@bvishal, as this is an older post, you would have a better chance of receiving a resolution by starting a new thread. This will also be an opportunity to provide details specific to your environment that could aid others in assisting you with a more accurate answer to your question. You can link this thread as a reference in your new post. ... View more

username: root password: hadoop UNIX password: hadoop set new password: confirm new passord: ... View more

In case ambari API doesn't help. You can use following SQL queries to abort hung/queued/pending operations directly from ambari database.   1) Stop Ambari-Server   ambari-server stop   2) Take backup of ambari database before making any changes to ambari db 3) Check IN_PROGRESS, QUEUED and PENDING operations.   ambari=> select task_id,role,role_command from host_role_command where status='IN_PROGRESS'; ambari=> select task_id,role,role_command from host_role_command where status='QUEUED' limit 100; ambari=> select task_id,role,role_command from host_role_command where status='PENDING';   4) Abort Operations   ambari=> update host_role_command set status='ABORTED' where status='QUEUED'; ambari=> update host_role_command set status='ABORTED' where status='PENDING'; ambari=> update host_role_command set status='ABORTED' where status='IN_PROGRESS';   5) Start ambari-server   ambari-server start       ... View more

You can try logging into the admin user and restart datanodes from the actions bar in Dashboard. That worked for me. May work for you too. ... View more

works for me too ... View more

Great to hear that 🙂 ... View more

If I wanted to list the top 10 tweets could I include a where clause in the Emit of the reducer method, something along the lines of: Emit(terms t, LIMIT(DESC(count sum),10)? ... View more

Hi @Arpit Agarwal, That is my understanding as well. Thanks for a short and to the point answer. ... View more

I tried doing that but it's not working for me. ... View more

Here is a great writeup on file compression in Hadoop - http://comphadoop.weebly.com/ ... View more