Introduction Hadoop is a open source software use for distribute computing. It is reliable, scalable and perfectly use for big data purpose. Hadoop cluster commonly consist of NameNode, secondary NameNode, resource manager and DataNode. NameNode itself store block metadata on the file call fsimage. Secondary NameNode is a NameNode helper. It log changes to fsimage (checkpoint) but do not store the actual fsimage file. Secondary NameNode update frequently and update NameNode fsimage by combining update logs with fsimage to achieve most recent fsimage.
Background if you have number of files need version control, you may heard about what is Git able to provide. Git is a mature version control system widely use by many peoples around the world. Storing repository online can be achieve using GitHub. There are free version for public repositories and pay version for private repositories. Other option is using Amazon AWS with local git. Amazon simple storage service (S3) is a online storage service that provide storage for your data and can be access from anywhere as long you have internet access.
Introduction MySQL is a free database commonly install on many Virtual Private Server (VPS). It is a powerful database with many community support. MySQL is a popular open source relational database, it is use SQL language to operate. Many MySQL installation power up Linux base web site to operate. Prerequisites We are going to install MySQL database in Linux machine particularly Ubuntu. in this tutorial I will show you how to install MySQL on Ubuntu version 14.
Introduction The continuity operation of database service is very important for website to minimize down time and better user experience. Database replication is one of technique use by many administrator to save maintain one database while other still in operation to service every query to website. Database replication is offer a mirror on one database to others within one or different server or different data center location. Every record on database one is replicated exactly on database two, three an so on.
Introduction Apache is the most popular web server applications. It is an open source software and readily available at no cost. It operates on over fifty percent of all live internet sites around the globe. It is fast, dependable, safe, powerful and adjustable. Apache architecture allow you to splits its operation and resources into specific pieces that could be personalized and tweaked on their own. These scenarios are relating to a number of sites running on one server, process by name or Internet protocol address of virtual hosts.
There are number of legitimate reason to modify SSH port of Linux server. The benefit to non default port is to safeguard again port scanner applications which are keep searching for particular service (SSH or others). It will not likely take care of hacking issue completely but delay password brute force at the very least . Change SSH post on Debian Linux To change port on Debian Linux follow following instruction : Login to Debian Linux with SSH program or putty.
Cron job is a system daemon employed to undertake chosen jobs run in the background. Scheduled cron job is a very helpful tool for system administrator to carry out number of job automatically. Before setting cron job, you need to install cron. Install Cron on Debian linux Login to linux machine run debian. Execute following command to install cron. sudo apt-get update sudo apt-get install cron After cron is successfully installed, You should able to setup task.
Apache is a openly available Web server operates on most UNIX-based operating systems. It makes up about over half of all working websites on the internet. The web server alone is flexible, fast, reliable, and secure. You can easily run multiple virtual site on Apache. You can add or remove it anytime you want. We will discussing about removing virtual site from Apache on this guide. Methods to setup a new virtual site will be on other post.