Sorry for the late reply @DavidTurner
In my log continuously i'm getting below error only,
[2018-10-22T11:36:42,744][INFO ][o.e.d.z.ZenDiscovery ] [datanode1-ac020034.com] failed to send join request to master [{node-ac020035.com}{JI7hjoheRQW0-WDje0lWgg}{HLycvNZbQJe1GXFCtTCv3w}{10.x.xxx.14}{10.x.xxx.14:9300}], reason [RemoteTransportException[[node-ac020035.phx.aexp.com][172.19.0.2:9300][internal:discovery/zen/join]]; nested: ConnectTransportException[[datanode1-ac020034.phx.aexp.com][172.18.0.3:9301] connect_timeout[30s]]; ]