What is a datanode in Hadoop?

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What is a datanode in Hadoop?

Postby dharama123 » Thu Sep 18, 2014 3:35 am

What is a datanode in Hadoop?


Re: What is a datanode in Hadoop?

Postby Guest » Sat Sep 20, 2014 5:41 pm

Unlike Namenode, a datanode actually stores data within the Hadoop distributed file system. Datanodes run on their own Java virtual machine.

A DataNode stores data in the [HadoopFileSystem]. A functional filesystem has more than one DataNode, with data replicated across them.

On startup, a DataNode connects to the NameNode; spinning until that service comes up. It then responds to requests from the NameNode for filesystem operations.

Client applications can talk directly to a DataNode, once the NameNode has provided the location of the data.

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