Patent ID: 7698465

Claim:
A method for selecting a proposed command structure in a distributed computing system to synchronize execution of functions by a plurality of computing devices implementing the distributed computing system, the method comprising: transmitting a proposed command structure to a first quorum of devices in the distributed computing system, wherein the proposed command structure is a command structure that represents all equivalent sequence of functions, which is proposed for vote using an associated proposal number, the proposed command structure comprising one or more functions appended to a prefix, wherein the prefix is a smaller command structure from which the proposed command structure is derived; receiving acceptance messages indicating an acceptance of the proposed command structure by one or more devices that have accepted the proposed command structure, wherein an accepting device can send an acceptance message if it has not responded to a suggested proposal number higher than the proposal number and if it has previously voted for the prefix of the proposed command structure that was proposed using the proposal number or if it has not previously voted for any command structure proposed using the proposal number; and determining that the proposed command structure has been selected by the distributed computing system if the acceptance messages are received from a second quorum of devices.