Hello, Looking at the System Administrator’s Guide <https://nifi.apache.org/docs/nifi-docs/html/administration-guide.html>, I see that you recommend setting vm.swappiness = 0 in /etc/sysctl.conf. This is fine in most cases, but must be avoided on RHEL 6.4 through 6.7.
On RedHat kernels pre-2.6.32-642, there's a bug which can cause the OOM killer to aggressively kill processes even when RAM is still available and swap is unused. See this RedHat article <https://access.redhat.com/solutions/1149413> for more information. (A RedHat support login is required; if you don't have one, please contact me off-list.) I kindly recommend you add a note to your docs advising users not to apply this setting on affected kernels. Thank you! - Ron
