Mekik.Redis 0.7.0

Mekik.Redis

Redis horizontal-scale backends for mekik — the two ports a fleet needs, so a single-node app becomes N nodes behind a load balancer with no engine changes. The .NET mirror of @mekik/redis; see docs/SCALING.md for the model.

• RedisTurnLock — a SET NX PX single-writer lease per conversation, so only one node runs a turn at a time. The held lease heartbeats its own TTL, so a long streaming run never lets the lock lapse; a crashed owner's lock expires.
• RedisBackplane — Redis Pub/Sub cross-node fan-out, so every node holding a tab of a conversation re-fans each frame to its own sockets.

using Mekik;
using StackExchange.Redis;

var redis = await ConnectionMultiplexer.ConnectAsync(builder.Configuration["Redis"]!);

var app = new MekikApp(new MekikOptions
{
    Graph = graph,
    TurnLock  = new RedisTurnLock(redis),   // single-writer lease across nodes
    Backplane = new RedisBackplane(redis),  // cross-node fan-out
});

Pass nothing and mekik keeps its process-local defaults (LocalTurnLock, NoopBackplane) — scaling is entirely opt-in, exactly like History and Conversations.

Built on StackExchange.Redis: share one IConnectionMultiplexer across both. The turn lock uses its database; the backplane uses its subscriber (a multiplexer already manages the subscribe-mode connection internally, so no second connection to wire up).

RedisTurnLock options

new RedisTurnLock(redis, new RedisTurnLockOptions
{
    KeyPrefix = "mekik",                  // share one Redis across apps. Default "mekik".
    Ttl       = TimeSpan.FromSeconds(30), // lock TTL; must exceed a turn's worst case.
    Heartbeat = TimeSpan.FromSeconds(10), // self-renew interval. Default Ttl / 3.
    OnLost    = convId => logger.LogWarning("turn lease lost {Conv}", convId),
});

The lease is token-checked: a node can only renew or release a lock it still holds, so a slow node whose TTL lapsed can never free the new owner's lock. The key is {KeyPrefix}:lock:{conversationId}. The lease releases on DisposeAsync (the engine disposes it when the turn ends).

RedisBackplane options

new RedisBackplane(redis, new RedisBackplaneOptions { KeyPrefix = "mekik" });

The channel is {KeyPrefix}:bp:{conversationId}. The returned subscription unsubscribes on DisposeAsync.

Routing

A fleet needs sticky-by-conversationId ingress so a conversation's connections land on its owner node (the backplane is a fallback for the re-home window, not the steady-state path). conversationId travels in the WebSocket query string so an edge proxy can hash on it without parsing frames. See docs/SCALING.md.

MIT