Ticket Servers: Distributed Unique Primary Keys on the Cheap

A nice trick they use over at Flickr to get unique keys using a simple MySQL instance.

This prompts me again to muse about an infrastructure description language.

Octobot

Here's an interesting building block: a task queue processor. Runs anything in Java or other JVM languages. There's definitely a system-level design language waiting to be defined that would put together this sort of component to make an overall system.