Org.apache.hadoop.ipc.Client:Retrying connect to Server exception resolution

Check that Datanode is not connected to Namenode.

Check whether the configuration of each node in etc/hosts has 127.0.1.1 xxxxxx. If you have to block it or remove it, restart each node.

Cause: 127.0.1.1 is a local loopback in Debian. This causes problems with Hadoop parsing. This setting should be left when you do a pseudo-distributed Hadoop cluster.

If the same problem occurs in the same way as above, or if the Etc/hosts directory does not have 127.0.1.1 settings.

You can add the following to the Conf/core-site.xml (0.19.2 version of Conf/hadoop-site.xml)

<property>       <name>hadoop.tmp.dir</name>       <value>/var/log/hadoop/tmp</value >       <description>a Base for other temporary directories</description>  </property>

After you restart Hadoop, reformat the namenode.

The reason is: Hadoop default configuration is to put some TMP files in the/tmp directory, after rebooting the system, the TMP directory is cleared, so error

Org.apache.hadoop.ipc.Client:Retrying connect to Server exception resolution