Monitored nodes send AES a health status message every two minutes and AES stores it to the health stats table. AES agents process the health stats to create 'indicator' records, and the UI displays indicator records.
On AES server
- be sure that all agents are running
- enable debug logging on parseHealthMessage and parseHLTH0001 activities. Grab the logs and verify that health status messages are coming from the 'missing' monitored node(s)
If you can't find the messages from the server, then we need to debug the monitored node. Enable debugging on httpclient.wire.* classes -- lets be sure that health status messages are going out.