Distribution of content across servers?

Question

rsync

Hello!
At the moment, there are 2 servers.
On one database, on the second nginx + scripts + files (mostly images).
What is the best way to distribute file downloads across multiple servers? Since the place will soon approach zero and I would like to distribute the files to one server, the database to another, the executable scripts to another))
There is one of the options:
1. The file is uploaded to the main server
2. Based on the statistics in the database, determine which server send an image
3. Set up rsync
+ to this, add a server for balancing + a couple of servers for executing scripts, so that there is somewhere to transfer it under load.
I looked at options with clouds, but because pictures are often pulled, then the traffic is not very cheap + self-storage.