How to make a notification about new messages?

Question

1C-Bitrix

Site on 1C-Bitrix. It has a discussion board and an exchange of drugs. Both services are written in highloadblock.
How minimally expensive in terms of server resources to make notifications to users a pop-up message when a response appears. There are many users.

Answer 1

If the user is a lot, then you can quickly do it only with a queue server like RabbitMQ Start a
queue and throw messages marked as the recipient's id there, all recipients read the queue and select messages marked with their id.

Answer 2

In the edition of Expert, Small Business and Business there is a Push'n'pull module

The Push and Pull module allows you to organize transport for sending instant commands. The implementation of this functionality as a separate module allows any other module (including third-party modules) using the API to send instant notifications and messages to clients.