On-demand capacity management

A method for dynamically downsizing by one or more servers a network farm comprising a plurality of servers in response to diminished demand, the method comprising:

• identifying a routing policy for the network farm;
• statistically tracking information corresponding to demand upon a first one or more servers;
• determining from the tracked information that the network farm is capable of meeting current demand without the first one or more servers;
• and
• modifying configurable routing settings such that subsequent incoming messages are routed to a diminished set of second one or more servers of the network farm in response to determining from the tracked information that the network farm is capable of meeting current demand without the first one or more servers, the diminished set not including the first one or more servers,
• wherein modifying the configurable routing settings is performed using an application program interface provides a first interface that permits for immediate rerouting of incoming messages away from one or more servers of the network farm that are not in the diminished set and provides a second interface that permits rerouting of incoming messages with at least temporary continuance of routing of incoming messages that correspond to pre-existing stateful sessions to their pre-existing servers even if those pre-existing servers are no longer in the diminished set of server(s).

A computer program product comprising one or more computer readable devices having encoded thereon one or more computer-executable instructions that, when executed by one or more processors of a computing system, cause the computing system to provide an application program interface, the application program interface comprising:

• a reporting interface that is configured to report regarding one or more performance parameters of a network farm to thereby allow a user or other entity to determine when a network farm is reaching capacity, the reported performance parameters having been identified by identifying a routing policy for the network farm and statistically tracking information corresponding to the one or more performance parameters;
• an augmentation interface that is configured to allow for immediate rerouting of incoming application networks to an augmented network farm in the case where one or more servers are added to the network farm;
• and
• a diminution interface that is configured to allow for immediate rerouting of an incoming application message to a diminished network farm in the case where one or more servers are removed from the network farm, wherein the diminution interface comprises:
• an immediate diminution interface that causes all incoming application messages to be routed to the diminished network farm and causes all pending requests at the removed server(s) to be terminated;
• a graceful diminution interface that causes all incoming application messages to be routed to the diminished network farm, but allows at least some of the pending requests at the removed server(s) to be continued to completion;
• and
• a graceful diminution interface that allows some of the removed servers to temporarily continue serving incoming application messages that correspond to pre\-existing stateful sessions that they had been previously serving.