Hadoop provides web interfaces for each of its services. The namenode UI or the namenode web interface is used to monitor the status of the namenode and can be accessed using the following URL:
http://<namenode-server>:50070/
The namenode UI has the following sections:
Overview: The general information section provides basic information of the namenode with options to browse the filesystem and the namenode logs.
The following is the screenshot of the Overview section of the namenode UI:
The Cluster ID parameter displays the identification number of the cluster. This number is same across all the nodes within the cluster.
A block pool is a set of blocks that belong to a single namespace. The Block Pool Id parameter is used to segregate the block pools in case there are multiple namespaces configured when using HDFS federation. In HDFS federation, multiple namenodes are configured to scale the name service horizontally. These namenodes are configured to share...