Most efficient way to store data on a linked server network

There are servers like Shotbow, McPVP, MineCade. How do they store all the information on all the servers they have. In the next 4 months I'll be creating a network of Minecraft servers custom coded, for example, CTF, KitPVP, Factions, Defend the Nexus, etc. I've tried to learn how some websites use JSON to record information in a URL, for example: https://www.api.website.com/bans/chris4315/notch/griefing/08042013

But I don't know how to do that. I have a MySQL database and that's what I've been using for my regular server right now, but I know that a JDBC connection itself is not too efficient. Any ideas?

 

Will the multiple minecraft servers be running on the same physical server machine or on different servers?
Anyway, I guess you could use a centralized MySQL server for all the minceraft servers. One MySQL server (eventually you could clone it to other servers) will be more efficient than using URL's (URL's have to be loaded by a webserver, which still uses MySQL)

About that URL: that's .htaccess rewriting (or in the case of nginx, this is done in the vhost config)
e.g.

Code:

RewriteRule /bans/([\w\d]*)/([\w\d]*)/([\w*)/(\d*) /index.php?view=bans&offender=%1&reporter=%2&conduct=%3&id=%4