We enable Namenode High Availability through Cloudera Manager, using
Cloudera Manager >> HDFS >> Action > Enable High Availability >> Selected Stand By Namenode &a
Looks like you are using wrong client configuration in /etc/hadoop/conf directory. Sometimes Cloudera Manager (CM) deploy client configurations option may not work.
As you have enabled NN HA, you should have valid core-site.xml and hdfs-site.xml files in your hadoop client configuration directory. For getting the valid site files, Go to HDFS service from CM Choose Download client configuration option from the Actions Button. you will get configuration files in zip format, extract the zip files and replace /etc/hadoop/conf/core-site.xml and /etc/hadoop/conf/hdfs-site.xml files with the extracted core-site.xml,hdfs-site.xml files.