Q:

Hadoop in AWS EMR: Will closing terminal kill hadoop job? 

Is it safe to close my terminal or turn off my computer without killing my Hadoop job? 
I am in the middle of a Hadoop job running via a cluster on Amazon's Elastic Map Reduce.  I have my terminal open, where I am ssh'd into my master node.  When I try to close my terminal, I get a warning that all processes will be killed.  Will this kill my Hadoop job as well?  Or can I power off my computer and ssh again later?  Do I need a special tool (like tmux) to do this?  
If it matters, I am using the default (bin/bash) terminal in Ubuntu 13.10.  I started the job with a Pig script. 

A:

No, you can happily kill the terminal .  The mapreduce job is running on the EMR cluster and will continue to do so.  You could come back , log into the master node and check lynx http://localhost:9100 for jotracker status anytime.  To kill a hadoop job you have to run the command hadoop job -kill jobflowid .  So, moot point is - at any time you can log into the jobtracker and see the status of your job. Also note that jobtracker's port address 9100 is default on EMR cluster.   Cheers.. 

