When a failure occurs, modern IT systems often have a "failover" feature that provides the capability to switch over to another set of servers so that users can continue to use the application. There are 2 primary types of failover, hot and cold. A hot failover immediately detects a failure and switches over to a secondary running system. There’s usually no interruption visible to the operator. A cold failover is a manual, and therefore, delayed switch-over to a secondary system. The delay occurs because the secondary system needs to be brought online and consequently, some data can be lost. So what’s the right choice for my operation?
A hot failover is designed to detect a failure and immediately switch over to a secondary running system: the end-user of the application will see little or no interruption of performance when the switch occurs. This is the most resource-intensive mode, as it involves duplication of infrastructure and for data to be available in multiple locations simultaneously.
In a cold failover when a failure is detected there is a manual and delayed switch-over to a secondary system because this system needs to be started and brought online. Some data is inevitably lost in the time it takes to “spin-up” these cold systems. This type of configuration is far less resource-intensive than a hot configuration but it does leave potential information gaps and these can be critically important in a security event.
That’s why most organizations choose systems that support hot failover configuration. There are a number of ways that platforms support hot failover, at SureView we use the UL 1981 alarm monitoring standard, as this is a rigorous certification that addresses hot failover when processing physical security alarms. There are other IT standards around hot failover, so consult with your IT team to make sure your security response software meets these requirements.