DataNode

Post date: Feb 08, 2019 9:38:27 AM

It is also known as Slave. HDFS Datanode is responsible for storing actual data in HDFS. Datanode performs read and write operation as per the request of the client

• 1. DataNode is responsible for storing the actual data in HDFS.

  2. DataNode is also known as the Slave

  3. NameNode and DataNode are in constant communication.

  4. When a DataNode starts up it announce itself to the NameNode along with the list of blocks it is responsible for.

  5. When a DataNode is down, it does not affect the availability of data or the cluster. NameNode will arrange for replication for the blocks managed by the DataNode that is not available.

  6. DataNode is usually configured with a lot of hard disk space. Because the actual data is stored in the DataNode.

Name Node Configuration

    Processors: 2 Quad Core CPUs running @ 2 GHz

    RAM: 128 GB

    Disk: 6 x 1TB SATA

    Network: 10 Gigabit Ethernet