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Eviction Policies

When the cache is full, an eviction policy decides what to drop. MountSQLI’s MemoryCache supports three.

Policies

Section titled “Policies”
Policy Evicts Best when
LRU least recently used general purpose, recency matters
LFU least frequently used hot keys should survive
FIFO first in, first out simple, order-based churn

Configure

Section titled “Configure”
import { CacheManager, MemoryCache } from "@mountsqli/cache";


const manager = new CacheManager({
  l1: new MemoryCache({ max: 1000, policy: "LRU" }),
});

How each works

Section titled “How each works”
  • LRU tracks last access time; drops the stalest.
  • LFU counts accesses; drops the least popular.
  • FIFO keeps an insertion queue; drops the oldest entry.

Best practices

Section titled “Best practices”
  • Start with LRU — it fits most read patterns.
  • Use LFU for very skewed “hot key” workloads.
  • Size max to your working set; too small = thrash, too big = memory bloat.

Common mistakes

Section titled “Common mistakes”
  • Setting max too low — every read misses.
  • Using FIFO when recency matters (drops still-useful entries).
Section titled “Related”