Zookeeper Installation

A. Pre-Requisite

1. Hadoop

B. Zookeeper Installation

1. Download ZooKeeper from : http://www.apache.org/dyn/closer.cgi/zookeeper/ (downlaod the latest stable version !)

2. Goto Downloads folder: launch terminal -> cd <download path> (ex: cd /home/hduser/Downloads)

3. Extract: tar -xzf zookeeper-<version>.tar.gz (ex: tar -xzf zookeeper-3.4.5.tar.gz)

4. Change directory name: mv zookeeper-<version>/ zookeeper/

5. Move zookeeper to a common directory where all hadoop tools installed: sudo mv zookeeper/ /usr/hadoop/.

6. Change Ownership: sudo chown -R hduser:hadoop /usr/hadoop/zookeeper/

7. Create a directory under /tmp and change ownership to to the user under which zookeeper installed : cd /tmp -> sudo mkdir zookeeper  -> sudo chown -R hduser:hadoop zookeeper (This directory to store the in-memory database snapshots & the transaction logs)

8. Edit zoo config: In the distribution zoo_sample.cfg exists. Create a copy of it as zoo.cfg & edit: cd <Zookeeper installation path>/conf; cp zoo_sample.cfg zoo.cfg; vi zoo.cfg to configure the datadir & other configurations as per below:
tickTime=2000
dataDir=/var/lib/zookeeper
clientPort=2181

Upon any change save the file & exit (esc :wq)

9. Now login / change as hduser (zookeeper installation user)

10 cd (to goto home directory)

11. vi .bashrc
add below environment variables:
ZOOKEEPER_HOME=/usr/hadoop/zookeeper
export ZOOKEEPER_HOME
PATH=$PATH:$ZOOKEEPER_HOME/bin
export PATH
Upon adding above lines, save & exit from .bashrc (esc :wq)

12. source .bashrc

13. Start ZooKeeper server: zkServer.sh start

14. Zookeeper's command line tools:

zkCli.sh localhost ls /zoo