How to recover Task Tracker and Job Tracker in hadoop?

Question

I had installed hadoop on a single node. And the OS I am using is Ubuntu. I had created a hduser for 1st very successfully. When I removed the existing hduser and created a new hduser in the same system, I am unable to get the task-tracker and job-tracker.

$jps
3750 DataNode
5328 Jps
3978 SecondaryNameNode
3529 NameNode
5156 TaskTracker

Now, my problem is here I am unable to find the Job Tracker. And when I tried using the localhost port numbers, the Task tracker and Job Tracker are not working. What is the reason? How can I recover them?

Answer 1

The following steps may helpful:

1. Look into the log of your JobTracker and TaskTracker. It is usually in your $HADOOP_HOME/logs/ directory for more details. Or you can paste the log here, so that other guys can help you find out. Your current description have little information
2. use netstat to show if any java process have bind the port you have tried to use.