Dear Sai,
Hope you are doing well
Kindly fire below commands one by one to restart the cluster.
sudo service hadoop-master stop
sudo service hadoop-master start
hadoop dfsadmin -safemode leave
sudo jps
After this, you can proceed
Hope this resolves your query
In case of any further issue,feel free to revert.
Regards
Sumit Anand
edureka! Solution Team
Website - www.edureka.co
Edureka claims 1st position at Deloitte's Technology Fast 50 India 2014