Patent ID: 7466662
Filing Date: 2008-12-16
Classification: H04L

Abstract:
1. At a current node in a federation infrastructure, a method for discovering liveness information for another node in the federation infrastructure, the method comprising: an act of receiving a message from a sending node, the message including at least one liveness header representing state information for a participating node in the federation infrastructure, the state information including at least a participating node ID, an instance ID, a phase value, and a freshness value, the instance ID identifying an instance of the participating node, the phase value identifying an expressed phase of the participating node, the phase value including an expressed phase-state value and a phase.unknown indication, the phase-unknown indication indicating if the phase-state value was actually known to the sending node at the time indicated by the freshness value, the freshness value indicating how recently the instance ID and phase value where identified; an act of accessing at least a current instance ID, current phase value, and current freshness value for the participating node maintained at the current node; an act of comparing at least the received instance ID, the received phase value, and the received freshness value to the current instance ID, the current phase value, and the current freshness value respectively at a current node; and an act of determining if state information for the participating node is to be updated at the current node based on the comparison.