We enable Namenode High Availability through Cloudera Manager, using
Cloudera Manager >> HDFS >> Action > Enable High Availability >> Selected Stand By Namenode &a
Got it resolved. wrong config was linked to "/etc/hadoop/conf/" --> "/etc/alternatives/hadoop-conf/" --> "/etc/hadoop/conf.cloudera.mapreduce1"
It has to be "/etc/hadoop/conf/" --> "/etc/alternatives/hadoop-conf/" --> "/etc/hadoop/conf.cloudera.mapreduce"