Systems must handle not only normal traffic but also abusive, automated or malicious patterns. Rate limiting, throttling and DDoS protections affect how systems behave under extreme load and must be considered in performance tests.
Rate Limiting and Throttling Behaviour
Rate limiting and throttling protect backends by slowing or blocking excessive requests from clients or IP addresses. Performance tests should verify that limits are enforced correctly and that legitimate users still receive acceptable service when abusive traffic is present.
Example rate limiting behaviours to test:
- Per-user or per-IP request limits per minute
- Burst limits vs sustained limits
- Error responses or headers when limits are exceeded
- Behaviour when multiple endpoints share the same underlying quotaDDoS and Abuse Considerations
While full-scale DDoS simulations are rare, you can model partial abuse scenarios (for example sudden spikes from a subset of clients) to see how WAFs, CDNs or rate limiters respond. Logs and metrics should make it easy to distinguish malicious-looking patterns from legitimate surges.
Including these scenarios in your planning ensures that protections work as intended without surprising side effects.
Common Mistakes
Mistake 1 — Ignoring protection mechanisms in performance design
This leads to blind spots.
❌ Wrong: Assuming that only backend capacity matters.
✅ Correct: Account for WAFs, proxies and rate limiters in scenarios.
Mistake 2 — Overly aggressive limits that block real users
This hurts usability.
❌ Wrong: Limits too low or poorly tuned.
✅ Correct: Use analytics and tests to set thresholds that balance protection and user experience.