Copy Data Using the hdfs:// Protocol

Describes the procedure to copy data from a HDFS cluster to a HPE Ezmeral Data Fabric cluster using the hdfs:// protocol.

Before you can copy data from an HDFS cluster to a HPE Ezmeral Data Fabric cluster using the hdfs:// protocol, you must configure the HPE Ezmeral Data Fabric cluster to access the HDFS cluster. To do this, complete the steps listed in Configuring a HPE Ezmeral Data Fabric Cluster to Access an HDFS Cluster for the security scenario that best describes your HDFS and HPE Ezmeral Data Fabric clusters, and then complete the steps listed under Verifying Access to an HDFS Cluster.

You also need the following information:
  • <NameNode> - the IP address or hostname of the NameNode in the HDFS cluster
  • <NameNode Port> - the port for connecting to the NameNode in the HDFS cluster
  • <HDFS path> - the path to the HDFS directory from which you plan to copy data
  • <Data Fabric File system path> - the path in the HPE Ezmeral Data Fabric cluster to which you plan to copy HDFS data
  • <file> - a file in the HDFS path

To copy data from HDFS to HPE Ezmeral Data Fabric file system using the hdfs:// protocol, complete the following steps:

  1. Run the following Hadoop command to determine if the HPE Ezmeral Data Fabric cluster can read the contents of a file in a specified directory on the HDFS cluster: 
    hadoop fs -cat <NameNode>:<NameNode port>/<HDFS path>/<file>
    Example
    hadoop fs -cat hdfs://nn1:8020/user/sara/contents.xml
  2. If the HPE Ezmeral Data Fabric cluster can read the contents of the file, run the distcp command to copy the data from the HDFS cluster to the HPE Ezmeral Data Fabric cluster: 
    hadoop distcp hdfs://<NameNode>:<NameNode Port>/<HDFS path> maprfs://<Data Fabric File system path>
    Example
    hadoop distcp hdfs://nn1:8020/user/sara maprfs:///user/sara