Technology Fundamentals
Redundancy
Definition
In engineering, redundancy is the duplication of critical components or functions of a system with the intention of increasing reliability of the system, usually in the form of a backup or fail-safe.
Why It Matters
Redundancy is a key principle for building fault-tolerant and highly available systems. It ensures that if one component fails, another one can take its place, preventing downtime.
Contextual Example
A critical database is often set up with a redundant "failover" server. If the primary database server crashes, the system automatically switches to the backup server, so the application continues to function without interruption.
Common Misunderstandings
- Redundancy adds cost and complexity but is essential for systems that cannot afford to fail.
- It can apply to hardware (like redundant power supplies or hard drives in a RAID array) and software (like running multiple instances of a service).