Hadoop hdfs tips and tricks
Active namenode in a cluster
# lookup active nn
nn_list=`hdfs getconf -namenodes`
echo Namenodes found: $nn_list
active_node=‘’
#for nn in $( hdfs getconf -namenodes ); do
for nn in $nn_list ; do
echo Checking nn for active: $nn
if hadoop fs -test -e hdfs://$nn/ ; then
echo Found active nn
active_node=$nn
break
fi
done
echo active nn is $active_node
