Abstract: In a computer system having multiple servers, services are coordinated among nodes as a result of each node tracking the node state of each other node (such as the services it currently performs) and performing coordinator functions (such as controlling which servers provide which services) only if it determines itself to be a coordinator node and only if all nodes are in agreement as to the node state of every node. Each node communicates, to each of the other nodes, its node state, a coordinator node identifier indicating which node it has determined to be the coordinator node, and a global state of all nodes it determines based on the node states and coordinator nodes of all the nodes. A node performs coordinator functions only if it is a coordinator node and only if all nodes have the same global state.

Abstract: In a computer system having multiple servers, services are coordinated among nodes as a result of each node tracking the node state of each other node (such as the services it currently performs) and performing coordinator functions (such as controlling which servers provide which services) only if it determines itself to be a coordinator node and only if all nodes are in agreement as to the node state of every node. Each node communicates, to each of the other nodes, its node state, a coordinator node identifier indicating which node it has determined to be the coordinator node, and a global state of all nodes it determines based on the node states and coordinator nodes of all the nodes. A node performs coordinator functions only if it is a coordinator node and only if all nodes have the same global state.

Abstract: A system, method and computer program to detect and recover from a communications failure in a computer network. The computer network has several nodes which include processor-based systems, input/output controllers and network controllers. Each node has a cluster adapter connected to multiple port switches through communications links. Data is transmitted through among the nodes through the communications links in the form of packets. A fabric manager module will monitor the network and detect a link failure. Upon the detection of a link failure between two switches a spanning tree partitioning module will partition the network into two trees at the point of the link failure. Thereafter, a link and switch identification module will identify a link between the two trees that can replace the failed link and has the least impact on the network. A routing table calculation algorithm module will calculate a new routing and distance table based on the identified link.