Day 23 of #DistributedDilemmas: Distributed caching layers often become consistency nightmares

As cache invalidation schemes attempt to maintain coherence, real-world implementations often reveal why short TTLs (Time-to-Live) can outperform complex invalidation logic in many scenarios.

While purists argue TTLs “kick the can down the road,” pragmatic engineering often favors their simplicity. As Meta’s infrastructure team concluded: “Sometimes 99.9% consistency with 1-minute TTLs is better than 99.999% consistency with unmaintainable invalidation logic”. (Read more: https://engineering.fb.com/2022/06/08/core-infra/cache-made-consistent/)

The choice ultimately depends on whether your use case can tolerate bounded staleness versus requiring absolute accuracy.

Day 23 on X ↗