Cluster (network state)

What the servers of a minigame network know about each other: every server's arenas and the players on their way to one, over MySQL / MariaDB or Redis. Game servers write their arenas; hubs, proxies and other game servers read them. SurvivalGames and its hub plugin are built on it.

Part	Does
Arenas	Each game server publishes its arenas every few seconds; an arena not refreshed for 15 s is gone
Joins	A sender writes "this player goes to that arena", then moves the player; the game server takes them in
Seats	reserve checks the arena's free places and writes the join in one atomic step
Quick Join	The fullest joinable arena, the one starting soonest
Locks	Network-wide locks with expiry (e.g. one server editing a map)

Cluster cluster = Cluster.connect(settings, getLogger());     // MySQL or Redis, from ClusterSettings
cluster.publish("sg-1", arenas);                                // a game server, every few seconds
cluster.arenas().thenAccept(all -> updateMenu(all));            // a hub
cluster.reserve(player, "sg-1", "breeze").thenAccept(ok -> {    // a seat, then send the player
    if (ok) connect(player, "sg-1");
});

Every call returns a CompletableFuture; nothing blocks the main thread.

• MySQL: two tables, polled every couple of seconds.
• Redis: a hash per server with a TTL, a key per traveling player, pub/sub so menus update at once.

Cluster isn't part of the EranoAPI plugin: shade it into your plugin and relocate me.erano.com.api.cluster, Jedis, HikariCP and the MariaDB driver. See the Cluster README.