question how to verify if name node is in safe mode in Archives of Support Questions (Read Only)

how to verify if name node is in safe mode

mike_bronson7 — Thu, 04 Jan 2018 04:26:45 GMT

how to verify if name node is in safe mode ?

goal - in case of name node in safe mode , then bash script will perform the following steps on one of the masters machines

# su - hdfs  
$ hdfs dfsadmin -safemode get 
$ hdfs dfsadmin -safemode leave

second how to perform the steps as described in the bash script

is it ok to do the following :

su - hdfs -c "hdfs dfsadmin -safemode get"
su - hdfs -c "hdfs dfsadmin -safemode leave"

asirna — Thu, 04 Jan 2018 11:32:55 GMT

Yes. You can use the second way to achieve your task. You can also use the below to check if namenode is in SafeMode and leave conditionally.

su - hdfs -c "hdfs dfsadmin -safemode get" | grep ON
if [ $? -ne 0 ]
then
  su - hdfs -c "hdfs dfsadmin -safemode leave" 
fi

To run the above script, put the content in a file say xyz.sh

chmod +x xyz.sh
./xyz.sh

Thanks,

Aditya