Redis UNSUBSCRIBE doesn't delete channels - redis

Question

sub.unsubscribe do not delete channels, how can I delete channels alternatively?
I tried channel.close() or channel.quit() but that didn't work!
Code:
let roomChannelName = room_${roomId}_server;
let sub = redis.createClient(redisConfig);
const channel = this.scServer.exchange.channel(roomChannelName);
sub.unsubscribe(roomChannelName);
this.scServer.exchange.destroyChannel(roomChannelName)

Answer 1

You CANNOT delete a channel manually.
If there's no client subscribes to a channel, Redis will delete the channel automatically.

Answer 2

sub.unsubscribe(roomChannelName);
this.scServer.exchange.destroyChannel(roomChannelName)
I'm a little unclear which library this is, but: "destroy channel" isn't a concept in redis. A channel is active as long as one or more connections exist that are listening to it (via subscribe or psubscribe). It doesn't "exist" in any other semantic sense - it doesn't need to be declared ahead of time, nor does it need to be destroyed. If you want to see whether a channel has listeners, you can use either:
pubsub numsub {channel name}
or, if you don't mind sending dummy data - just publish to it:
publish {channel name} {dummy value}
either of these will return the count of subscribers for the channel:
127.0.0.1:6379> pubsub numsub foo
1) "foo"
2) (integer) 0
127.0.0.1:6379> publish foo bar
(integer) 0
I don't know if your library has an API to expose this, but ultimately: you don't have to do anything here. You don't need to clean up after yourself with pub/sub.
If your sub.unsubscribe(roomChannelName); call failed to issue an unsubscribe/punsubscribe, then that is a library issue, not a redis issue.

Answer 3

you can try somthing like that ,
use psubscribe and handle only if the pmesseege enter data
fits your needs..
const RedisInstance = require("./redis");
const Subscriber = new RedisInstance().client;
const socketsDataList = require('./activeSocketsList');
const orderManager = require("./orderManager");
class RedisSubscriber {
subscriber = Subscriber;
constructor() {
this.subscriber.psubscribe(`order_*`);
this.subscriber.on("pmessage", (pattern , channel , order) => this.onOrder(
channel , order) );
}
async getSocketByDeviceId(deviceId) {
return await socketsDataList.checkIfSocketExistsForThisDevice(deviceId);
}
async onOrder(channel , order ) {
const deviceId = channel.split("_")[1];
try {
const socketObj = await this.getSocketByDeviceId(deviceId);
if (socketObj['error']) {
console.log(socketObj['error']);
} else {
const socket = socketObj['activeSocket'].socket
await orderManager.sendOrderToClient( socket , order);
console.log({message: 'success'})
}
} catch (error) {
console.log(error)
}
}
}
module.exports = RedisSubscriber;