The Role of Operating Systems in Object-Oriented Distributed Multimedia Platforms

Considerable progress has been madein# the development of technologies tosupport# distributed multimedia computing, but applicationplatforms# are needed to make such technology accessible# to application programmers. This papersets# out requirements for such platforms and discusses the role of operating systems in object-oriented# platform support. We describe an initial approach to providing such a platform which attempted to factor out all realtime aspects of multimedia support ontoa# hardware based multimedia network interface unit. This solution has been partially successful but lacks the flexibility and level of integration subsequentlydemanded# by application programmers. Our response has been to redesign the multimedia network interface unit, placing more emphasis on the provision ofdynamic# services which require real-time operating system support. The new design described in this paper exploits and extends features of a distributed object-oriented micro-kernel to provide the n..

Single system image: A survey

Single system image is a computing paradigm where a number of distributed computing resources are aggregated and presented via an interface that maintains the illusion of interaction with a single system. This approach encompasses decades of research using a broad variety of techniques at varying levels of abstraction, from custom hardware and distributed hypervisors to specialized operating system kernels and user-level tools. Existing classification schemes for SSI technologies are reviewed, and an updated classification scheme is proposed. A survey of implementation techniques is provided along with relevant examples. Notable deployments are examined and insights gained from hands-on experience are summarized. Issues affecting the adoption of kernel-level SSI are identified and discussed in the context of technology adoption literature

Java operating systems: design and implementation

Journal ArticleLanguage-based extensible systems such as Java use type safety to provide memory safety in a single address space. Memory safety alone, however, is not sufficient to protect different applications from each other. such systems must support a process model that enables the control and management of computational resources. In particular, language-based extensible systems must support resource control mechanisms analogous to those in standard operating-systems. They must support the separation of processes and limit their use of resources, but still support safe and efficient interprocess communication

A File System Component Compiler

File System development is a difficult and time consuming task, the results of which are rarely portable across operating systems. Several proposals to improve the vnode interface to allow for more flexible file system design and implementation have been made in recent years, but none is used in practice because they require costly fundamental changes to kernel interfaces, only operating systems vendors can make those changes, are still non-portable, tend to degrade performance, and do not appear to provide immediate return on such an investment. This proposal advocates a language for describing file systems, called FiST. The associated translator can generate portable C code — kernel resident or not — that implements the described file system. No kernel source code is needed and no existing vnode interface must change. The performance of the file systems automatically generated by FiST can be within a few percent of comparable hand-written file systems. The main benefits to automation are that development and maintenance costs are greatly reduced, and that it becomes practical to prototype, implement, test, debug, and compose a vastly larger set of such file systems with different properties. The proposed thesis will describe the language and its translator, use it to implement a few file systems on more than one platform, and evaluate the performance of the automatically generated code

Quality of service management for non-guaranteed networks

The increasing dominance of multimedia communication posed new requirements for the underlying systems. Multimedia data, formally called continuous media, has time constraints that impose real time limitations for their transmission. Certain levels of service, called Quality of Service (QoS), need to be considered when handling continuous media. The present work utilizes QoS concepts for networks that do not have inherent QoS support. The thesis aims at verifying the possibility of having QoS-controlled communication on non-guaranteed networks. A basic QoS architecture is designed where already existing QoS concepts are adapted to work with non-guaranteed networks. The architecture provides the facilities of QoS specification, mapping, admission, maintenance, monitoring and notification. In addition, a new concept for predictive QoS admission is introduced. The proposed architecture was verified using a prototype system. The results showed an increased percentage of continuous media that arrive on time to their receivers (good put) with higher network loads. The increased good put was at the expense of high network overhead

Decentralising resource management in operating systems

This dissertation explores operating system mechanisms to allow resource-aware applications to be involved in the process of managing resources under the premise that these applications (1) potentially have some (implicit) notion of their future resource demands and (2) can adapt their resource demands. The general idea is to provide feedback to resource-aware applications so that they can proactively participate in the management of resources. This approach has the benefit that resource management policies can be removed from central entities and the operating system has only to provide mechanism. Furthermore, in contrast to centralised approaches, application specific features can be more easily exploited. To achieve this aim, I propose to deploy a microeconomic theory, namely congestion or shadow pricing, which has recently received attention for managing congestion in communication networks. Applications are charged based on the potential "damage" they cause to other consumers by using resources. Consumers interpret these congestion charges as feedback signals which they use to adjust their resource consumption. It can be shown theoretically that such a system with consumers merely acting in their own self-interest will converge to a social optimum. This dissertation focuses on the operating system mechanisms required to decentralise resource management this way. In particular it identifies four mechanisms: pricing & charging, credit accounting, resource usage accounting, and multiplexing. While the latter two are mechanisms generally required for the accurate management of resources, pricing & charging and credit accounting present novel mechanisms. It is argued that congestion prices are the correct economic model in this context and provide appropriate feedback to applications. The credit accounting mechanism is necessary to ensure the overall stability of the system by assigning value to credits

Modelling parallel database management systems for performance prediction

Abstract unavailable please refer to PD