Scheduling computerized backup services

An apparatus for scheduling a backup service in a computer installation having a plurality of clients consisting of more than one client type, a plurality of interconnected networks and at least one server, comprising:

• (a) a Modeler which calculates utilization of computer installation resources and elapsed time for the selected service for a selected subset of clients, the calculations using definitions of client types, network types and interconnection of clients and networks in the computer installation, using queues to model elements in the installation which work to provide the services and using Little's Law to calculate throughput;
• and
• (b) a Scheduler which repeatedly invokes the Modeler with subsets of clients to find utilizations and elapsed times and adjusts the subsets to generate a schedule which is a list of subsets of clients which can be serviced sequentially without exceeding a utilization criterion or an elapsed time criterion.

An apparatus for scheduling services in a computer installation having a plurality of clients consisting of more than one client type, a plurality of interconnected networks and at least one server, comprising:

• (a) first means for modeling utilization of the computer installation resources for services for a selected subset of clients, which calculates utilization of installation resources using definitions of client types, network types and interconnection of clients and networks in the computer installation;
• (b) second means for modeling which calculates elapsed time for the selected service for a selected subset of clients using Little's Law to calculate throughput;
• (c) means for scheduling which repeatedly invokes the first and second means for modeling with subsets of clients to find utilizations and elapsed times for the subsets and adjusts the subsets to generate a schedule which is a list of subsets of clients which can be serviced sequentially without exceeding a utilization criterion or an elapsed time criterion.

The apparatus of claim 7 wherein the service being scheduled is a backup service.

A computer readable storage device containing program code for scheduling a selected service in a computer installation having a plurality of clients consisting of more than one client type, a plurality of interconnected networks and at least one server, the program code comprising:

• (a) program code for modeling utilization of the computer installation resources and elapsed time for the selected service for a selected subset of clients uses Little's Law to calculate throughout, the modeling using definitions of client types, network types and interconnection of clients and networks in the computer installation;
• and
• (b) program code for scheduling which repeatedly invokes the program code for modeling with subsets of clients to find utilizations and elapsed times and adjusts the subsets to generate a schedule which is a list of subsets of clients which can be serviced sequentially without exceeding a utilization criterion or an elapsed time criterion.