Comment 1 for bug 1786042

The controller VM's are provisioned with low memory.
[heat-admin@overcloud-contrailcontroller-1 ~]$ free -h
              total used free shared buff/cache available
Mem: 15G 13G 273M 4.8M 1.9G 1.6G
Swap: 0B 0B

This is not enough to run analytics_cassandra and config_cassandra in the same VM.
I am noticing OutOfMemory Errors in cassandra logs as well.
INFO [ScheduledTasks:1] 2018-08-08 14:27:36,704 MessagingService.java:1238 - MUTATION messages were dropped in last 5000 ms: 125 internal and 121 cross node. Mean internal dropped latency: 545919 ms and Mean cross-node dropped latency: 537531 ms
java.lang.OutOfMemoryError: Java heap space
Dumping heap to java_pid1.hprof ...
Unable to create java_pid1.hprof: Permission denied

#
# java.lang.OutOfMemoryError: Java heap space
# -XX:OnOutOfMemoryError="kill -9 %p"
# Executing /bin/sh -c "kill -9 1"...
os::fork_and_exec failed: Cannot allocate memory (12)
INFO [ScheduledTasks:1] 2018-08-08 14:35:22,034 MessagingService.java:1238 - REQUEST_RESPONSE messages were dropped in last 5000 ms: 0 internal and 3 cross node. Mean internal dropped latency: 0 ms and Mean cross-node dropped latency: 0 ms