Redundancy And Replication - rFronteddu/general_wiki GitHub Wiki

Redundancy is the duplication of critical components or functions of a system with the intention of increasing the reliability of the system, usually in the form of a backup ro fail-safe, or to improve the actual system performance.

Redundancy plays a key role in removing the single points of failure in the system and provides backups if needed in a crisis.

Replication means sharing information to ensure consistency between redundant resources, such as software or hardware components, to improve reliability, fault-tolerance, or accessibility.

Replication is widely used in DBMS usually with a master-slave relationship between the original and the copies. The master gets all the updates, which then ripple through to the slaves. Each slave outputs a message stating that it has received the update successfully, thus allowing the sending of subsequent updates.