uxmlib-redis

The smallest useful cross-server primitive: publish a byte[] to a named channel, subscribe to a named channel. It owns the wire and nothing else. Encoding, routing and echo suppression are yours.

This module depends on nothing internal, not even uxmlib-common. Lettuce is a compile-only soft dependency, so it is not shipped with the module.

RedisBus bus = new LettuceRedisBus(RedisClient.create("redis://localhost:6379"), logger::warning);

bus.subscribe("party-updates", frame -> applyUpdate(decode(frame)));
bus.publish("party-updates", encode(update));

bus.healthy();
bus.close();

What it guarantees

Publish never blocks. It is fire-and-forget over the client's event loop and may be called from any thread.

Publish fails degraded. A publish while the connection is down is dropped and warned about, not thrown. A Redis outage degrades cross-server messaging; it does not take the server with it.

Subscriptions reconnect. Each subscription re-establishes itself after a connection drop, so a node that lost Redis for thirty seconds resumes receiving without a restart.

Warnings are rate-limited. A connection that is down produces one warning periodically rather than one per publish.

What you have to do

Bridge threads yourself. subscribe delivers frames on the client's pub/sub thread. Nothing Bukkit may be touched there. Hop through the Scheduler first.

bus.subscribe("party-updates", frame -> scheduler.global(() -> apply(decode(frame))));

Suppress your own echo. Redis pub/sub delivers a publisher its own messages. A node that both publishes and subscribes on a channel will receive what it just sent, so stamp your frames with a node id and drop your own.

Choose an encoding. The frame is opaque bytes. Protobuf, your own binary format, or a UTF-8 string, whichever fits.

When to use this rather than storage sync

uxmlib-storage builds its DataSynchronizer on the same idea with a String payload and a LocalDataSynchronizer fallback for single-node servers. Reach for uxmlib-redis when the payload is a codec's output rather than an identifier, or when you want the primitive with no other module attached.