Hadoop single node cluster in ease.......

***Cent OS 6.4 ( 32bit/64bit) configuring CDH4***
Single Node Cluster:---

* Install centos iso image in vm workstation.

* Download java1.6 based on Cent OS 32 bit or 64 bit

eg : 32 bit
          jdk-6u43-linux-i586-rpm.bin

* Give executable permission to jdk-6u43-linux-i586-rpm.bin

$chmod 755 jdk-6u43-linux-i586-rpm.bin

* Install java from root user(where java is there)

#./jdk-6u43-linux-i586-rpm.bin

* Export java home
#export JAVA_HOME=/usr/java/jdk1.6.0_43

* Download required hadoop version
ex:hadoop-1.0.3.tar.gz

* Switch to other user   [ To add user:
                                               Switch to root user and
                                               #su adduser <username>  (default group of user is root)]

#su <username>
password:<password>

* Unzip hadoop tar file           
$tar -zxvf hadoop-1.o.3.tar.gz

* Making hadoop recognize java
 cd /hadoop/conf
$vi hadoop-env.sh
and add following line
export JAVA_HOME=/usr/java/jdk1.6.0_43     //your java will be installed here
save and quit

* Configuring HADOOP_HOME directory to hadoop instalation directory
export HADOOP_HOME

* Goto your home dir
$cd ~

open .bashrc file in vi editor and add following lines
export HADOOP_HOME=<hadoop installed location>
export PATH=$PATH:$HADOOP_HOME/bin

Note:
* Add user to sudoers file
goto root user and open /etc/sudoers file and add following line
<username> ALL=(ALL)    NOPASSWD:ALL

*Making update-alternatives working
add following line to .bashrc file in u r home dir

*export PATH=$PATH:/sbin:/usr/sbin:/usr/local/sbin

*Make jps running

goto home $cd ~

open .bashrc file and add following line

export PATH=$PATH:/usr/java/jdk1.6.0_43/bin

*Set all configurations

#vi /home/training/hadoop/hadoop-1.0.3/conf/core-site.xml
<property>
  <name>fs.default.name</name>
  <value>hdfs://localhost:8020</value>
</property>

#vi /home/training/hadoop/hadoop-1.0.3/conf/mapred-site.xml

<property>
  <name>mapred.job.tracker</name>
  <value>localhost:8021</value>
</property>

#vi /home/training/hadoop/hadoop-1.0.3/conf/hdfs-site.xml

<property>
  <name>dfs.replication</name>
  <value>1</value>
</property>

Format the namenode [Format your name-node when you set up your cluster for first time]

$hadoop namenode -format

*Start all the services

$/home/training/hadoop/hadoop-1.0.3/bin/start-all.sh
                                      or
    You can directly start services from your home as start-all.sh

*Open browser and check weather the services start or not

        http://localhost:50070         or                  http://localhost:50030


*Installing eclipse in node

change to root user and do the following
#

download eclipse
   eg.: eclipse-java-europa-winter-linux-gtk.tar.gz

create a dir eclipse under /home/training

copy the downloaded file to eclipse folder and untar the file

tar -zxvf eclipse-java-europa-winter-linux-gtk.tar.gz

*Change permissions for eclipse dir

chmod -R +r /opt/eclipse

*Create Eclipse executable on /usr/bin path

touch /usr/bin/eclipse

chmod 755 /usr/bin/eclipse


## Open eclipse file with your favourite editor ##
nano -w /usr/bin/eclipse

## Paste following content to file ##
#!/bin/sh
export ECLIPSE_HOME="/home/training/eclipse"

$ECLIPSE_HOME/eclipse $*


*Bring eclipse icon on desktop

## Create following file, with our favourite editor ##
/usr/share/applications/eclipse.desktop

## Add following content to file and save ##
[Desktop Entry]
Encoding=UTF-8
Name=Eclipse
Comment=Eclipse SDK 4.2.1
Exec=eclipse
Icon=/home/training/eclipse/icon.xpm
Terminal=false
Type=Application
Categories=GNOME;Application;Development;
StartupNotify=true

after successful installation goto Applications->programming->eclipse->right click and ->addthis launcher to desktop

launch eclipse by double clicking eclipse icon on desktop

click on new project-->select mapreduce project-->click on configure Hadoop Install dir adnd give <hadoop install location>