How to install and configure a Hadoop cluster

Setting up and configuring a Hadoop cluster requires following these steps:

1. Download the Hadoop installation package: First, you need to download the latest version of the Hadoop installation package from the official Hadoop website (https://hadoop.apache.org/), and then unzip it to a specified directory after completion.
2. Set up Hadoop environment variables: configure the environment variables for Hadoop, including JAVA_HOME, HADOOP_HOME, and add the bin directory of Hadoop to the system’s PATH environment variable.
3. Setting up a Hadoop cluster involves editing configuration files such as core-site.xml, hdfs-site.xml, mapred-site.xml, and yarn-site.xml to specify the IP addresses, port numbers, and data storage paths of each node in the cluster.
4. Set up passwordless SSH login: Configure passwordless SSH login between nodes in the cluster to ensure they can communicate with each other.
5. Start the Hadoop cluster by running the start-dfs.sh command on the namenode node to start the HDFS service, and running the start-yarn.sh command on the resourcemanager node to start the YARN service.
6. Verify the cluster running status by accessing Hadoop’s web pages (http://namenode:50070 and http://resourcemanager:8088) through a browser.

By following the steps above, you can successfully install and configure a Hadoop cluster. It is important to carefully check the parameters in the configuration files during the setup process to ensure proper communication between nodes.