Rocket.Chat/server/startup/presence.js

import { Meteor } from 'meteor/meteor';
import { UserPresence } from 'meteor/konecty:user-presence';

import InstanceStatusModel from '../../app/models/server/models/InstanceStatus';
import UsersSessionsModel from '../../app/models/server/models/UsersSessions';
import { isPresenceMonitorEnabled } from '../lib/isPresenceMonitorEnabled';

Meteor.startup(function() {
	UserPresence.start();

	if (!isPresenceMonitorEnabled()) {
		return;
	}
	// UserPresenceMonitor.start();

	// Remove lost connections
	const ids = InstanceStatusModel.find({}, { fields: { _id: 1 } }).fetch().map((id) => id._id);

	const update = {
		$pull: {
			connections: {
				instanceId: {
					$nin: ids,
				},
			},
		},
	};
	UsersSessionsModel.update({}, update, { multi: true });
});