If you have ever used google docs/google drive, they have a feature where two users can simutaneously edit a document and the document updates it live, as if you had MS Word open but with two mouse and two keyboards.
I’m interested as to how this actually works. I’m pretty sure they don’t write to a DB and check it every second, so what are the mechanics behind it? Could you explain the basic concept as to how they do this?
PS: I’m not sure what to tag this with, any suggestions would be nice.
Any time a user makes a change to an open document or navigates around it, an asynchronous request is made to Google Docs informing them of this. The GDoc server then uses the HTTP Comet request opened by other clients to inform them of that user’s actions.
Ref: Read about Comet at Wikipedia