How to correctly count online on the site?

Question

Yii

It is necessary to implement a count of active users on the site at the moment. It is not necessary to count those who opened the site and forgot about it for half a day. At what it would be desirable to make updating in real time. That is, if, for example, a person closes the tab, then it will immediately be displayed to others. I will update the value through web sockets, so the main thing is to count online on the server on time, competently and with good performance.

Answer 1

в afterAction контроллеров юзеру присваивать переменную lastActive в которую писать unix метку времени, например в базу ее писать. Потом делать выборку пользователей у которых lastActive больше, чем сейчас минус 15 минут например.
Можно вынести это в поведение или в компонент и подключить в конфиге.

Answer 2

> I will update the value through web sockets
and what will act as a queue server? If it is a node, then store it in a variable thread. And you can increment/decrement on connect/disconnect events and then send the updated value to subscribers.