@Namit Maheshwari
yes, it is possible - couple of ways you can do this are:
1. You can do it from JAVA code by using JMX Apis.
2. You can connect to namenode:httpport;/jmx and get a json based response.
3. You can configure a Namenode/Datanode Metrics log file which will dump into a file which you can parse
I am probably missing some more ways :), hope this helps you.