Why randomize your file names for cloud storage/CDN?

Question

When you look at a profile picture on a social networking site like Twitter, they store image files like:

http://a1.twimg.com/profile_images/1082228637/a-smile_t         


        

Answer 1

Mainly, it prevents name collisions. More than one person might upload "IMG_0001.JPG", for example. You also avoid limits on the number of files in one directory, and you can shard images across multiple servers - there's no way a huge site like Twitter or Facebook could store all photos on one server, no matter how large.