System and Technology
High availability
High availability describes the design of an IT system so that it remains usable with as little interruption as possible, even when faults occur. This is achieved by providing redundant critical components, setting up automatic failover and organising maintenance work to minimise downtime. The aim is to maintain the agreed level of availability over a defined period and to avoid data loss, with acceptable downtime and recovery time defined in advance. In practice, high availability can be achieved by running applications across multiple locations in a cloud, using redundant hardware in a data centre and keeping regular backups available for recovery.
