What does 'brittleness' refer to in system design?

In system design, 'brittleness' specifically refers to the inability of a system to degrade gracefully under stress. This means that when a system faces high loads, unexpected inputs, or other stressful conditions, a brittle system fails in a way that can be disruptive or catastrophic rather than managing the failure in a controlled manner. A brittle system can exhibit symptoms such as crashes, loss of functionality, or a complete outage when faced with issues, rather than providing a reduced level of service or maintaining core functionality.

The concept of brittleness contrasts with resilience, which involves systems that can handle stress and continue to operate, albeit at a lower capacity or functionality, during adverse conditions. In well-designed systems, instead of failing completely, components may fail gracefully, allowing others to continue functioning or the overall service to remain available in a limited manner.

The other choices address different aspects of system design. Recovery from failures relates more to resilience and redundancy, scaling effectively refers to the system's capability to expand resources according to demand, and automated system updates focus on maintenance and operational efficiency rather than the inherent nature of the system to withstand or manage stress.