Pacemaker, DRBD Active-Passive Cluster

Overview

Active Passive cluster consists of two nodes: active node and passive node. Active passive cluster ensures constant service of a certain application keeping redundant nodes to back up system in the event of a failure. When the active node goes down one of the backup nodes takes the responsibility and runs those services. In the process of fail over, the services are restarting on another node immediately without administration intervention.

Big Data processing with Apache Hadoop

Overview

Earlier software applications have been developed to run on single computer. Some examples are calculators, word processing packages, drawing applications etc. With the introduction of client server architecture vast amount of software systems were developed with databases. Most of web applications, business systems are built databases and concurrency, transaction handling are some new terms introduced with the architecture. Now world has moved to new computer era with concepts of high performance computing.

Apache Load balancing with HAProxy

Overview

HAProxy is an open source load balancing software run on Linux. It will divide the load which may be web page or database query requests upon slave servers from the master. Therefore usual Linux machine can be configured as a load balance without any hardware load balancing capabilities.

Useful Maven Commands

Overview

Previous post I have described some basic concepts of Apache Maven. Here I have included some useful commands need for day to day maven operations.

What is Maven

Overview

Developing a software  system doesn't means just writing codes. It may be set of code lines for simple program but when we go for large application development we have to think beyond that. When developing java applications some important tasks have to considered.