Which technique helps prevent a cache stampede by preloading the cache before expiry?

Which technique helps prevent a cache stampede by preloading the cache before expiry?

• A. Proactive cache warming.
• B. TTL reconfiguration.
• C. LRU adjustment.
• D. Cache invalidation on write.

Answer: (A)

The idea being tested is proactive cache warming. This approach prevents a cache stampede by preloading data into the cache before it expires, so when demand spikes occur, requests are served from the cache rather than forcing a burst of backend load. In practice, a background process or scheduled task refreshes the hottest or most likely-to-be-requested items ahead of their TTL expiry, keeping them warm for the next wave of requests. This smooths out latency spikes and reduces the risk of a sudden flood of backend calls. Tweaking how long items live (TTL reconfiguration) might delay expiry, but it doesn’t guarantee that the data is present when demand returns, and can increase the window for serving stale data. Changing the eviction policy (LRU) helps some but doesn’t proactively load items before they expire, so it may still miss the chance to serve from cache during a stampede. Invalidation on write focuses on maintaining correctness when data changes, not on preventing stampedes triggered by expirations.

The idea being tested is proactive cache warming. This approach prevents a cache stampede by preloading data into the cache before it expires, so when demand spikes occur, requests are served from the cache rather than forcing a burst of backend load. In practice, a background process or scheduled task refreshes the hottest or most likely-to-be-requested items ahead of their TTL expiry, keeping them warm for the next wave of requests. This smooths out latency spikes and reduces the risk of a sudden flood of backend calls.

Tweaking how long items live (TTL reconfiguration) might delay expiry, but it doesn’t guarantee that the data is present when demand returns, and can increase the window for serving stale data. Changing the eviction policy (LRU) helps some but doesn’t proactively load items before they expire, so it may still miss the chance to serve from cache during a stampede. Invalidation on write focuses on maintaining correctness when data changes, not on preventing stampedes triggered by expirations.