I`m want to make webapp with Django which displays a map for every user on the main page. What I want to have:

1.Every user can add a marker to map and every other user see those markers immediately.
2.Every user can delete marker if he is owner of that marker and other user will see those changes immediately.
3.If user A "is intrested" with user B (this information is stored in DB) he (A) sees markers of user B in a different way than others ( different color or marker image).

My idea is to create once a html file without markers and creat separate function which will be updateing map for every user separetly. I want to use Memecahce to dynamic update the map. If somebody add new marker, specific function shoudl add new marker without makeing and reolading whole map. I need that becouse application can have a lot of user with a lot of markers so it could be too expensive for server(reolading all markers after every update).

My question : How to change/add markers to map dynamicaly after creating a map file or maybe you have better idea to solve that problem.