Abstract: A data communication network having a plurality of nodes interconnected with a communication link, wherein each node shares given ones of its data sets in common with other nodes in the network, and each node is operative to update any shared data set, except if one of the other nodes is also seeking to update the same data set, in which case the node having the higher priority prevails. Each node has a memory which stores the node location of each shared data set and the updating priority which each node has with respect to each respective set of shared data. A node receiving competing requests for update will access this memory and, depending upon the sequence of the requests, may accept a higher priority request and refuse a lower priority request.