Configuring Eviction Policies

1. Understanding Eviction Policies

When	Trigger
used_memory ≥ maxmemory	Policy selects keys to remove before each write

2. Using NoEviction Policy

Policy	Behavior
noeviction	Reject writes with OOM error; reads still served

3. Using AllKeys-LRU Policy

Policy	Behavior
allkeys-lru	Evict least-recently-used across all keys

4. Using Volatile-LRU Policy

Policy	Behavior
volatile-lru	Evict LRU among keys with TTL

5. Using AllKeys-LFU Policy

Policy	Behavior
allkeys-lfu	Evict least-frequently-used (counter with decay)

6. Using Volatile-LFU Policy

Policy	Behavior
volatile-lfu	LFU restricted to keys with TTL

7. Using AllKeys-Random Policy

Policy	Behavior
allkeys-random	Evict random key (cheap, no metadata)

8. Using Volatile-Random Policy

Policy	Behavior
volatile-random	Random key among those with TTL

9. Using Volatile-TTL Policy

Policy	Behavior
volatile-ttl	Evict key with smallest remaining TTL

10. Configuring LFU Parameters

Directive	Description
lfu-log-factor 10	Higher = slower counter growth
lfu-decay-time 1	Minutes per counter decrement

11. Monitoring Eviction Statistics

Source	Field
INFO stats	evicted_keys, evicted_clients
OBJECT FREQ key	LFU counter (requires LFU policy)
OBJECT IDLETIME key	Seconds since last access (requires LRU)