On the number of active nodes in a multicomputer system

In this article we develop probabilistic algorithms for estimating the number of active nodes in a multicomputer system which consists of independent computers that are interconnected by a communication network. The algorithms are based on routine exchange of messages among the nodes of the multicomputer. using random routing. We show that each active node can find an €-estimate of the fraction A of active nodes in the system in time that depends only on E and A . The underlying approach can be used for finding various global properties of distributed systems with decentralized control.