BRPOP doesn't actually work

[alwhiting]

Hi,

Sorry if I'm missing something obvious but BRPOP does not seem to actually resolve when a queued item becomes available. If something is present when BRPOP is initiated it immediately resolves otherwise it 'blocks' until timeout and resolves with null.

Example:

import { Redis } from 'ioredis';

(async () => {
    const redis = new Redis();

    setTimeout(() => {
        redis.lpush('some-queue', 'a queued thing');
    }, 1000);

    const start = Date.now();

    do {
        const queuedThing = await redis.brpop('some-queue', 10);
        if (!queuedThing) {
            console.log('Timeout waiting for queue, elapsed:', Date.now() - start);
            continue;
        }

        console.log('Got thing from queue:', queuedThing, 'elapsed:', Date.now() - start);
        process.exit(0);
    } while (true);

})();

Output:

ts-node example.ts
Timeout waiting for queue, elapsed: 10041
Got thing from queue: [ 'some-queue', 'a queued thing' ] elapsed: 10043

A timeout should not occur right? The loop should block for 1 second and then process the LPUSHed event and then exit.

redis-server 7.4.1
ioredis 5.4.1
node 20.15.1

edit-- I tested directly w/ redis-cli and it works as expected.

[RubensBR]

In this case you need a second connection:

import { Redis } from 'ioredis';

(async () => {
    const producer = new Redis();
    const consumer = new Redis();

    setTimeout(() => {
        producer.lpush('some-queue', 'a queued thing');
    }, 1000);

    const start = Date.now();

    do {
        const queuedThing = await consumer.brpop('some-queue', 10);
        if (!queuedThing) {
            console.log('Timeout waiting for queue, elapsed:', Date.now() - start);
            continue;
        }

        console.log('Got thing from queue:', queuedThing, 'elapsed:', Date.now() - start);
        process.exit(0);
    } while (true);

})();