Publications
201 results found
Marriott DA, Sloman M, Yialelis N, 1995, Management policy service for distributed systems, Departmental Technical Report: 95/10, Publisher: Department of Computing, Imperial College London
Mansouri-Samani M, Sloman M, 1995, GEM - A generalised event monitoring language for distributed systems, Departmental Technical Report: 95/8, Publisher: Department of Computing, Imperial College London
Event based monitoring is critical for managing and debugging networks and distributed systems. This paper presents GEM - an interpreted Generalised Event Monitoring language. It allows high level, abstract events to be specified in terms of combinations of lower level events from different nodes in a loosely coupled distributed system. Event monitoring components can thus be distributed within the system to perform filtering, correlation and notification of events close to where they occur and thus reduce network traffic. GEM is a declarative rule based language in which the notion of real time has been closely integrated and various temporal constraints can be specified for event composition. The paper discusses the effect of communication delays on composite event detection and presents a tree based solution for dealing with out-of-order event arrivals at event monitors.
Lupu E, Sloman M, 1995, An approach to role based management for distributed systems, Departmental Technical Report: 95/9, Publisher: Department of Computing, Imperial College London
Interpreting policy in automated managers facilitates the dynamic change of behaviour of a distributed management system by simply changing policies. This paper describes a management policy notation which can be used to define both authorisation policies (what activities a manager is permitted to do) and obligation policies (the activities a manager must perform). Some example policy specifications are given to demonstrate the notation and the concepts involved. A graphical policy editor is described which permits high level abstract policies to be refined into lower level, implementable policies and maintains derivation and dependency relationships between the different policies. A policy service which stores policies is outlined and its integration within a domain service for grouping policies is explained. Outlines are given of implementations of automated managers for interpreting obligation policies and of an access control mechanism for enforcing authorisation policies.
Sloman MS, 1995, Distributed Systems management: Configuration and Policy Issues, Object World UK, (London)
Sloman MS, 1995, Management Issues for Distributed Services, Proceedings IEEE 2nd International Workshop on Services in Distributed and Networked Environments (SDNE 95), Publisher: IEEE Computer Society Press, Pages: 52-59
Crane S, Dulay N, Fossa H, et al., 1995, Configuration Management for Distributed Software Services, Proceedings of IFIP/ IEEE International Symposium on Integrated Network Management (ISINM 95), Santa Barbara, Publisher: Chapman Hall, Pages: 29-42
Lupu EC, Sloman MS, Yialelis N, 1995, A Policy Based Role Framework for Access Control, First ACM/NIST Role Based Access Control Workshop (USA), Publisher: ACM Press
Sloman MS, 1994, Policy Driven Management for Distributed Systems, Journal of Network and Systems Management, Vol: 2, Pages: 333-360, ISSN: 1064-7570
Sloman MS, 1994, Domains: A Framework of Structuring Management Policy, Network and Distributed Systems Management, Publisher: Addison Wesley, Pages: 433-453
Sloman MS, 1994, Networks of Instruments, Concise Encyclopaedia of Measurements and Instrumentation, Publisher: Pergamon Press, Pages: 227-230
Marriott D, Mansouri-Samani M, Sloman MS, 1994, Specification of Management Policy, IFIP/IEEE Distributed Systems Operations & Management Workshop Toulouse (DSOM'94)
Moffett J, Sloman M, 1994, Policy Conflict Analysis in Distributed System Management, Journal of Organizational Computing, Vol: 4, Pages: 1-22, ISSN: 1532-7744
Mansouri-Samani M, Sloman MS, 1994, Monitoring Distributed Systems, Network and Distributed Systems Management, Publisher: Addison Wesley, Pages: 303-344
Sloman M, 1994, Network and Distributed Systems Management, Publisher: Addison Wesley, ISBN: 0-201-62745-0
Sloman MS, 1994, Management: What and Why, Network and Distributed Systems Management, Publisher: Addison Wesley, Pages: 3-13
MOFFETT J, SLOMAN M, 1993, POLICY HIERARCHIES FOR DISTRIBUTED SYSTEMS MANAGEMENT, IEEE J SEL AREA COMM, Vol: 11, Pages: 1404-1414, ISSN: 0733-8716
Distributed system management, involves monitoring the activity of a system, making management decisions and performing control actions to modify the behavior of the system. Most of the research on management has concentrated on management mechanisms related to Network Management or Operating Systems. However, in order to automate the management of very large distributed systems, it is necessary to be able to represent and manipulate management policy within the system. These objectives are typically set out in the form of general policies which require detailed interpretation by the system managers. This paper explores the refinement of general highlevel policies into a number of more specific policies to form a policy hierarchy in which each policy in the hierarchy represents, to its maker, his plans to meet his objectives and, to its subject, the objectives which he must plan to meet. Management action policies are introduced, and the distinction between imperatival and authority policies is made. The relationship of hierarchies of imperatival policies to responsibility, and to authority policies, is discussed. An outline approach to the provision of automated support for the analysis of policy hierarchies is provided, by means of a more formal definition of policy hierarchy refinement relationships in Prolog.
Moffett J, Sloman M, 1993, User and Mechanism Views of Distributed Systems Management, Distributed Systems Engineering Journal, Vol: 1, Pages: 37-47
Mansouri-Samani M, Sloman M, 1993, Monitoring Distributed Systems: A Functional Model of Monitoring in Terms of the Generation, Processing, Dissemination, and Presentation of Information can Help Determine the Facilities Needed to Design and Construct Distributed Systems., IEEE Network, Vol: 7, Pages: 20-30, ISSN: 0890-8044
- Cite
- Citations: 55
SLOMAN M, VARLEY B, MOFFETT J, et al., 1993, DOMAIN MANAGEMENT AND ACCOUNTING IN AN INTERNATIONAL CELLULAR NETWORK, 3RD INTERNATIONAL SYMP ON INTEGRATED NETWORK MANAGEMENT ( ISINM 93 ), Publisher: North Holland, Pages: 193-206
KRAMER J, MAGEE J, SLOMAN M, et al., 1992, CONFIGURING OBJECT-BASED DISTRIBUTED PROGRAMS IN REX, SOFTWARE ENG J, Vol: 7, Pages: 139-149, ISSN: 0268-6961
The popularity of the object-oriented programming paradigm has stimulated research into its use for parallel and distributed programming. The major issues that affect such use are concurrency control, object interfaces, binding and inheritance. In this paper, we discuss the relative merits of current solutions to these issues and describe an approach based on the use of active objects with essentially explicit interfaces and bindings, and composition as a pragmatic alternative to inheritance. The key feature of our approach is the use of a configuration language to define program structure as a set of objects and their bindings. The configuration language includes facilities for hierarchic definition of composite objects, parameterisation of objects, conditional configurations and recursive definition of objects. This separate and explicit description of program structure complements object-oriented programming. The approach is illustrated by examples from the REX environment for the development of parallel and distributed software.
Kramer J, Magee J, Sloman M, 1992, Configuring distributed systems., Publisher: ACM
Moffett JD, Sloman MS, 1991, The representation of policies as system objects, Pages: 171-184
This is an exploratory paper in which we describe: aspects of management policy which could be modelled as objects in a distributed computer system, in order to enable them to be queried and manipulated. Policies are 'the plans of an organisation to meet its goals'. They are persistent entities which are intended to influence actions, either by motivating actions or by authorising them. This distinction reflects the observation that agents only successfully carry out actions if they are both motivated and empowered to do so. In addition to persistence, policies have other main characteristics: they are directed to subjects; they aire typically organised in hierarchies in which the goal of a policy is achieved by creating lower-level policies until identifiable actions are completed; and policies may conflict, so they require to have a precedence ordering. There is a need to represent and manipulate policies, as objects within the computer system, so that they can be used to influence the activities of automated managers within large distributed computer systems. We describe a possible structure for policy objects and the operations which can be performed on them. Their attributes include: modality (positive or negative motivation or authorisation); policy subjects, goals, and target objects; and the constraints which may apply. The method of representation of relationships between policies is left as an open issue. Related work and concepts in the modelling of policies are referred to, including a brief discussion of security models in this context. The open issues raised by this paper are described.
Moffett JD, Sloman M, 1991, Content-Dependent Access Control., ACM SIGOPS Operating Systems Review, Vol: 25, Pages: 63-70
Kramer J, Sloman M, Magee J, 1991, Software Configuration Techniques In Operational Systems, Control and Dynamic Systems: Advances in Theory and Applications, Publisher: Academic Press, Pages: 325-356
Moffett J, Sloman M, 1991, DELEGATION OF AUTHORITY, 2ND INTERNATIONAL SYMP ON INTEGRATED NETWORK MANAGEMENT, Publisher: ELSEVIER SCIENCE PUBL B V, Pages: 595-606
SLOMAN M, 1991, USING DOMAINS FOR SPECIFYING MANAGEMENT POLICY, INTERNATIONAL WORKSHOP ON OPERATING SYSTEMS OF THE 1990S AND BEYOND : WHERE DO WE GO FROM HERE, Publisher: SPRINGER VERLAG, Pages: 25-30, ISSN: 0302-9743
Magee J, Kramer J, Sloman M, et al., 1990, An overview of the REX software architecture, Pages: 396-402
The authors describe the software architecture currently under development for the REX (Reconfigurable and Extensible Parallel and Distributed Systems) project, supported by the European Economic Community under the ESPRIT II initiative. The architecture is aimed at supporting the construction of reconfigurable and extensible parallel and distributed systems. The main principle underlying this architecture is that systems should be described, constructed, and modified as a structural configuration of interconnected component instances. The structure should be described by a separate explicit configuration language allowing components to be programmed in a range of heterogeneous programming languages. The authors give an informal description of the three elements of the architecture, namely, an interface specification language, a set of communication primitives, and a language for describing overall system structure, called Darwin. Examples of the use of these are given, together with an overview of how they integrate to support construction and reconfiguration of distributed systems.
MOFFETT J, SLOMAN M, TWIDLE K, 1990, Specifying discretionary access control policy for distributed systems, Computer Communications, Vol: 13, Pages: 571-580, ISSN: 0140-3664
This paper discusses a proposed framework for specifying access control policy for very large distributed processing systems. These typically consist of multiple interconnected networks and span the computer systems belonging to different organizations. This implies the need for cooperation between independent managers to specify access control policy. The policy specification should permit interaction between organizations while limiting the scope of what objects can be accessed and what operations can be performed on them. The large numbers of objects in such systems make it impractical to specify access control policy in terms of individual objects. The paper explains how domains can be used to group objects and structure the management of access control policy. Access rules are introduced as a means of specifying the access rights between a domain of user objects and a domain of target objects in terms of the permitted operations as well as constraints such as user location and time of day. The use of domains for specifying the scope for which authority can be delegated to managers or security administrators is explained and the issues related to implementing access rules using capabilities or access control lists are discussed.
Sloman M, Kramer J, Magee J, 1990, Configuration Support for System Description, Construction and Evolution, Managing Complexity in Software Engineering, Publisher: Peter Peregrinus, Pages: 247-260
Moffett JD, Sloman M, 1990, A Case Study in Representing a Model: to Z or not to Z?, Publisher: Springer, Pages: 254-268
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.