Patent ID: 7539150

Claim:
A method, comprising: sending, from at least one node of a plurality of nodes of a network, a plurality of broadcast messages; discovering, by at least one other node of the plurality of nodes of the network, a node based on a received message; storing, by the at least one other node of the plurality of nodes of the network, an entry corresponding to the node and a corresponding timestamp that indicates a time at which the node was last discovered; and notifying, by the at least one node of the plurality of nodes of the network, that the node is offline, in response to determining that a predetermined time has elapsed since the corresponding timestamp was last updated, wherein the node is a selected node of the plurality of nodes, and wherein the method further comprises: (i) reading, by the at least one node of the plurality of nodes of the network, the selected node and a selected timestamp corresponding to the selected node from a routing table; (ii) determining, by the at least one node of the plurality of nodes of the network, whether the predetermined time has elapsed since the corresponding timestamp was last updated for the selected node in the routing table; and (iii) determining, by the at least one node of the plurality of nodes of the network, registered components that have registered to be informed on offline nodes, wherein the offline nodes are notified to the registered components; and (iv) removing, by the at least one node of the plurality of nodes of the network, the selected node from the routing table, in response to determining that the predetermined time has elapsed since the corresponding timestamp was last updated for the selected node in the routing table, wherein the plurality of nodes are included in a plurality of storage facilities, wherein the plurality of storage facilities includes primary and alternate image servers that comprise the plurality of nodes, wherein a domain group table includes correspondences between the primary and the alternate image servers, wherein the correspondences are indicative of a plurality of domain groups of the plurality of nodes, wherein an operational node of a selected domain group processes redirected messages that were generated for an offline node of the selected domain group, wherein the offline node is in a selected primary image server included in a selected storage facility and the operational node is a selected alternate image server included in the selected storage facility, and wherein the selected primary image server and the selected alternate image server belong to the selected domain group, and wherein the selected alternate image server stores backup data of the selected primary image server.