is for non ICMP polled nodes we noticed a lot of NULL values and old values for Node that were currently up. I came across some custom SQL reports that had some complex stuff going on to find node outage duration but I couldn't translate them into SWQL.
If you just want to find nodes that have not responded in the last 30 days, you could use a query like this:
SELECT NodeID, MAX(Availability) AS MaxAvailability
WHERE DateTime > ADDDAY(-30, GETUTCDATE())
GROUP BY NodeID
HAVING MAX(Availability) = 0