This is the documentation for CDH 4.6.0.
Documentation for other versions is available at Cloudera Documentation.

Replacing the non-HA JobTracker with the HA JobTracker

This section provides instructions for removing the non-HA JobTracker and installing the HA JobTracker.

  Important:

The HA JobTracker cannot be installed on a node on which the non-HA JobTracker is installed, and vice versa. If the JobTracker is installed, uninstall it following the instructions below before installing the HA JobTracker. Uninstall the non-HA JobTracker whether or not you intend to install the HA JobTracker on the same node.

Removing the non-HA JobTracker

You must remove the original (non-HA) JobTracker before you install and run the HA JobTracker. First, you need to stop the JobTracker and TaskTrackers.

To stop the JobTracker and TaskTrackers:

  1. Stop the TaskTrackers: On each TaskTracker system:
    $ sudo service hadoop-0.20-mapreduce-tasktracker stop
  2. Stop the JobTracker: On the JobTracker system:
    $ sudo service hadoop-0.20-mapreduce-jobtracker stop
  3. Verify that the JobTracker and TaskTrackers have stopped:
    $ ps -eaf | grep -i job
    $ ps -eaf | grep -i task

To remove the JobTracker:

  • On Red Hat-compatible systems:
$ sudo yum remove hadoop-0.20-mapreduce-jobtracker
  • On SLES systems:
$ sudo zypper remove hadoop-0.20-mapreduce-jobtracker
  • On Ubuntu systems:
sudo apt-get remove hadoop-0.20-mapreduce-jobtracker

Installing the HA JobTracker

Use the following steps to install the HA JobTracker package, and optionally the ZooKeeper failover controller package (needed for automatic failover).

Step 1: Install the HA JobTracker package on two separate nodes

On each JobTracker node:

  • On Red Hat-compatible systems:
$ sudo yum install hadoop-0.20-mapreduce-jobtrackerha
  • On SLES systems:
$ sudo zypper install hadoop-0.20-mapreduce-jobtrackerha
  • On Ubuntu systems:
sudo apt-get install hadoop-0.20-mapreduce-jobtrackerha

Step 2: (Optionally) install the failover controller package

If you intend to enable automatic failover, you need to install the failover controller package.

  Note:

The instructions for automatic failover assume that you have set up a ZooKeeper cluster running on three or more nodes, and have verified its correct operation by connecting using the ZooKeeper command-line interface (CLI). See the ZooKeeper documentation for instructions on how to set up a ZooKeeper ensemble.

Install the failover controller package as follows:

On each JobTracker node:

  • On Red Hat-compatible systems:
$ sudo yum install hadoop-0.20-mapreduce-zkfc
  • On SLES systems:
$ sudo zypper install hadoop-0.20-mapreduce-zkfc
  • On Ubuntu systems:
sudo apt-get install hadoop-0.20-mapreduce-zkfc