TypeError: Cannot read properties of undefined (reading 'address') when subscribing to channels in Redis Cluster

[jdnichollsc]

Description

When attempting to subscribe to Redis channels in a Redis Cluster environment, the client throws the following error:

Cluster issue for channel: general:{So11111111111111111111111111111111111111112}:{4yrHms7ekgTBgJg77zJ33TsWrraqHsCXDtuSZqUsuGHb}. This is a known issue with Redis Cluster Pub/Sub.
[Redis Subscribe - Cluster Issue] Error: TypeError: Cannot read properties of undefined (reading 'address')
    at RedisClusterSlots._RedisClusterSlots_initiatePubSubClient (/Users/jdnichollsc/dev/print-world/print.lol-backend/node_modules/@redis/client/dist/lib/cluster/cluster-slots.js:392:23)
    at RedisClusterSlots.getPubSubClient (/Users/jdnichollsc/dev/print-world/print.lol-backend/node_modules/@redis/client/dist/lib/cluster/cluster-slots.js:133:118)
    at Commander.SUBSCRIBE (/Users/jdnichollsc/dev/print-world/print.lol-backend/node_modules/@redis/client/dist/lib/cluster/index.js:151:78)
    at RedisPubSubManager.subscribe (/Users/jdnichollsc/dev/print-world/print.lol-backend/apis/ws-ui/src/RedisPubSubManager.ts:129:19)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
    at ChannelSubscriptionManager.handleChannelSubscription (/Users/jdnichollsc/dev/print-world/print.lol-backend/apis/ws-ui/src/ChannelSubscriptionManager.ts:119:9)

This error occurs in the RedisClusterSlots._RedisClusterSlots_initiatePubSubClient method when the client tries to create a dedicated Pub/Sub client for the cluster. The issue appears to be that the client is unable to properly initialize the Pub/Sub client for the cluster, possibly due to an undefined node reference.

Environment

• Redis Server Version: 7.x (Cluster mode enabled)
• Node Redis Version: 1.6.0
• Node.js Version: v20.10.0
• Platform: MacOS, Apple M2 Max

Steps to Reproduce

1. Set up a Redis Cluster with multiple nodes (in my case, nodes on ports 7100-7105)
2. Create a Redis client using the node-redis library and connect to the cluster
3. Attempt to subscribe to a channel using the subscribe method
4. The error occurs during the subscription process

Code Example

import { createCluster } from 'redis';

const redisClient = createCluster({
  rootNodes: [
    { url: 'redis://localhost:7100' },
    { url: 'redis://localhost:7101' },
    // ... other nodes
  ]
});

// This works fine
await redisClient.publish('trade:{So11111111111111111111111111111111111111112}:{4yrHms7ekgTBgJg77zJ33TsWrraqHsCXDtuSZqUsuGHb}', JSON.stringify({ data: 'test' }));

// This fails with the error
await redisClient.subscribe('trade:{So11111111111111111111111111111111111111112}:{4yrHms7ekgTBgJg77zJ33TsWrraqHsCXDtuSZqUsuGHb}', (message) => {
  console.log(message);
});

Expected Behavior

The client should successfully subscribe to the channel and receive messages published to it.

Actual Behavior

The client throws the error TypeError: Cannot read properties of undefined (reading 'address') when attempting to subscribe.

Additional Context

• PUBLISH operations work correctly on the same channels
• Using the Redis CLI directly to subscribe to these channels works without issues
• The error specifically occurs in the cluster client's Pub/Sub initialization logic

This appears to be a bug in how the Redis Cluster client handles Pub/Sub subscriptions, possibly related to how it manages node connections for Pub/Sub operations.

[asynchroza]

Are you certain that your cluster is configured correctly? The library doesn’t perform any preliminary checks to verify whether a node is set as cluster-enabled or that your cluster was set up correctly. To confirm if your configuration is being recognized, you can easily validate it by adding a breakpoint or a console log after line 390 in /@redis/client/dist/lib/cluster/cluster-slots.js to log the master and replica nodes. They shouldn't be empty.

Here's the code with which I got it working:

import { createCluster } from 'redis';

const cluster = createCluster({
    rootNodes: [
        {
            url: 'redis://127.0.0.1:6379'
        },
        {
            url: 'redis://127.0.0.1:6380'
        },
        {
            url: 'redis://127.0.0.1:6381'
        },
    ],
    // useReplicas: true
});

cluster.on('error', (err) => console.log('Redis Client Error', err));

await cluster.connect();

const newCluster = cluster.duplicate();

await cluster.subscribe('trade:{So11111111111111111111111111111111111111112}:{4yrHms7ekgTBgJg77zJ33TsWrraqHsCXDtuSZqUsuGHb}', (message) => {
    console.log(message);
});

await newCluster.connect();
await newCluster.publish('trade:{So11111111111111111111111111111111111111112}:{4yrHms7ekgTBgJg77zJ33TsWrraqHsCXDtuSZqUsuGHb}', JSON.stringify({ data: 'test' }));