Redis connections increasing from nodejs - node.js

Question

I am having two connections from nodejs to Redis:
to set a list variable
to subscribe to a channel
The longer the socket is running, the more connections I get.
I have tried to set timeout values in redis, tried to close redis connections on close of socket.io
var Redis = require('ioredis');
var globalRedis = new Redis({
port: process.env.REDIS_PORT, // Redis port
host: process.env.REDIS_HOST, // Redis host
family: 4, // 4(IPv4) or 6(IPv6)
db: 1
});
[...]
io.sockets
.on('connection', socketioJwt.authorize({
secret: process.env.JWT_SECRET,
timeout: 15000 // 15 seconds to send the authentication message
}))
.on('authenticated', function(socket) {
var redis = new Redis({
port: process.env.REDIS_PORT,
host: process.env.REDIS_HOST,
// password: process.env.REDIS_PASSWORD,
family: 4,
db: 1
});
socket.on('disconnect', function() {
redis.unsubscribe('channel-'+socket.decoded_token.uid);
});
socket.on('error', function() {
redis.unsubscribe('channel-'+socket.decoded_token.uid);
});
redis.subscribe('channel-'+socket.decoded_token.uid);
redis.on('message', function(channel, message) {
message = JSON.parse(message);
socket.emit('message', message);
});
});
function disconnectUser(userObject){
globalRedis.sismember('online_uids', userObject.uid).then(function(){
globalRedis.srem('online_users', userObject.nickname).then(console.log(userObject.nickname + ' disconnected!'));
globalRedis.srem('online_uids', userObject.uid);
});
}
const port = process.env.SOCKET_PORT;
const host = process.env.SOCKET_URL;
const logger = () => console.log(`Listening: http://${host}:${port}`);
http.listen(port, host, logger);
So the connection in globalRedis is always active and no problem whatsoever.
But as time goes by the subscribed connections in redis increase, even if I unsubscribe on disconnect and on error.
Any ideas?
P.S.: sorry for my bad code and knowledge, this is my first nodejs ever.

Answer 1

You are creating a new redis client for every authenticated socket connection and then it is subscribing to the channel. Unsubscribing from the channel doesn't close the connection also timeout only applies to normal clients and it does not apply to Pub/Sub clients.
Close redis client connection on socket disconnect or error.
redis.quit()
Reference Redis Docs

Answer 2

So just in case anyone stumbles upon the same issue. I ended up putting each user into his own channel:
io.sockets
.on('connection', socketioJwt.authorize({
secret: process.env.JWT_SECRET,
timeout: 15000 // 15 seconds to send the authentication message
}))
.on('authenticated', function(socket) {
socket.join(socket.decoded_token.uid);
connectUser(socket.decoded_token);
socket.on('disconnect', function() {
disconnectUser(socket.decoded_token);
});
socket.on('error', function() {
disconnectUser(socket.decoded_token);
});
socket.on('connect_failed', function() {
disconnectUser(socket.decoded_token);
});
socket.on('reconnect_failed', function() {
disconnectUser(socket.decoded_token);
});
socket.on('message', function(message){
socket.emit('message', message);
});
});
redis.on('message', function(channel, msg) {
// console.log(msg);
try{
message = JSON.parse(msg);
channels = message.data.socketchannel
channels.forEach(recipient => {
io.sockets.in(recipient).emit('message', message);
})
}
catch(e) {
const fs = require('fs');
fs.writeFile("./log/errorlog"+ new Date().toJSON().slice(0,10), e, function(err) {
if(err) {
return console.log(err);
}
})
}
});