Redundancy and Continuity
Redundancy is a system design in which a component is duplicated so if it fails there will be a backup.
Continuity is the unbroken and consistent existence or operation of something over a period of time:
Although these concepts seem to be similar, their application in information technology that draws clear differences. Redundancy relates to the design of a solution and its ability to remain operational in the event of a single loss, or single point of failure. A good design will address the following:
- Duplication or replication of core functions
- Geographic separation
- Automated activation
- Multiple forms of connectivity consist of
- Different suppliers
- Different media
- Different access methods
Continuity in technology adopts a more general view related to operational continuity versus solution continuity. It is a given that operations can be stabilized with redundancy, however a 100% up time is not. In those situations continuity takes over and addresses the following:
- What is the plan when operations of a system go offline
- How long can an outage be tolerated
- What is the cost of an outage
- What are the priority operational components in the system
- Are continuity rates clearly communicated with proper expectations
