Patent ID: 8199668

Claim:
A method for an application instance to request attachment to a queue, the method comprising: an application instance requesting attachment to a particular queue partition of a set of queue partitions, the particular queue partition residing on a messaging server within a plurality of messaging servers, each of the plurality of messaging servers holding at least one queue partition to form the set of queue partitions, the set of queue partitions together forming a single queue, the request requesting exclusivity with regard to other application instances based on a common identifier in the request used by the requesting application instance, wherein exclusivity is only requested while the attach request is being processed by the messaging server on which the queue partition resides; receiving an indication whether the request for exclusivity can be fulfilled in response to requesting attachment; responsive to an indication that the request for exclusivity can be fulfilled, attaching to the particular queue partition; responsive to an indication that the request for exclusivity cannot be fulfilled by the particular queue partition, repeating the request for exclusivity to at least one other queue partition within the set of queue partitions until either one of the queue partitions indicate the request can be fulfilled or all queue partitions have indicated they are unable to fulfil the request; when all queue partitions of the set of queue partitions are unable to fulfil the request for exclusivity, the application instance requesting, of at least one queue partition of the set of queue partitions, a non-exclusive attachment without regard for other application instances of the same application as the requesting application instance, and attaching to a queue partition indicating it can fulfil the request for non-exclusive attachment.