You can test the Node Checker functionality by ssh'ing into a node and removing the directories {red5pro}/work/red5Engine/ and {red5pro}/webapps/live. At the next scheduled check time, you should see something like the following in the Stream Manager's red5.log file:

2020-02-07 20:51:34,658 [pool-19-thread-7] WARN  
c.r.s.s.n.t.CorruptedNodeChecker - HOST: Node [id=9, host=, 
info=NodeInfo [id=9, nodeId=9, clientCount=0, publisherCount=0, 
restreamerCount=0, origins=[,], edges=[], 
connectionCapacity=300, extendedClientCount=0, lastTrafficTime=1581108660089, 
lastPing=1581108687980], state=INSERVICE, type=EDGE, availabilityZone=nyc3, 
name=qanode-nyc3-1581027653741] http/websocket service is down. Removing from