Why Hadoop Datanode doesn't work

The various components of Hadoop are working correctly when the Hadoop environment is built successfully. After rebooting several times Hadoop found Datanode not working properly, open the background of Hadoop http://localhost:50030 and http://localhost:50070 found lives nodes is 0.

To view log information for startup Datanode:

Org.apache.hadoop.ipc.Client:Retryingconnect to server:uec-fe/16.157.63.10:9000. Already tried 0 time (s).

To view log information for startup Namenode:

Java.io.IOException:File Xxxxxxxxx/jobtracker.info could is replicated to 0 nodes, instead of 1

The Hadoop.tmp.dir properties are also configured in Core-site.xml in the view:

<property>

<name>hadoop.tmp.dir</name>

<value>/home/hadoop/tmp</value>

<description>a base for other temporary directories.</description>

</property>

After the internet search tried a lot of ways is no use, and later read an article is not the issue of authority

sudo chown-r hadoop/home/hadoop/tmp

Then stop the Hadoop service and reformat (the general format will remind you to reformat the directory, show that it exists, delete the deleted directory, and then format it), and finally start the Hadoop service.

Summary：

Solutions to this type of problem:

1> Configuration Hadoop.tmp.dir Properties;

2> Modify Permissions sudo chown-r hadoop/home/hadoop/tmp (hadoop.tmp.dir value)

Finally, there may be other reasons why Hadoop Datanode cannot work and is accumulating.