HADOOP INSTALLATION

1) Go to VM  ( Virtual Machine )
2) root > apt-get update
3) root > sudo apt-get install openssh-server openssh-client
4) root > ifconfig
5) got to Putty login as root user
6) root > apt-get install python-software-properties
7) root > add-apt-repository ppa:webupd8team/java
8) root > apt-get update
9) root > apt-get install oracle-java8-installer
10) cd /   for coming at root directory
11) if multiple java version has installed
sudo update-alternatives --config javac

************ for completely remove OpenJdk from ubuntu ***
sudo apt-get purge openjdk-\* icedtea-\* icedtea6-\*


12) root > export JAVA_HOME=/usr/lib/jvm/java-8-oracle
13) root > echo $JAVA_HOME
14) root > adduser hduser sudo
15) root > groupadd hadoop
16) root > usermod -g hadoop hduser
17) root > su - hduser
18) hduser > ssh-keygen -t rsa -P ""
19) hduser > cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys
20) hduser > chmod 700 ~/.ssh
21) hduser > chmod 600 ~/.ssh/authorized_keys
22) hduser > ssh localhost
23) hduser > wget http://mirror.fibergrid.in/apache/hadoop/common/hadoop-2.7.2/hadoop-2.7.2.tar.gz
24) hduser > cd .. ( Goto previous direcotry)
25) hduser > tar -zxvf hadoop-2.7.2.tar.gz
26) hduser > sudo mv hadoop-1.2.1 /home/hduser/hadoop
27) hduser > sudo chown -R hduser /home/hduser/hadoop \
28) hduser > sudo echo "export HADOOP_HOME=/home/hduser/hadoop" >> /home/hduser/.bashrc\
29) hduser > sudo echo "export JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-amd64/" >> /home/hduser/.bashrc \

or
    hduser > sudo echo "export JAVA_HOME=/usr/lib/jvm/java-1.8/" >> /home/hduser/.bashrc \
30) hduser > echo "export PATH=\$PATH:\$HADOOP_HOME/bin" >> /home/hduser/.bashrc
31) hduser > echo "export PATH=\$PATH:\$JAVA_HOME/bin" >> /home/hduser/.bashrc \
32) hduser > sudo mkdir /home/hduser/hadoop/tmp \
33) hduser > sudo chown root /home/hduser/hadoop/tmp \
34) hduser > sudo chmod 777 /home/hduser/hadoop \
35) hduser > sudo chmod 777 /home/hduser/hadoop/tmp \
36) hduser > sudo sed -i 's/# export JAVA_HOME=\/usr\/lib\/j2sdk1.5-sun/export JAVA_HOME=\/usr\/lib\/jvm\/java-1.7.0-openjdk-amd64/' /home/hduser/hadoop/conf/hadoop-env.sh \
or
    hduser > sudo sed -i 's/# export JAVA_HOME=\/usr\/lib\/j2sdk1.8/export JAVA_HOME=\/usr\/lib\/jvm\/java-8-oracle/' /home/hduser/hadoop/conf/hadoop-env.sh \
37) hduser > sudo sed -i 's/# export HADOOP_OPTS=-server/export HADOOP_OPTS=Djava.net.preferIPv4Stack=true/' /home/hduser/hadoop/conf/hadoop-env.sh \
38) hduser > sudo sed -i "7d" /home/hduser/hadoop/conf/core-site.xml \
39) hduser > sudo sed -i "7i<property>\n<name>fs.default.name</name>\n<value>hdfs://localhost:9000</value>\n</property>\n<property>\n<name>hadoop.tmp.dir</name><value>/home/hduser/hadoop/tmp</value>\n</property>" /home/hduser/hadoop/conf/core-site.xml
40) hduser > sudo sed -i "7d" /home/hduser/hadoop/conf/mapred-site.xml \
41) hduser > sudo sed -i "7i<property>\n<name>mapred.job.tracker</name>\n<value>localhost:9001</value>\n</property>" /home/hduser/hadoop/conf/mapred-site.xml
42) hduser > sudo sed -i "7d" /home/hduser/hadoop/conf/hdfs-site.xml
43) hduser > sudo sed -i "7i<property>\n<name>dfs.replication</name>\n<value>1</value>\n</property>" /home/hduser/hadoop/conf/hdfs-site.xml \
44) hduser > ssh-keygen -b 2048 -t rsa -f /home/hduser/.ssh/id_rsa -q -N "" \
45) hduser > cat /home/hduser/.ssh/id_rsa.pub >> /home/hduser/.ssh/authorized_keys \
46) hduser > ssh-keyscan localhost >> /home/ubuntu/.ssh/known_hosts
47) chmod 700 ~/.ssh  ( ** Restrict access to the keys.**)
48) chmod 600 ~/.ssh/authorized_keys
49) ssh localhost (*****Verify if passowrd-less ssh is working/**)


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