hadoop-setup

Download: it from http://www.apache.org/dyn/closer.cgi/hadoop/common/hadoop-2.6.5/hadoop-2.6.5.tar.gz

Supported Platforms:

    GNU/Linux is supported as a development and production platform. Hadoop has been demonstrated on GNU/Linux clusters with 2000 nodes.

    Windows is also a supported platform but the followings steps are for Linux only. To set up Hadoop on Windows, see wiki page.

Required Software: For installation steps of required software, refer os specific section under System Administration:

    Java™ must be installed. Recommended Java versions are described at HadoopJavaVersions.

    ssh must be installed and sshd must be running to use the Hadoop scripts that manage remote Hadoop daemons.

Configure:

1. Extract downloaded file:

    tar -xzf hadoop-2.6.5.tar.gz

   Standalone:
Hadoop is configured to run in a non-distributed mode (default), as a single Java process. This is useful for debugging,
                For this mode no configuration changes are required. Simply start by  following command:

   Pseudo Distributed:
Hadoop can also be run on a single-node in a pseudo-distributed mode where each Hadoop daemon(background service) runs in a 

                           separate Java process.

    Use the following:

    etc/hadoop/core-site.xml:

        <configuration>

            <property>

                <name>fs.defaultFS</name>

                <value>hdfs://localhost:9000</value>

            </property>

        </configuration>

    etc/hadoop/hdfs-site.xml:

        <configuration>

            <property>

                <name>dfs.replication</name>

                <value>1</value>

            </property>

        </configuration>

    Setup passphraseless ssh

    Now check that you can ssh to the localhost without a passphrase:

      $ ssh localhost

    If you cannot ssh to localhost without a passphrase, execute the following commands: 

      $ ssh-keygen -t dsa -P '' -f ~/.ssh/id_dsa

      $ cat ~/.ssh/id_dsa.pub >> ~/.ssh/authorized_keys # If password is prompted, may need to run - chmod 600 ~/.ssh/authorized_keys 

    Execution

    The following instructions are to run a MapReduce job locally. If you want to execute a job on YARN, see YARN on Single Node.

        Format the filesystem:

          $ bin/hdfs namenode -format

        Start NameNode daemon and DataNode daemon:

          $ sbin/start-dfs.sh

        The hadoop daemon log output is written to the $HADOOP_LOG_DIR directory (defaults to $HADOOP_HOME/logs).

        Browse the web interface for the NameNode; by default it is available at:

            NameNode - http://localhost:50070/

        Make the HDFS directories required to execute MapReduce jobs:

          $ bin/hdfs dfs -mkdir /user

          $ bin/hdfs dfs -mkdir /user/<username>

        Copy the input files into the distributed filesystem:

          $ bin/hdfs dfs -put etc/hadoop input

        Run some of the examples provided:

          $ bin/hadoop jar share/hadoop/mapreduce/hadoop-mapreduce-examples-2.6.0.jar grep input output 'dfs[a-z.]+'

        Examine the output files:

        Copy the output files from the distributed filesystem to the local filesystem and examine them:

          $ bin/hdfs dfs -get output output

          $ cat output/*

        or

        View the output files on the distributed filesystem:

          $ bin/hdfs dfs -cat output/*

        When you're done, stop the daemons with:

          $ sbin/stop-dfs.sh

    YARN on Single Node

    You can run a MapReduce job on YARN in a pseudo-distributed mode by setting a few parameters and running ResourceManager daemon and NodeManager daemon in addition.

    The following instructions assume that 1. ~ 4. steps of the above instructions are already executed.

        Configure parameters as follows:

        etc/hadoop/mapred-site.xml:

        <configuration>

            <property>

                <name>mapreduce.framework.name</name>

                <value>yarn</value>

            </property>

        </configuration>

        etc/hadoop/yarn-site.xml:

        <configuration>

            <property>

                <name>yarn.nodemanager.aux-services</name>

                <value>mapreduce_shuffle</value>

            </property>

        </configuration>

        Start ResourceManager daemon and NodeManager daemon:

          $ sbin/start-yarn.sh

        Browse the web interface for the ResourceManager; by default it is available at:

            ResourceManager - http://localhost:8088/

        Run a MapReduce job.

        When you're done, stop the daemons with:

          $ sbin/stop-yarn.sh

Problem#1:org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /my_hadoop_dir/README.md._COPYING_ could only be replicated to 0 nodes instead of minReplication (=1).  There are 1 datanode(s) running and no node(s) are excluded in this operation.

Soln: solved by increasing dfs size capacity.. hardisk contained only 450MB free disk space which was not enough for replication.

Setting up hadoop cluster(Fully Distributed Mode) on VM, (Using Virtual box 7), 

• Host - (OS - Windows 10, HW - [ RAM 16G, CPU -  Intel core i7, Storage - F drive has 500G VM is created on this drive. ] ) 

• Guest (s)- (

  1. Master node - OS - Centos 7 minimal server, HW - [ RAM 2G, CPU cores - 4, Storage - 20G Auto partitioned, Network Interface - 1 (Bridge Adapter) ] 

  2. Slave node - OS - Centos 7 minimal server, HW - [ RAM 4G, CPU cores - 4, Storage - 40G Auto partitioned, Network Interface - 1 (Bridge Adapter) ]
     )

1. Post OS setup on guest.. 

yum update -y

yum install wget telnet -y