How would you solve the problem when your service starts calling another service too frequently and it crashes?

If a service calls another service too frequently and the latter starts to fail, protective mechanisms should be implemented to prevent overload:

1. Circuit Breaker implementation — when a certain number of errors or timeouts occur, further requests are temporarily blocked, giving the service time to recover.

2. Rate limiting — limit the number of requests per unit of time to avoid overwhelming the external service.

3. Retry with exponential backoff — retry requests with increasing intervals after errors to reduce load.

4. Caching results — if possible, store responses and reuse them to reduce the number of calls.

Example of using Circuit Breaker with the Resilience4j library in Java:

CircuitBreaker circuitBreaker = CircuitBreaker.ofDefaults("externalService");
Supplier<String> decoratedSupplier = CircuitBreaker
    .decorateSupplier(circuitBreaker, () -> callExternalService());

Try<String> result = Try.ofSupplier(decoratedSupplier)
    .recover(throwable -> "Fallback response");

System.out.println(result.get());

This approach helps protect the service from failures and improves system resilience.