This guide is a collection or a summary on how to install and use a footprint of Apache Hadoop. I tried to follow an old version 2.7.1 guide that I created few years ago and adjusted this to use the latest version. Apache Hadoop 3.5.0 is used below; check the Apache releases page before future installations. These instructions target Linux (Ubuntu/Debian) for development or testing. Production clusters need Kerberos, network controls, encryption, monitoring, backups, and an upgrade plan....