The Data Aggregator process exited unexpectedly.
In the /var/log/messages we see an entry similar to:
MMM DD HH:MM:SS daHostname systemd[1]: dadaemon.service: main process exited, code=killed, status=9/KILL
But we do not see any indication that the Linux kernel out of memory killer terminated the process.
The Data Aggregator karaf.log ends abruptly at the same time.
There are no DA_HOME/apache-karaf-*/hs_err.*.log files present indicting that the process ran out of physical memory.
An administrator was killing the dadaemon process.
Release : 20.2
Component : IM Data Aggregator
The Data Aggregator processes should be stopped gracefully if needed, not killed.