Old interfaces are never removed from Foreman DB
Hosts like hypervisors or docker hosts may often change interfaces (e.g. network bridges) which confuses Foreman and during fact import it creates more and more interfaces, old are never deleted. After some time when a host passes thousands of interfaces, due to O(n^2) one fact upload can take several minutes of processing.
We need to delete old interfaces from Foreman database, either during fact upload directly or on schedule (those that hasn't been updated for a while).
The behvior is really bad, Foreman eats up all memory until passenger process is restarted, which can take a while (non-Enterprise version do not have maximum memory setting).