Editing Technical Solution Documnet for tobacco board project for NIIT

[[category:NIIT-Tobacco Board Project]]


'''Technical Solution Document'''
'''For NIIT '''

'''For Tobacco Board '''


'''Dated 28<sup>th</sup> Jan 2012'''

=='''Table of Contents'''==
= Objective  =

* To build a Solution which is highly available 
* The solution needs to be build for Apache-Tomcat application with MySQL as backend database 
* The solution needs to be deployed on Linux ( SLES – Suse Linux Enterprise Server) with HA Components
* The solution needs to be 2 node cluster on High availability in Active / Passive mode 
* No SAN or NAS based Infrastructure will be used .

= Technical Concept  =

* OS Platform – SLES , SUSE Linux Enterprise Server 
* Application Platform – Linux based Apache with Tomcat Integration for JAVA Platform
* Database Server – MYSQL 
* 2 Node Cluster on DRBD (Distributed Replicated Block Device) Replication and Heartbeat as Clustering Suite 
* DRBD will provide us Block level replication over the LAN to ensure that any write operation on the Block level on Active Node will get replicated instanatly on the passive node .
* As Data changes will be only at Mysql database level , Mysql will be implemented on DRBD block devices 
* Heartbeat will be implementated for 2 node cluster and will be integrated with DRBD.

= Hardware / Software Requirements =

* '''Hardware'''
** Cluster Ready Server hardware – eg HP Servers with ILO2/ ILO3 
** 3 High Speed Lan Cards , One for DRBD replication and 2 for Bonding 
** Lan Cable – Cross and Network Switch 
* '''Software'''
** OS – SLES 11 or the Latest
** DRBD
** Heartbeat 
** Mysql
** Apache
** Tomcat

= Architecture  =

[[Image:Niit-1.png]]

[[Image:Niit-2.png]]

= Details of Components  =
== Heartbeat  ==
Heartbeat is a daemon that provides cluster infrastructure (communication and membership) services to its clients. This allows clients to know about the presence (or disappearance!) of peer processes on other machines and to easily exchange messages with them. 

In order to be useful to users, the Heartbeat daemon needs to be combined with a cluster resource manager (CRM) which has the task of starting and stopping the services (IP addresses, web servers, etc.) that cluster will make highly available. Pacemaker is the preferred cluster resource manager for clusters based on Heartbeat. 


== DRBD ==
'''DRBD® '''refers to block devices designed as a building block to form high availability (HA) clusters. This is done by mirroring a whole block device via an assigned network.DRBD can be understood as network based raid-1. 

In the illustration below, the two orange boxes represent two servers that form an HA cluster. The boxes contain the usual components of a Linux™ kernel: file system, buffer cache, disk scheduler, disk drivers, TCP/IP stack and network interface card (NIC) driver. The black arrows illustrate the flow of data between these components. 


[[Image:Niit-3.png]]