In a cache-aside cache invalidation strategy, what should happen on a data write?

• A. The cache should be populated first before writing to the source.
• B. The cache should be ignored on write.
• C. The cache should be fully rebuilt periodically.
• D. The cache should be invalidated or updated to reflect the new value.

Answer: (C)

In a cache-aside pattern, the writes go to the underlying data store first, and then the cache is made consistent with that new value. After a write, the cache entry for that data should be invalidated or updated to reflect the change. Invalidation ensures the next read reloads fresh data from the source, while updating the cached value keeps reads fast without serving stale data. Fully rebuilding the cache periodically isn’t how cache-aside handles immediate writes, and ignoring the cache on write would leave stale data in the cache.