Jatkuvikäyttökyky

Jatkuvikäyttökyky, or continuous availability, is a concept referring to the ability of a system or service to remain operational and accessible without significant interruption. It is a critical characteristic for many applications, particularly those where downtime can lead to substantial financial losses, reputational damage, or disruption of essential services.

Achieving continuous availability involves a combination of strategies and technologies. These include redundancy at various levels, such as redundant hardware components, power supplies, and network connections. Fault tolerance is another key aspect, meaning the system is designed to continue operating even when individual components fail. This can be achieved through techniques like clustering, where multiple servers work together and can take over if one fails.

Disaster recovery planning and business continuity are closely related to continuous availability. These focus on preparing for and responding to major disruptions, such as natural disasters or cyberattacks, to minimize downtime and data loss. Regular testing of these plans is crucial to ensure their effectiveness.

The specific requirements for continuous availability vary depending on the application. For some, a few minutes of downtime might be acceptable, while for others, such as critical financial trading systems or emergency services, even a few seconds of unavailability can be catastrophic. Therefore, the level of investment in continuous availability measures is often directly proportional to the cost of downtime.