Andrew D. Marshall

Services supporting management of distributed applications and systems

A distributed computing system consists of heterogeneous computing devices, communication networks, operating system services, and applications. As organisations move toward distributed computing environments, there will be a corresponding growth in distributed applications central to the enterprise. The design, development, and management of distributed applications presents many difficult challenges. As these systems grow to hundreds or even thousands of devices and similar or greater magnitude of software components, it will become increasingly difficult to manage them without appropriate support tools and frameworks. Further, the design and deployment of additional applications and services will be, at best, ad hoc without modelling tools and timely data on which to base design and configuration decisions. This paper presents a framework for management of distributed applications and systems. The framework is based on a set of common management services that support management activities. The services include monitoring, control, configuration, and data repository services. A prototype system built on the framework is described that implements and integrates management applications providing visualisation, fault location, performance monitoring and modelling, and configuration management. The prototype also demonstrates how various management services can be implemented.

Making distributed applications manageable through instrumentation

The goal of a management system in a distributed computing environment is to provide a centralized and coordinated view of an otherwise distributed and heterogeneous collection of hardware and software resources. Management systems monitor, analyse and control network resources, system resources, and distributed application programs. Many organizations currently depend on mission-critical distributed applications, a trend that will increase as software engineering tools emerge that make it easier to construct distributed applications. We believe that manageability must be built in to distributed applications from the beginning rather than added in an ad hoc fashion after they have been developed. Just as designing software for usability, testability and maintenance are being addressed in the development process, so must designing for manageability. Application manageability is a research issue of particular interest to us. The work described in this paper focuses on instrumenting processes to allow them to respond to management requests, generate management reports, and maintain information required by the management system. We present an instrumentation architecture to support this, a prototype implementation which includes a class library of standard instrumentation, and a methodology for instrumentation.

Policy-driven fault management in distributed systems

Management policies can be used to specify requirements about the desired behaviour of distributed systems. Violations of policies (faults) can then be detected, isolated, located and corrected using a policy-driven fault management system. Other work in this area to date has focused on network-level faults. We believe that in a distributed system it is more appropriate to focus on faults at the application level. Furthermore, this work has been largely domain-specific-a generic, structured approach to this problem is needed. Our work has focused on policy-driven fault management in distributed systems at the application level. In this paper, we define a generic architecture for policy-driven fault management and present a prototype system based on this architecture. We also discuss experience to date using and experimenting with our prototype system.

Configuration maintenance for distributed applications management

The MANDAS project has defined a layered architecture for the management of distributed applications. In this paper we examine a vertical slice of this architecture, namely the management applications and services related to configuration management. We introduce an information model which captures the configuration information for distributed applications and discuss a repository service based on the model. We define a set of services and management applications to support maintenance of configuration information, and describe how the different types of configuration information are collected. Finally, we present two management applications that use configuration information.

Fault Management in Distributed Systems: A Policy-Driven Approach

Managing the availability and performance of a distributed system involves monitoring the behavior of the system, identifying system problems, and correcting those problems. Each of these tasks requires some expertise, such as an understanding of the mechanics of the underlying system components. As the size and complexity of these systems increases, and the number of distributed applications executing on these systems increases, managing the availability and performance of distributed systems becomes more difficult. Little research has focused on embedding systems management expertise into a management application for a distributed system. In this paper we describe a rule-based management application for a commercially available distributed computing environment that is capable of monitoring the distributed system, detecting system service-related performance and availability problems, and generating corrective actions to correct the problems.

On the feasibility of ISO FTAM-based file servers to implement a heterogeneous file system

Abstract Networks of heterogeneous systems are becoming an increasingly important facet of distributed systems. A desirable service in such an environment is multiple file servers providing transparent access to files. Although easy to state, this problem is not easily solved. One approach to address this and other problems inherent in heterogeneous computing systems is through standardization. Results presented in this paper suggest that the International Organization for Standardizations File Transfer Access and Management (FTAM) standard provides a feasible and effective basis for file servers in a distributed file system.

Distributed Information Repository for Supporting Integrated Network Management

In our previous work, we have investigated the potential role and feasibility of using the X.500 Directory Service to store information collected from network management tools. The results suggested that the Directory could be used to store various types of management information, without it being the bottleneck in most management operations. This paper reports on an extension of that work. We introduce an architecture that centers the Directory Service as a management information repository in integrated network management. Two prototype implementations of the integrated network management architecture and the performance of the Directory Service are also described.