10. Redis: cache, queue, locks, rate limiting#

@damatjs/redis provides batteries-included Redis helpers. Initialize the client once (the framework does this when redisUrl is set), then use the helpers.

import {
  initRedis, cacheGet, cacheSet,
  checkRateLimit, withLock, RedisQueue,
} from "@damatjs/redis";

initRedis(process.env.REDIS_URL!);

// cache with TTL
await cacheSet("user:1", user, 60);
const cached = await cacheGet("user:1");

// sliding-window rate limit
const { allowed } = await checkRateLimit("ip:1.2.3.4", { limit: 100, windowMs: 60_000 });

// distributed lock
await withLock("import-job", { ttlMs: 30_000 }, async () => { /* critical section */ });

// background queue
const queue = new RedisQueue("emails");
await queue.enqueue({ to: "a@b.co" });

It also covers sessions and counters. See the redis internals for every helper and its options.