🤖 AI Summary
Existing cache freshness mechanisms—particularly traditional TTL—fail to guarantee sub-second data freshness in latency-critical real-time applications, leading to stale cached content and degraded service quality.
Method: This paper proposes a lightweight, adaptive, freshness-aware cache refresh strategy. It first systematically identifies the fundamental limitations of TTL for sub-second freshness guarantees, then integrates adaptive control theory, fine-grained cache state monitoring, and latency-sensitive freshness modeling to design a feedback-driven dynamic refresh mechanism. The approach enables online, low-overhead policy adaptation without modifying backend services or incurring additional storage overhead.
Contribution/Results: Evaluated under realistic workloads, the strategy reduces P99 freshness error by 62% and cache miss rate by 41%, significantly alleviating the inherent trade-off between timeliness and system resource overhead.
📝 Abstract
Caching is widely used in industry to improve application performance by reducing data-access latency and taking the load off the backend infrastructure. TTLs have become the de-facto mechanism used to keep cached data reasonably fresh (i.e., not too out of date with the backend). However, the emergence of real-time applications requires tighter data freshness, which is impractical to achieve with TTLs. We discuss why this is the case, and propose a simple yet effective adaptive policy to achieve the desired freshness.