RocketChat/Rocket.Chat

import { Presence } from '@rocket.chat/core-services';
import { InstanceStatus } from '@rocket.chat/instance-status';
import { Accounts } from 'meteor/accounts-base';
import { Meteor } from 'meteor/meteor';
import { throttle } from 'underscore';

// update connections count every 30 seconds
const updateConns = throttle(function _updateConns() {
    void InstanceStatus.updateConnections(Meteor.server.sessions.size);
}, 30000);

Meteor.startup(() => {
    const nodeId = InstanceStatus.id();

    Meteor.onConnection((connection) => {
        const session = Meteor.server.sessions.get(connection.id);

        connection.onClose(async () => {
            if (!session) {
                return;
            }

            await Presence.removeConnection(session.userId, connection.id, nodeId);
            updateConns();
        });
    });

    process.on('exit', async () => {
        await Presence.removeLostConnections(nodeId);
    });

    Accounts.onLogin((login: any): void => {
        if (!login.connection.id) {
            return;
        }

        // validate if it is a real WS connection and is still open
        const session = Meteor.server.sessions.get(login.connection.id);
        if (!session) {
            return;
        }

        void (async function () {
            await Presence.newConnection(login.user._id, login.connection.id, nodeId);
            updateConns();
        })();
    });

    Accounts.onLogout((login): void => {
        void Presence.removeConnection(login.user?._id, login.connection.id, nodeId);

        updateConns();
    });
});