Justin Warren of eigenmagic comments:
The centralised command-and-control method doesn’t work at scale. Many people have discovered this independently, from the Romans to the Chinese. It’s just not humanly- (or even computerly-) possible to track that many interdependent variables and make smart decisions.
To manage a vast array of components, a central apparatus needs to understand every detail of the entire whole. You need to direct every single peasant about how many shoes to make, or what to plant (and when! and when to fertilise! and when to harvest!) and if you don’t get it all right, the entire system collapses under its own weight.
Justin takes a very interesting approach to ACI in this post. The theoretical background is very interesting.
Read more at: Cisco ACI and Lossy Control