Rate Limiting, Counters, Throttling, and API Protection
Protect applications and APIs using Redis for request counting, throttling, and lightweight abuse control.
Inside this chapter
- Why Rate Limiting Matters
- Counters in Redis
- Windowing Strategies
- More Than Just APIs
- Business Example
Series navigation
Study the chapters in order for the clearest path from Redis basics to advanced cache architecture, operations, and distributed-system design. Use the navigation at the bottom to move smoothly through the full tutorial series.
Why Rate Limiting Matters
APIs and login endpoints can be abused through rapid repeated calls, bots, or accidental client loops. Rate limiting protects system stability, improves fairness, and reduces abuse risk.
Counters in Redis
INCR api:client:42:requests
EXPIRE api:client:42:requests 60This pattern lets an application track how many requests a client has made in a time window.
Windowing Strategies
Simple fixed-window counters are easy to implement, while sliding-window or token-bucket strategies may behave more smoothly. The right choice depends on business rules and abuse patterns.
More Than Just APIs
Redis-backed counters can also protect login attempts, OTP generation frequency, report generation, SMS sends, and any other event where per-user or per-client throttling matters.
Business Example
A public API may allow 100 requests per minute per client token. Redis counters and expirations can enforce that efficiently across multiple application instances.