Hadoop 9870

Port 9870 in Hadoop typically refers to the HTTP user interface (UI) of the Hadoop NameNode service. The NameNode is a critical component in Hadoop’s Hadoop Distributed File System (HDFS), responsible for storing metadata and namespace information about files and directories in the HDFS cluster. The NameNode’s web UI is available on port 9870 by default and provides important information and tools for managing the HDFS cluster. Here’s what you can typically find on port 9870:

1. HDFS Cluster Overview: The Hadoop NameNode web UI on port 9870 provides an overview of the HDFS cluster’s health and status. You can see information about the number of DataNodes, the total capacity of the cluster, the number of live and dead DataNodes, and the amount of used and available storage.

2. File System Browser: You can use the web UI to browse the HDFS file system. It allows you to navigate through directories, view file properties, and check the replication factor of files.

3. DataNode Status: The web UI also provides information about each DataNode in the cluster, including its hostname, storage capacity, and health status. This helps administrators monitor the health of individual DataNodes.

4. Hadoop Logs: You can access various log files, including the NameNode logs and DataNode logs, to troubleshoot issues or monitor the cluster’s performance.

5. Utilities: Some Hadoop distributions provide additional utilities or options in the NameNode web UI, such as the ability to trigger block scanning or cluster rebalancing.

The NameNode’s web UI on port 9870 is a valuable tool for Hadoop administrators and developers for monitoring and managing the HDFS cluster. It allows you to check the cluster’s health, troubleshoot problems, and perform various administrative tasks related to Hadoop’s distributed file system.