A connection management system can achieve scalability for domain computing among a plurality of domains. Each of the plurality of domains comprises a collection of machines and resources that are administrated as a unit. A connection concentrator can connect, and support communication between, a plurality of processes in a first domain and a plurality of processes in a second domain. The connection concentrator uses one connection to communicate with any one of the plurality of processes in the first domain, and can communicate with each one of the plurality of processes in the second domain.