Patent ID: 6966058
Filing Date: 2005-11-15
Classification: G06F

Abstract:
1. A system for managing a software upgrade in a distributed computing system having a plurality of nodes that provides a plurality of fault-tolerant services, wherein a first set of nodes providing a first fault-tolerant service can differ from, yet can also overlap with, a second set of nodes providing a second service, and wherein making an upgrade current on a given node can take an amount of time sufficient to be considered a fault if not otherwise masked by fault-tolerance, the system comprising: at least one node which is communicatively connected to the plurality of nodes and which is configured to receive a software release, and to upgrade each of the plurality of nodes with the software release in a sequential manner, accounting for the possibility of different versions of software running on different nodes of the system, whereby the plurality of fault-tolerant services remain available while the software upgrade is in progress a service which is configured to notify the at least one node when a first copy of fault-tolerant service becomes unavailable; and wherein the at least one node is configured to assign a protected status to a node including any portion of a surviving copy of the fault-tolerant service, the protected status being effective to prevent the node from being upgraded.