Abstract: A service controller for providing centralized service management, control and placement, as well as guaranteed failover, in a dynamic and distributed computing environment. The service controller works in conjunction with a computing resource supply manager, which supplies the required resources so that the service controller can run the service on the allocated resources. The number of active service instances may dynamically increase or decrease in accordance with changing availability of or demand for resources. The service controller monitors the service instances and takes appropriate action in the event of service instance failures. The service controller is provided with a service director component, which records and tracks, for each service instance which has been started on a particular resource/host, the IP address of such host, through a name location service, thus allowing end-users to locate the service regardless of where the service instances are physically running.

Abstract: A service controller for providing centralized service management, control and placement, as well as guaranteed failover, in a dynamic and distributed computing environment. The service controller works in conjunction with a computing resource supply manager, which supplies the required resources so that the service controller can run the service on the allocated resources. The number of active service instances may dynamically increase or decrease in accordance with changing availability of or demand for resources. The service controller monitors the service instances and takes appropriate action in the event of service instance failures. The service controller is provided with a service director component, which records and tracks, for each service instance which has been started on a particular resource/host, the IP address of such host, through a name location service, thus allowing end-users to locate the service regardless of where the service instances are physically running.

Abstract: A server computer updates client computers' copies of subscription files stored on a network. The server computer retrieves a database record from a subscription database. The database record includes at least client computer and subscription file information. The server computer checks the subscription file stored on the network for any changes which may have occurred to the file since the previous checking of the subscription file preferably by comparing the last save time stamp to a time stamp on the subscription file stored on the network. If changes have occurred, the server computer creates an update file for the client computer and transmits the update file to the client computer, preferably by electronic mail. Each database record may further contain a check interval indicating the periodicity of the checking of the subscription file for changes. The database record may further contain a time last checked field which is updated each time the subscription file is checked for changes.