On the complexity of simple distributed systems

Computer systems that consist of millions of nodes, span the entire Internet, change continuously, and are managed by many different people and organizations. These types of systems have a natural habit of exhibiting exceedingly complex behavior, yet keeping their design simple is crucial. Various research groups started concentrating on computer systems that qualify as self-managing, self-organizing, self-healing, and so forth. Perhaps the most intriguing aspect of these self- systems is that they're designed to exhibit behavior. This behavior is often called complex.