2. Upgrade Hadoop

  1. On all nodes:

    • For RHEL/CentOS:

      yum upgrade hadoop\*

    • For SLES:

      zypper update hadoop\*

  2. Start HDFS.

    1. Start NameNode. On the NameNode host machine, execute the following command:

      sudo su -l hdfs -c "/usr/lib/hadoop/bin/hadoop-daemon.sh start namenode"
                             

    2. Start Secondary NameNode. On the Secondary NameNode host machine, execute the following command:

      sudo su -l hdfs -c "/usr/lib/hadoop/bin/hadoop-daemon.sh start secondarynamenode"
                             

    3. Start DataNodes. On all the DataNodes, execute the following command:

      sudo su -l hdfs -c \"/usr/lib/hadoop/bin/hadoop-daemon.sh start datanode\"
                             

    4. Execute the following on the NameNode machine:

      hadoop dfsadmin -safemode wait

  3. Start MapReduce.

    1. Start JobTracker. On the JobTracker host machine, execute the following command:

      sudo su -l mapred -c "/usr/lib/hadoop/bin/hadoop-daemon.sh start jobtracker"
                         

    2. Start JobHistory Server. On the JobHistory Server host machine, execute the following command:

      sudo su -l mapred -c "/usr/lib/hadoop/bin/hadoop-daemon.sh start historyserver"
                         

    3. Start all TaskTrackers. On all the TaskTrackers, execute the following command:

      sudo su -l mapred -c \"/usr/lib/hadoop/bin/hadoop-daemon.sh start tasktracker\"
                         


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