In the ozone script (hadoop-ozone/dist/src/shell/ozone/ozone), it sets ratis (netty) options for datanode. It should also set the options for om and scm.
Reduce garbage generated by non-netty threads in datanode ratis server
Disable netty resource leak detector in datanode
Warn that the netty useCacheForAllThreads feature may cause JVM GC pauses
GitHub Pull Request #1779