This article explains why Redisson's RMapCache.size() includes expired entries, demonstrates how to obtain the exact number of currently valid key‑value pairs using keySet().size() or readAllEntrySet().size(), and provides performance tips and a real‑world e‑commerce use case.
Learn how the open‑source hcache tool analyzes Linux page‑cache usage, provides global and per‑process cache rankings, supports multiple output formats, and offers step‑by‑step installation and command examples to pinpoint memory hogs, troubleshoot OOM alerts, and optimize system performance.
The article details practical monitoring strategies for both remote Redis and local Caffeine caches in high‑traffic game services, including prefix‑based Redis key tracking, Aspect‑oriented instrumentation, Caffeine statistics collection, and real‑world case studies that illustrate how these metrics identify hot‑keys, cache‑miss spikes, and reduce system load.
