Change streams

The change streams functionality was introduced in version 3.6 and updated in versions 4.0 and 5.1, making it a safe and efficient way to listen for database changes.

Introduction

The fundamental problem that change streams solve is the need for applications to react immediately to changes in the underlying data. Modern web applications need to be reactive to data changes and refresh the page view without reloading the entire page. This is one of the problems that frontend frameworks (such as Angular, React, and Vue.js) are solving. When a user performs an action, the frontend framework will submit the request to the server asynchronously and refresh the relevant fragment of the page based on the response from the server.

Thinking of a multiuser web application, there are cases where a database change may have occurred as a result of another user’s action. For example, in a project management Kanban board, user A may be viewing the Kanban board...