Heartbeat is lost between DA and DR. We can see that the DA stops sending the hear beats.
This was an issue with the network connections being closed due to new firewall hardware.
DA would keep sending the heartbeat requests to the DR but the connection was closed by the firewall.
Release : 20.2
Component : IM Reporting / Admin / Configuration
This caused the DA to timeout the DR nodes and shutdown.
To correct this we added this line to the /opt/IMDataAggregator/apache-karaf-2.4.3/etc/dbconnection.cfg.
This will close and reestablish the connection every 5 minutes so the heartbeats will not time out.
dbpollMaxAgeInMS = 900000