socket.io ioredis Connection in subscriber mode, only subscriber commands may be used

[rjsalem]

When I am trying to do and io.emit(), I receive this error:

Error: Connection in subscriber mode, only subscriber commands may be used
at Redis.sendCommand (/home/ubuntu/ridemetry-iridium-mo/node_modules/ioredis/lib/redis.js:562:20)
at tryConnection (/home/ubuntu/ridemetry-iridium-mo/node_modules/ioredis/lib/cluster/index.js:537:13)
at Cluster.sendCommand (/home/ubuntu/ridemetry-iridium-mo/node_modules/ioredis/lib/cluster/index.js:479:3)
at Cluster.publish (/home/ubuntu/ridemetry-iridium-mo/node_modules/ioredis/lib/commander.js:131:17)
at Redis.broadcast (/home/ubuntu/ridemetry-iridium-mo/node_modules/socket.io-redis/index.js:414:11)
at Namespace.emit (/home/ubuntu/ridemetry-iridium-mo/node_modules/socket.io/lib/namespace.js:230:16)
at Server.(anonymous function) [as emit] (/home/ubuntu/ridemetry-iridium-mo/node_modules/socket.io/lib/index.js:456:29)
at deviceService.getDeviceByImei.then.device (/home/ubuntu/ridemetry-iridium-mo/server.js:175:32)
at tryCatcher (/home/ubuntu/ridemetry-iridium-mo/node_modules/bluebird/js/release/util.js:16:23)
at Promise._settlePromiseFromHandler (/home/ubuntu/ridemetry-iridium-mo/node_modules/bluebird/js/release/promise.js:512:31)
at Promise._settlePromise (/home/ubuntu/ridemetry-iridium-mo/node_modules/bluebird/js/release/promise.js:569:18)
at Promise._settlePromise0 (/home/ubuntu/ridemetry-iridium-mo/node_modules/bluebird/js/release/promise.js:614:10)
at Promise._settlePromises (/home/ubuntu/ridemetry-iridium-mo/node_modules/bluebird/js/release/promise.js:693:18)
at Async._drainQueue (/home/ubuntu/ridemetry-iridium-mo/node_modules/bluebird/js/release/async.js:133:16)
at Async._drainQueues (/home/ubuntu/ridemetry-iridium-mo/node_modules/bluebird/js/release/async.js:143:10)
at Immediate.Async.drainQueues (/home/ubuntu/ridemetry-iridium-mo/node_modules/bluebird/js/release/async.js:17:14)
at runCallback (timers.js:789:20)
at tryOnImmediate (timers.js:751:5)
at processImmediate [as _immediateCallback] (timers.js:722:5)

Code :

const app = require('express')();
const server = require('http').Server(app);
const io = require('socket.io')(server);
const Redis = require('ioredis');
const redisAdapter = require('socket.io-redis');
const cluster = new Redis.Cluster([ { port: Number(process.env.REDIS_PORT), host: process.env.REDIS_HOST } ]);
io.adapter(redisAdapter({ pubClient: cluster, subClient: cluster }));
io.emit('message', { test: 'test' });

[chumager]

you MUST use direrents redis clients for pub and sub when you define pub and sub...

In subscription mode redis only accepts some commands, so you can't emit with the pub client if it is the same, standar redis client "node_redis" use .duplicate(), with ioredis you need yo instance 2 clusters...

regards

[darrachequesne]

@chumager is right, the example in the README was not correct, the same client was used for both publishing and subscribing. I updated the README with the correct example:

const io = require('socket.io')(3000);
const redisAdapter = require('socket.io-redis');
const Redis = require('ioredis');

const startupNodes = [
  {
    port: 6380,
    host: '127.0.0.1'
  },
  {
    port: 6381,
    host: '127.0.0.1'
  }
];

io.adapter(redisAdapter({
  pubClient: new Redis.Cluster(startupNodes),
  subClient: new Redis.Cluster(startupNodes)
}));