Patent ID: 8560662

Claim:
At an update computing device, said update computing device connected to a plurality of other computing devices arranged in a computer cluster, said update computing device configured to perform a maintenance operation to update said plurality of other computing devices in a specified manner, at least one further update computing device configured to perform a different maintenance operation to update said plurality of computing devices in a different specified manner, a method for updating at least a subset of computing devices selected from among said plurality of computing devices, said method comprising: identifying at least a subset of computing devices, selected from among said plurality of computing devices, that are to be updated in said specified manner; for each computing device in said at least a subset of computing devices, locking said computing device for performance of said maintenance operation, including: creating a persistent object at said computing device, said persistent object including at least an identifier, said identifier identifying the update computing device as owner of the persistent object, presence of the persistent object communicating to the at least one further update computing device that said computing device is locked for updating in said specified manner; subsequent to locking each computing device in said at least a subset of computing devices, updating each computing device in said at least a subset of computing devices in said specified manner, including for each computing device: searching for persistent objects at said computing device; determining that said persistent object is present at said computing device; accessing said identifier included in said persistent object; determining that said identifier identifies said update computing device as said owner of said persistent object, the determination being indicative of the computing device be locked for update in the specified manner; and performing said maintenance operation at said computing device to update said computing device in said specified manner.