Active sessions ,RuntimeInstances and Scheduled_event

Why the screen of Active sessions doesn't show any data what does Runtime_ Instances screen used for? why I found some old Schedule events with status running and some completed?
1 answers

in order to activate active sessions you need to set PersistentSessions to true in the consol see link here

if you see scheduled events that are running then they must have failed and never completed. You must test them or schedule them again some time in the future.