What logic can be used to make the form of active users, as here when choosing sellers online https://funpay.com/chips/56/?

Question

Django

What logic can be implemented for the form of online sellers?

Answer 1

Option 1: Use sockets
Pros:

• Consumes few resources
  
• Allows you to make chats, notifications, etc. more productively.
  

Minuses:

• Difficult to set up.
  

Option 2: On each user action, record the time and show users active in the last N minutes
Pros:

• No consumption of extra resources
  

Minuses:

• Low level of liveliness (offline users may appear alive)
  

Option 3: Use JS to poll the server every N-seconds (and update the time, as in v.2)
Cons: high resource consumption