Practical description of configurations for distributed systems management

The administration of distributed systems is an important practical problem. One of the significant parts of the problem is the management of software configurations. The size and complexity of distributed systems have made automation of software management tasks essential. The time has come to determine how to design systems with intrinsic features that enable general management. Experience with general approaches to software management is needed. This thesis presents a model that revolves around structured, declarative specifications of correct con figurations. It is possible to use declarative specifications to automatically check the cor rectness of a system and also to automatically fix various problems. The model relies on an abstract view of systems as collections of objects with particular attribute values. A new language is introduced for expressing configuration descriptions abstractly. Sim ple processing algorithms are given for automatically comparing a system with a descrip tion, and automatically eliminating discrepancies. A prototype implementation is described, and various related issues are explored. The proposed model and language are suitable for practical use, as is demonstrated by an experiment involving a production system. While further work is needed in a variety of areas, the feasibility of using declarative specifications according to a general, abstract model has been established. This approach is not of merely theoretical interest. It can be applied to common systems in routine use today.Science, Faculty ofComputer Science, Department ofGraduat