A well-designed capacity plan forms the foundation for system stability. Performance stress testing, capacity planning, and elastic scaling are three essential components of capacity design. These components are critical for maintaining stable business operations, enhancing user experience, and optimizing costs. Performance stress testing provides reference data for capacity planning to determine the resource scale and configuration needed for stable system operation. Elastic scaling automatically adjusts resource scale and configuration based on actual load conditions during operation, balancing system performance with cost-effectiveness.