The exiting of any Cassandra microservice is not normal.
Support, I have the Sysview MTC zLinux appliance running and after being up for about 10 hours on of the cassandra database instances exits. Is this normal?
MAINFRAME OPERATIONAL INTELLIGENCE 2.0
Root cause of the exited container was insufficient memory. The kernel killed the cassandra3 process due to lack of memory. This was identified in the syslogs/var/log/messages file. Sample message for searching was "Sep 20 19:32:33 SVN0_MFOI kernel: Out of memory: Kill process 5320 (java-run) score 212 or sacrifice child"
Increasing site's installation memory from 39GB to recommended 64GB.