The KeepAlive module is a special module that updates the Data server and changes to “down” status when the Software Agent stops reporting during the double of the configured interval.
It is possible that if the agent has a connectivity problem in some specific moment and it cannot send the XML to the server, this module will appear during some period in a critical status although the server continues active and most probably if there is also a Host Alive (Ping) module inside that agent, the Host Alive module will be in a different status than the KeepAlive module.
In case there is any incidence of software agents queuing, there could also be changes in the status of these modules. It can give us the signal that we have performance problems in the server and/or we have some connectivity problem between the agents and the server.