scalability-knowledge
Installation
SKILL.md
Scalability Knowledge Base
Quick reference for scalability patterns, stateless design, PHP-FPM tuning, and capacity planning in PHP applications.
Vertical vs Horizontal Scaling
| Aspect | Vertical (Scale Up) | Horizontal (Scale Out) |
|---|---|---|
| Approach | Bigger server (CPU, RAM) | More servers |
| Cost curve | Exponential (diminishing returns) | Linear (commodity hardware) |
| Downtime | Often required for upgrade | Zero-downtime rolling deploys |
| Limit | Hardware ceiling | Theoretically unlimited |
| Complexity | Low (single server) | High (distributed system) |
| Data consistency | Simple (single node) | Requires distributed coordination |
| Failure blast radius | Entire application | Single instance |
| PHP suitability | Quick win, limited ceiling | Natural fit (shared-nothing) |