cloudera 0.18 -> 0.20

• hadoop install

  $ sudo su -
  # apt-get install hadoop-0.18 hadoop-0.18-namenode  hadoop-conf-pseudo
  # apt-get install hadoop-0.18-datanode hadoop-0.18-jobtracker hadoop-0.18-tasktracker
  

• hadoop namenode format

  # su -s /bin/bash - hadoop -c 'hadoop namenode -format'
  

  • use instruction

    # su -s /bin/bash - hadoop -c " COMMAND "
    

• startup

  # /etc/init.d/hadoop-namenode start
  

• setup the conf files

...

(hadoop-env.sh, core-site.xml, hdfs-site.xml, mapred-site.xml)

....

• upgrade cloudera-hadoop-0.18 ---> official-hadoop 0.20

  # su -s /bin/bash - hadoop -c " /opt/hadoop/bin/hadoop namenode -upgrade "
  

• the successful screen shot :

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• but terminal console is handle by hadoop process

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• Right now, our NameNode is in SAFE mode waiting for the DataNodes? to connect.

• Start the rest of HDFS

When the datanodes start, they will connect to the Name Node and an upgrade will be initiated.

# su -s /bin/bash - hadoop -c "/opt/hadoop/bin/hadoop-daemon.sh start namenode -upgrade"

Once all the DataNodes? have upgraded, you should see a message that Safe mode will be turned off automatically in X seconds.

• start MapReduce

After you have verified correct operation of HDFS, you are ready to start MapReduce.

• finalize the hdfs upgrade

Now that you've confirmed your cluster is successfully running on Hadoop 0.20, you can go ahead and finalize the HDFS upgrade: {{{{ $ sudo -u hadoop hadoop dfsadmin -finalizeUpgrade }}}