Configuration, codecs, and client ownership

Make defaults explicit

Setting	1.11.0 default	Meaning
cacheName	redisson-near-cache	Redis map name
maxLocalSize	10_000	Maximum local entries per JVM
timeToLive	null	No Redis TTL
maxIdle	null	No idle expiry
syncStrategy	INVALIDATE	Invalidate after another client writes
reconnectionStrategy	CLEAR	Clear local entries after reconnect
evictionPolicy	LRU	Local eviction policy

Use a service/data/environment-specific name instead of the default. With both durations unset, Redis entries do not expire because of time.

Validation and scope

Names cannot be blank, local size must be positive, and configured TTL/idle durations must be greater than zero.

val config = redissonNearCacheConfig {
    cacheName = "catalog:products:v1"
    maxLocalSize = 2_000
    timeToLive = Duration.ofMinutes(15)
    maxIdle = Duration.ofMinutes(5)
}

TTL applies to Redis entries. Local size and eviction apply to each JVM. They are not two spellings of one capacity limit.

Codec as a data contract

The default near-cache codec is RedissonCodecs.LZ4Fory. A codec is a wire format, not just a compression toggle. If old and new deployments share one map with incompatible codecs, reads can fail. Use a compatible rollout or versioned map names.

JCache Configuration<K, V> also carries key/value types, expiry, loader, and writer. Reopening an existing name does not guarantee that a new configuration replaces the old one.

One client owner

Usually the DI container creates and closes one RedissonClient. Near-cache close() and memoizer clear() do not shut it down. Config-based JCache creation can involve provider-owned clients, so verify the global manager/provider lifecycle separately and isolate test cache names.

Source and tests

• RedissonNearCacheConfig.kt
• RedissonCaches.kt
• RedissonNearCacheConfigTest.kt