https://community.cloudera.com/t5/Support-Questions/DATA-NODE-was-removed-from-Ambari-Due-to-Rackwareness/m-p/206919#M168880 <P>Hi Arpit, Thank you for the response. Actually our issue was resolved after refreshing client configs on the Namenode Host. Looks like the Namenode has cached the old configuration for DN and we were asked by HW support to Restart Namenode (or) if not possible, atleast refresh client config, we first refreshed client config that resolved our issue. </P> Mon, 24 Apr 2017 21:19:10 GMT ssanupindi 2017-04-24T21:19:10Z