Apache Hadoop is an open source framework used for distributed storage as well as distributed processing of big data on clusters of computers which runs on commodity hardwares. Hadoop stores data in Hadoop Distributed File System (HDFS) and the processing of these data is done using MapReduce. YARN provides API for requesting and allocating resource in the Hadoop cluster.

The Apache Hadoop framework is composed of the following modules:
  • Hadoop Common
  • Hadoop Distributed File System (HDFS)
  • YARN
  • MapReduce

This article explains how to install Hadoop Version 2 on Ubuntu 18.04. We will install HDFS (Namenode and Datanode), YARN, MapReduce on the single node cluster in Pseudo Distributed Mode which is distributed simulation on a single machine. Each Hadoop daemon such as hdfs, yarn, mapreduce etc. will run as a separate/individual java process.

In this tutorial you will learn:
  • How to add users for Hadoop Environment
  • How to install and configure the Oracle JDK
  • How to configure passwordless SSH
  • How to install Hadoop and configure necessary related xml files
  • How to start the Hadoop Cluster
  • How to access NameNode and ResourceManager Web UI

Pantheon desktop is a default desktop used by the ElementaryOS Linux system. It is hand-crafted specifically for the ElementaryOS Linux distribution and the result is extremely polished, fast performing and user friendly desktop environment.

At this point the Pantheon desktop is not a part of the standard Ubuntu repository. However, it can be easily installed by enabling the official ElementaryOS PPA repository within the Ubuntu 18.04 system.

In this How to install Pantheon desktop on Ubuntu tutorial you will learn
  • How to add the ElementaryOS PPA repository.
  • How to install the Pantheon desktop on Ubuntu 18.04.

The default TTY console font size on Ubuntu 18.04 Server may be not satisfactory in many cases. However, there is a simple way to increase or even decrease the font size on Ubuntu 18.04 TTY console by re-configuration of the console font and keymap setup program console-setup .

The default TTY console resolution on Ubuntu 18.04 Server is normally 800x600. This may be satisfactory in many cases. However, there are times that higher resolution is required. To increase TTY console resolution on the Ubuntu 18.04 server it is necessary to change the configuration of the relevant GRUB boot loader settings within the /etc/default/grub.

The welcome message shown to a user upon the terminal login whether it is via remote SSH login or directly via TTY or terminal is a part of motd also known as "Message Of The Day" daemon. The motd message can by customized to fit individual needs of each user or administrator by modifying the /etc/motd file or script within the /etc/update-motd.d directory.

In this tutorial you will learn:
  • How to append additional information to motd message
  • How to modify motd message
  • How to disable selected parts of motd daemon
  • How to completely disable motd message