If Redis goes down, what technique helps prevent overwhelming the database?

If Redis goes down, what technique helps prevent overwhelming the database?

• A. Permanently disable caching.
• B. Circuit breakers.
• C. Increase TTL for all keys.
• D. Move the cache to a slower disk.

Answer: (B)

Circuit breakers prevent cascading failures by stopping calls to a failing service, so a Redis outage won’t drive a flood of requests to the database. When Redis is unhealthy, the circuit breaker trips and blocks further cache calls, letting the system fail fast or switch to a safe fallback. This containment keeps the database from being overwhelmed during cache outages. Other options don’t address this containment. Permanently disabling caching removes the performance and resilience benefits of the cache. Increasing TTL doesn’t help when Redis is down and can lead to stale data or wasted cache memory. Moving the cache to slower storage reduces speed, not protection, and can actually worsen load and latency.

Circuit breakers prevent cascading failures by stopping calls to a failing service, so a Redis outage won’t drive a flood of requests to the database. When Redis is unhealthy, the circuit breaker trips and blocks further cache calls, letting the system fail fast or switch to a safe fallback. This containment keeps the database from being overwhelmed during cache outages.

Other options don’t address this containment. Permanently disabling caching removes the performance and resilience benefits of the cache. Increasing TTL doesn’t help when Redis is down and can lead to stale data or wasted cache memory. Moving the cache to slower storage reduces speed, not protection, and can actually worsen load and latency.