I am developing a website that uses Google Maps.
The map has 4000-5000 markers.
Upon the client enters the website the server determines all "active" markers and sends a JSON document telling the client information about each marker and what marker-icon to use (a url to an image on the server, ex: icon: '/icon/xxx.png').
The website loads instantly but it takes about 5 seconds until all markers are shown since the client has to fetch those ~5000 images.
The images can change so the server only knows when the client ask for it, exactly which image each marker uses.
How can I speedup this process?
Can I dynamically create a spritesheet of some sort or pack all those files and let the client unpack them for faster loading?
The server backend is PHP för this part.