With high load and many integrations, it is important not only to scale, but also to prevent overloads and avalanche-like failures.
- Throttling - controls the frequency of requests in real time, Circuit Breaker - breaks the call chain when failures in dependent services.
They protect the API from falling, increase the fault tolerance of the system and help maintain stable operation even in case of partial failures.
What is throttling
| Characteristic | Description |
|---|---|
| Frequency limitation | Control the number of requests in a given time interval (RPS, RPM) |
| Flexible tuning | Endpoint, key, user, or IP limits |
| Smooth release | Load reduction without full interlock |
What is circuit breaker
| Function | What does |
|---|---|
| Error monitoring | Monitors the frequency of errors/timeouts in the API or external service |
| Call disconnection | Temporarily blocks calls when the failure threshold is reached |
| Automatic recovery | Checking Availability and Enabling Calls During Stabilization |
How we implement
Using libraries (e.g. Resilience4j, Hystrix, Envoy, Kong)
Configuring gateway limits and backend logic
Event logging and failure/recovery metrics
Circuit breaker notifications and dramatically reduced bandwidth
Integration with Prometheus, Datadog, Grafana for monitoring
Advantages
Protection against "collapse" of the system in case of failures depending on
Stability under load and during incidents
Isolate problematic components and improve API reliability
Simplified debugging and quick response to anomalies
Avoid cascading failures in microservice architecture
Where especially important
APIs interacting with payment gateways and external banks
Multi-dependency microservice architectures
Applications with millions of users and high resource competition
Delay-sensitive realtime platforms
Throttling and circuit breaker are strategic survival mechanisms of the API. We will implement protection that will allow your service to remain stable, fast and predictable even in the most unstable conditions.