Failover

Failover from a Technical Perspective

For many businesses and government agencies today, a complete system failure is considered a high-impact disaster, so IT departments or contracted partners are turning to solid preparations and updated technology to ensure that during times of crisis, systems appear to continue to be operational, even if there are immediate failures in a data center environment.

Traditionally, a computer server breakdown used to mean widespread panic and a scramble to find backup tapes and a spare server to restore information. Inevitably, this meant the operations of the business would be interrupted, people would become frustrated over not having access, and even a loss of data could occur. Recovering from a backup could take hours; even planned maintenance can take the server down during business hours, leaving teams unable to work. But with more advanced technology available, moving from one system to another has become reasonably automatic, and in cases where an entire data center failure occurs, a redundant data center is ready to ensure that interruptions are very minimal in nature or not even detectable to the average system user at an organization.

Some ways of providing technical failover are either with a fault-tolerant machine with duplicate hardware or with a high-availability (HA) architecture. The duplicate hardware in a redundant architecture works as a “copy” of the main system, so in the event that the main system does fail, the redundant machine takes over and becomes primary until repairs are made to the primary server. Some larger corporations, or ones that host extremely sensitive data, have sought additional layers of security and assurance that a system failure will not stop operational capability, and this is where the HA architecture comes into play. HA works by linking several machines together so that the failure of one computer brings another online—the users see no difference. The applications run on the servers, but the data are stored on the network, thus adding more protection to the environment. When any single server fails, users are redirected to other servers while the failed server is repaired or replaced and brought back online. In any event, a technical failover, from single system failure to complete data center shutdowns, can take place with minimal impact.

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