Elasticsearch - node validation exception bootstrap checks failed on CentOS 6.x

During setting up of elasticsearch 5.x cluster, I encountered "bootstrap checks failed" error as given below:

[2017-02-09T09:47:32,004][ERROR][o.e.b.Bootstrap] [elk5-master-node] node validation exception
bootstrap checks failed
system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk
[2017-02-09T09:47:32,022][INFO ][o.e.n.Node               ] [elk5-master-node] stopping ...
[2017-02-09T09:47:32,163][INFO ][o.e.n.Node               ] [elk5-master-node] stopped
[2017-02-09T09:47:32,163][INFO ][o.e.n.Node               ] [elk5-master-node] closing ...
[2017-02-09T09:47:32,181][INFO ][o.e.n.Node               ] [elk5-master-node] closed


After going through github issue(s), I realized that "secomp" on CentOS 6 is not available and you have to disable it.

There is a discussion on it here -  https://github.com/elastic/elasticsearch/issues/22899

So, add the following settings in elasticsearch.yml:
bootstrap.system_call_filter: false

and start elasticsearch again.