Recall & Review
beginner
What is the main purpose of a circuit breaker in system design?
A circuit breaker helps prevent a system from repeatedly trying to perform an operation that is likely to fail, protecting resources and allowing the system to recover gracefully.
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intermediate
How does Resilience4j implement the circuit breaker pattern?
Resilience4j provides a lightweight, easy-to-use circuit breaker that monitors failures and controls calls to external services by opening, closing, or half-opening the circuit based on failure rates and timeouts.
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beginner
What are the three states of a circuit breaker in Resilience4j?
Closed (normal operation), Open (calls are blocked), and Half-Open (test calls allowed to check if service has recovered).
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intermediate
In Resilience4j, what happens when the failure rate exceeds the threshold configured in the circuit breaker?
The circuit breaker transitions from Closed to Open state, blocking further calls to the failing service for a configured wait duration.
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intermediate
Why is the Half-Open state important in a circuit breaker?
It allows the system to test if the external service has recovered by allowing a limited number of calls before fully closing the circuit again.
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What state does a circuit breaker enter when it detects too many failures?
✗ Incorrect
When failures exceed the threshold, the circuit breaker opens to stop calls to the failing service.
Which Resilience4j feature allows you to automatically retry calls after a failure?
✗ Incorrect
The Retry feature in Resilience4j automatically retries failed calls based on configuration.
In Resilience4j, what does the Half-Open state do?
✗ Incorrect
Half-Open state allows a limited number of calls to test if the service has recovered.
Which metric does Resilience4j use to decide when to open the circuit breaker?
✗ Incorrect
Resilience4j opens the circuit breaker when the failure rate exceeds a configured threshold.
What is the benefit of using a circuit breaker in microservices?
✗ Incorrect
Circuit breakers prevent cascading failures by stopping calls to failing services.
Explain how a circuit breaker works in Resilience4j and why it is useful in a microservices architecture.
Think about how it protects your system from repeated failures.
You got /5 concepts.
Describe the configuration options you can set for a Resilience4j circuit breaker and their impact on system behavior.
Consider how these settings control when and how the circuit breaker opens or closes.
You got /5 concepts.