Most eligible server in a common work queue environment

A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for managing a plurality of servers, said method steps comprising:

• providing a shared queue;
• providing a plurality of servers each operable to determine whether it has capacity to process a message, and if determined to have the capacity, further operable to dequeue a message in the shared queue, process the message and place one or more response messages in the shared queue;
• using at least one client to transmit messages to the shared queue and to receive messages in the shared queue from the plurality of servers;
• establishing a list having a most eligible server status record accessible by said client, the most eligible server status record being updated when one or more of the plurality of servers connects to the shared queue and determines that its eligibility to process requests is greater than is currently reflected in the most eligible server status record, the most eligible server status record further being updated when one or more of the plurality of servers disconnects from the shared queue;
• and
• providing a processor for maintaining the list further indicating whether at least one of the plurality of servers is eligible and available to process a particular message from the at least one client, the list further indicating one or more types of messages eligible to be processed by said at least one of the plurality of servers, said at least one client checking the list before transmitting said particular message to the shared queue to determine if a server is available to process said particular message, said at least one client enqueuing said particular message in the shared queue only if it is determined that a server is available,
• if there is a change in the most eligible server status record, notifying the client of the change, and if the most eligible server status record is lower than its previous status, providing the client an option of removing one or more requests from the shared queue for which there is no longer a server eligible to process.

A data processing system comprising:

• a common queue;
• a plurality of servers for processing messages of different types, each operable to determine whether it has capacity to process a message, and if determined to have the capacity, further operable to dequeue a message in the common queue, process the message and place one or more response messages in the common queue;
• at least one client for transmitting messages to the common queue and receiving messages in the common queue from the plurality of servers;
• a list having a most eligible server status record accessible by said client the most eligible server status record being updated when one or more of the plurality of servers connects to the shared queue and determines that its eligibility to process requests is greater than is currently reflected in the most eligible server status record, the most eligible server status record further being updated when one or more of the plurality of servers disconnects from the shared queue;
• and
• processor means for maintaining the list further indicating whether, for each of the different types of messages, at least one of the plurality of servers is eligible and available to process said each of the different types of messages, the list further indicating one or more types of messages eligible to be processed by said at least one of the plurality of servers, said at least one client checking the list before transmitting a particular message to the common queue to determine if a server is available to process said particular message, said at least one client enqueuing said particular message in the common queue only if it is determined that a server is available,
• wherein if there is a change in the most eligible server status record, the client is notified of the change, and if the most eligible server status record is lower than its previous status, the client is provided with an option of removing one or more requests from the shared queue for which there is no longer a server eligible to process.