Write Through Caching

Write through caching is a cache consistency strategy where data is written simultaneously to both the cache and the underlying persistent storage (like a database) on every write operation. This ensures that the cache and storage are always synchronized, preventing stale data in the cache. It prioritizes data consistency over write performance, as writes are slower due to the dual-write overhead.

Also known as: Write-Through, Write-Through Cache, Write-Through Strategy, Synchronous Write Cache, WT Cache

Why learn Write Through Caching?

Developers should use write through caching in applications where data consistency is critical and cannot tolerate stale reads, such as financial systems, e-commerce inventory management, or real-time collaborative tools. It's ideal when the cost of reading stale data (e.g., incorrect account balances) outweighs the performance penalty of slower writes, ensuring that all reads from the cache reflect the latest updates.

Learning Resources

• docs: AWS Documentation: Caching Strategies
• tutorial: Microsoft Learn: Caching Guidance
• video: YouTube: Write Through vs Write Back Caching
• book: Book: Designing Data-Intensive Applications by Martin Kleppmann