It’s a fact; there is nothing perfect under the sun. Even if the architecture of your network is outstanding and robust, there will always be the occasional unexpected event to deal with. The cause may be either internal or external. Whether the problem is an application failure, a power supply failure, a hardware failure, or even a network system failure, it doesn’t matter. There is always the possibility of an unexpected event causing a failure. Whatever the cause of the problem, the important thing is that there are ways to keep your business up and running. A business which is shut down because of a server failure is a business in serious trouble. That is why there is a vital need for server failover options.
There are a number of different server failover solutions on the market. The best of the bunch offer automatic failover and switchback, although single click failover may be acceptable in some situations. Some automated solutions monitor your network, attempt to identify problems before they become critical and — if possible — provide an automated work-around or remedy. If these automated solutions are unable to fix the problem completely, they can at least address the issue by ensuring that the best suited standby server is available to take up the slack. The standby server will either be located on premise, or it may be located off-site as the remove disaster recovery server.
There are many events which require server failover. In a lot of cases this is actually a planned event, as with maintenance to power lines by the electric company. Most of the time, unfortunately, the electric company does not do a very good job of making certain that business are aware of an impending scheduled power outage, even when a reliable power supply is mission critical to performance of business activities. Other common events that require server failover are natural disasters. This need not be a weather event of epic proportions. Isolated severe thunderstorms, snow and ice events, and periods of high wind can just as easily cause power outage.
Many times, there is little to no warning that there is an approaching event which threatens to shut down your business. Server failover may be the only thing which prevents serious problems from sidelining your business. If you are lucky, you will be aware of the approaching event, and can manually fail over ahead of time to avoid problems ahead of time.
The other side of server failover that often receives less attention than it deserves, is what happens after the problem causing event is resolved and the situation returns to normal. At that point, it is vital that switchback goes smoothly and does not result in additional problems. Whatever server failover solution a company decides upon, it should be one that ensures a controlled switchback takes place in a manner that ensures proper database re-synchronization takes place.