High availability computing is a mechanism to implement a computing platform to make sure that the data and application are available in normal network and power outage scenarios. To make this happen, the system is replicated into two or more identical installation, probably at different geographical regions. It also involves redundancy of networks and power systems. Apart from that, another major technique is server replication and clustering within a site or between two distant sites so that the system continues to perform with automatic switchover from one unit to another in the event of unavailability of the first node. Simply put, high availability computing technique tries to ensure that the services and data are available in normally disruptive situations such as power outages, network disconnections or other disaster.