Background Single Point of Failure (SPOF) in HDFS: Each cluster had a single NameNode, and if that machine or process became unavailable, the cluster as a whole would be unavailable until the NameNode was either restarted or brought up on a separate machine. Ecosystem Dependency: The Hadoop ecosystem components like […]
Month: July 2014
YARN Introduction
YARN is a sub-project of Hadoop introduced in Hadoop 2.0. It is the next generation framework for resource management. With Map-Reduce focusing only on batch processing, YARN was conceptualised to provide a more general processing platform for data stored in HDFS. This document summarises the growing need of big data […]
Testing Principles
Performing Testing has always been a crucial and challenging task. Thus, to perform testing effectively and efficiently, various guild lines have been presented and suggested by scholars already in the field. Numerous testing principles have been accumulated over the period of last few decades by rigorous understanding of the testing […]
Ubuntu Firewall
Turn on the firewall ufw enable Turn off the firewall ufw disable Allow all connection by default ufw default allow Deny all connection by default ufw default deny Current status and rule ufw status Allow traffic on port ufw allow port Deny port ufw deny port Block ip address ufw […]
Install My-Sql in Ubuntu
Install sudo apt-get install mysql-server mysql-client Set root user password for localhost sudo mysqladmin -u root -h localhost password ‘urpassword’ Set root user password for anyhost: sudo mysqladmin -u root -h hostname password ‘urpassword’ Open mysql shell mysql -u root -p Allow hosts(machines) to access mysql installed on other machine(login […]
Configure Static IP Address in Ubuntu
You can configure a network adapter of a machine to use a static IP address. To configure static IP address in Ubuntu, you need to edit the /etc/network/interfaces file Open the file with Sudo Option sudo nano /etc/network/interfaces Assuming that the eth1 is the adapter for which static IP address is to be […]
Selenium Assert Statements
This blog explains the usage of assert statements in Selenium. assertTrue() in Selenium WebDriver and its implementation in WebDriver scripts. Being a Automation tester/Engineer, the word assert has become an integral part of our testing routines/activities. In literal terms, the word can be interpreted as “to state to be true” […]
Install Java in Linux
To install Java in Linux, refer the following instructions: 1. Download the 32bit or 64bit compressed binary “.tar.gz” file from here. 2. Create a system directory like /usr/lib/jvm to install JDK and copy the tar file to the directory. sudo mkdir -p /usr/lib/jvm sudo mv jdk-7u3-linux-x64.tar.gz /usr/lib/jvm/ 3. Change the present […]