Redis Cache

RedisCacheClient wraps Lettuce coroutines commands and provides full CacheClient support including per-field TTL (requires Redis 7.4+).

Setup

val cache: CacheClient = RedisCacheClient("redis://localhost:6379")

The constructor accepts any Lettuce URI string, including:

redis://[:password@]host[:port][/database]
rediss://host:port          # TLS
redis-sentinel://...

Per-field TTL

RedisCacheClient implements hexpire using HEXPIRE (Redis 7.4+). When you pass fieldExpire to a controller method, it calls HEXPIRE after each HSET.

On Redis < 7.4 the command fails on the first call; the client logs a one-time warning and degrades gracefully — cached data is served without a TTL.

controller.set(users, User.serializer(), fieldExpire = Duration.ofHours(1)) {
    findOneAndUpdate(filter, update)
}

Whole-hash TTL

expire maps to EXPIRE and applies to the entire hash key:

controller.getAll(users, User.serializer(), expire = Duration.ofMinutes(10)) {
    find().toList()
}