Error waiting for network resource temporarily unavailable

My index.js file:

const Discord = require('discord.js');
const levels = require('discord-xp');
const client = new Discord.Client();
const mongoose = require('./database/mongoose');
const fs = require(`fs`);
require('dotenv').config();
const port = process.env.PORT || 5000;
const host = '0.0.0.0';

const chalk = require('chalk');
const { Player } = require('discord-player');
const Gamedig = require('gamedig');

client.prefix = (`${process.env.PREFIX}`);
client.commands = new Discord.Collection();

client.player = new Player(client);
client.config = require('./config/bot');
client.emotes = client.config.emojis;
client.filters = client.config.filters;

fs.readdirSync('./commands').forEach(dirs => {
    const commands = fs.readdirSync(`./commands/${dirs}`).filter(files => files.endsWith('.js'));

    for (const file of commands) {
        const command = require(`./commands/${dirs}/${file}`);
        console.log(`Loading command ${file}`);
        client.commands.set(command.name.toLowerCase(), command);
    };
});
const player = fs.readdirSync(`./player`).filter(file => file.endsWith('.js'));
const events = fs.readdirSync('./events').filter(file => file.endsWith('.js'));


for (const file of player) {
    console.log(`Loading discord-player event ${file}`);
    const event = require(`./player/${file}`);
    client.player.on(file.split(".")[0], event.bind(null, client));
};
for (const file of events) {
    console.log(`Loading discord.js event ${file}`);
    const event = require(`./events/${file}`);
    client.on(file.split(".")[0], event.bind(null, client));
};

mongoose.init();
client.login(process.env.TOKEN)

My Procfile:

Worker: node index.js

My package.json:

{
    "name": "icrp-bot",
    "version": "1.0.0",
    "description": "Made For ICRP ",
    "main": "index.js",
    "scripts": {
      "test": ".test",
      "start": "node index.js"
    },
    "author": "Bombo43453#1901",
    "license": "ISC",
    "dependencies": {
      "axios": "^0.21.1",
      "baseplayer": "^0.2.9",
      "chalk": "^4.1.1",
      "discord-fivem-api": "^1.0.4",
      "discord-player": "^3.4.0",
      "discord-xp": "^1.1.14",
      "discord.js": "^12.5.3",
      "dotenv": "^8.2.0",
      "ffmpeg-static": "^4.3.0",
      "gamedig": "^3.0.1",
      "log-timestamp": "^0.3.0",
      "moment": "^2.29.1",
      "moment-timezone": "^0.5.33",
      "mongoose": "^5.11.14",
      "node-gyp": "^8.0.0",
      "opus": "0.0.0",
      "opusscript": "0.0.8",
      "pm2": "^4.5.6",
      "python": "0.0.4",
      "rebuild": "^0.1.2"
    }
}

Full Error:

2021-04-23T17:18:33.808571+00:00 heroku[Worker.1]: State changed from down to starting
2021-04-23T17:18:43.196477+00:00 heroku[Worker.1]: Starting process with command `node index.js`
2021-04-23T17:18:43.846098+00:00 heroku[Worker.1]: State changed from starting to up
2021-04-23T17:18:43.854420+00:00 heroku[Worker.1]: Idling
2021-04-23T17:18:43.856605+00:00 heroku[Worker.1]: State changed from up to down
2021-04-23T17:18:43.870047+00:00 heroku[Worker.1]: Idling because quota is exhausted
2021-04-23T17:18:50.422071+00:00 app[Worker.1]: Error waiting for network: Resource temporarily unavailable

Info: this is a simple bot I have made for a fivem server. I tried to host it with heroku and tried to fix it. I tried adding a port const and a const host but that did not fix anything. I also think that my issue is very small and I have 200 hours left on heroku meaning that hours are not the issue. I tried changing the port to 8080 too and that did not help with anything. If you have an idea please tell me.

I am running a docker server on Arch Linux (kernel 4.3.3-2) with several containers. Since my last reboot, both the docker server and random programs within the containers crash with a message about not being able to create a thread, or (less often) to fork. The specific error message is different depending on the program, but most of them seem to mention the specific error Resource temporarily unavailable. See at the end of this post for some example error messages.

Now there are plenty of people who have had this error message, and plenty of responses to them. What’s really frustrating is that everyone seems to be speculating how the issue could be resolved, but no one seems to point out how to identify which of the many possible causes for the problem is present.

I have collected these 5 possible causes for the error and how to verify that they are not present on my system:

1. There is a system-wide limit on the number of threads configured in /proc/sys/kernel/threads-max (source). In my case this is set to 60613.
2. Every thread takes some space in the stack. The stack size limit is configured using ulimit -s (source). The limit for my shell used to be 8192, but I have increased it by putting * soft stack 32768 into /etc/security/limits.conf, so it ulimit -s now returns 32768. I have also increased it for the docker process by putting LimitSTACK=33554432 into /etc/systemd/system/docker.service (source, and I verified that the limit applies by looking into /proc/<pid of docker>/limits and by running ulimit -s inside a docker container.
3. Every thread takes some memory. A virtual memory limit is configured using ulimit -v. On my system it is set to unlimited, and 80% of my 3 GB of memory are free.
4. There is a limit on the number of processes using ulimit -u. Threads count as processes in this case (source). On my system, the limit is set to 30306, and for the docker daemon and inside docker containers, the limit is 1048576. The number of currently running threads can be found out by running ls -1d /proc/*/task/* | wc -l or by running ps -elfT | wc -l (source). On my system they are between 700 and 800.
5. There is a limit on the number of open files, which according to some sources is also relevant when creating threads. The limit is configured using ulimit -n. On my system and inside docker, the limit is set to 1048576. The number of open files can be found out using lsof | wc -l (source), on my system it is about 30000.

It looks like before the last reboot I was running kernel 4.2.5-1, now I’m running 4.3.3-2. Downgrading to 4.2.5-1 fixes all the problems. Other posts mentioning the problem are this and this. I have opened a bug report for Arch Linux.

What has changed in the kernel that could be causing this?

Here are some example error messages:

Crash dump was written to: erl_crash.dump
Failed to create aux thread

Jan 07 14:37:25 edeltraud docker[30625]: runtime/cgo: pthread_create failed: Resource temporarily unavailable

dpkg: unrecoverable fatal error, aborting:
 fork failed: Resource temporarily unavailable
E: Sub-process /usr/bin/dpkg returned an error code (2)

test -z "/usr/include" || /usr/sbin/mkdir -p "/tmp/lib32-popt/pkg/lib32-popt/usr/include"
/bin/sh: fork: retry: Resource temporarily unavailable
 /usr/bin/install -c -m 644 popt.h '/tmp/lib32-popt/pkg/lib32-popt/usr/include'
test -z "/usr/share/man/man3" || /usr/sbin/mkdir -p "/tmp/lib32-popt/pkg/lib32-popt/usr/share/man/man3"
/bin/sh: fork: retry: Resource temporarily unavailable
/bin/sh: fork: retry: No child processes
/bin/sh: fork: retry: Resource temporarily unavailable
/bin/sh: fork: retry: No child processes
/bin/sh: fork: retry: No child processes
/bin/sh: fork: retry: Resource temporarily unavailable
/bin/sh: fork: retry: Resource temporarily unavailable
/bin/sh: fork: retry: No child processes
/bin/sh: fork: Resource temporarily unavailable
/bin/sh: fork: Resource temporarily unavailable
make[3]: *** [install-man3] Error 254

Jan 07 11:04:39 edeltraud docker[780]: time="2016-01-07T11:04:39.986684617+01:00" level=error msg="Error running container: [8] System error: fork/exec /proc/self/exe: resource temporarily unavailable"

[Wed Jan 06 23:20:33.701287 2016] [mpm_event:alert] [pid 217:tid 140325422335744] (11)Resource temporarily unavailable: apr_thread_create: unable to create worker thread