Embedded systems are complex as a whole but consist of smaller independent modules interacting with each other. This structure makes them amenable to compositional design. real-time embedded systems consist of realtim...
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Embedded systems are complex as a whole but consist of smaller independent modules interacting with each other. This structure makes them amenable to compositional design. real-time embedded systems consist of realtime workloads having deadlines. Compositional design of such systems can be done using real-timecomponents arranged in a scheduling hierarchy. Each component consists of some real-time workload and a scheduling policy for the workload. To simplify schedulability analysis for such systems, analysis should be done compositionally using interfaces that abstract timing requirement of components. To facilitate analysis of dynamically changing systems, the framework should also support incremental analysis. In this paper, we overview our approach to compositional and incremental schedulability analysis of hierarchical real-time systems. We describe a compositional analysis technique that abstracts resource requirement of components using periodic resource models. To support incremental analysis and resource bandwidth minimization, we describe an extension to this interface model. Each extended interface consists of multiple periodic resource models for different periods. This allows the selection of a periodic model that can schedule the system using minimum bandwidth. We also account for context switch overhead of components in these extended interfaces. We then describe an associative composition technique for such interfaces, that supports incremental analysis
The overall objective of the XtreemOS project is the design, implementation, evaluation and distribution of an open source grid operating system (named XtreemOS) with native support for virtual organizations (VO) and ...
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The overall objective of the XtreemOS project is the design, implementation, evaluation and distribution of an open source grid operating system (named XtreemOS) with native support for virtual organizations (VO) and capable of running on a wide range of underlying platforms, from clusters to mobiles. The approach we propose is to investigate the design of a grid OS, XtreemOS, based on the Linux existing general purpose OS. A set of system services, extending those found in the traditional Linux, will provide users with all the grid capabilities associated with current grid middleware, but fully integrated into the OS. The underlying Linux will be extended as needed to support VOs spanning across many machines and to provide appropriate interfaces to the Grid OS services. Installed on each participating machine, the XtreemOS system will provide for the grid what an operating system offers for a single computer: abstraction from the hardware, and secure resource sharing between different users. It would thus considerably ease the work of users belonging to VOs by giving them (as far as possible) the illusion of using a traditional computer, and releasing them from dealing with the complex resource management issues of a grid environment. By integrating grid capabilities into the kernel, XtreemOS will also provide a robust, secure and easy to manage infrastructure for system administrators
Simulation and analysis are computational techniques evaluating dynamic features of the component in design. Multi-disciplinary simulation is advocated to guarantee high fidelity simulating of the real state of workin...
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Simulation and analysis are computational techniques evaluating dynamic features of the component in design. Multi-disciplinary simulation is advocated to guarantee high fidelity simulating of the real state of working. The interoperability and reusability of simulation models in distributed heterogeneous environment are the inherent requirement for the analysis of complex product which is designed by geographically distributed teams in a process of great complexity. The serviceorientedcomputing(SOC) is emerging as a new paradigm of software system for distributed application. We propose a multi-disciplinary simulation environment based SOC. The process of work and the computing resources are defined, registered, consumed and orchestrated services. We address several key issues in this analysis environment and study a typical case based on a prototype system. The new paradigm leverages available engineering resources embodied as loosely-coupled services. serviceorientedcomputing has great potential in engineering application.
The proceedings contain 68 papers. The topics discussed include: getting more flexible scheduling in the RTSJ;automatic memory management in utility accrual scheduling environments;a hybrid scheduling scheme for hard,...
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ISBN:
(纸本)076952561X
The proceedings contain 68 papers. The topics discussed include: getting more flexible scheduling in the RTSJ;automatic memory management in utility accrual scheduling environments;a hybrid scheduling scheme for hard, soft and non-real-time tasks;scheduling non-preemptive periodic tasks in soft real-time systems using fuzzy inference;load balancing techniques for distributed stream processing applications in overlay environments;MDA-based development in the DECOS integrated architecture-modeling the hardware platform;looking ahead in open multithreaded transactions;a space-efficient caching mechanism for flash-memory address translation;java framework for distributedreal-time embedded systems;a software enhancement system for embedded software development;integrated scheduling with garbage collection for real-time embedded applications in CLI;and embedded sensor networked operating system.
The following topics are dealt with: scheduling and resource management; system design; embedded systems; software design; wireless and sensor networks; industrial advances; middleware; systems modeling; UML; distribu...
The following topics are dealt with: scheduling and resource management; system design; embedded systems; software design; wireless and sensor networks; industrial advances; middleware; systems modeling; UML; distributedreal-timecomputing; language support and design patterns; data communication; fault-tolerance and security; and performance evaluation
Long-running MPI applications on clusters and grids that are prone to node and network failures, motivates the use of fault tolerant MPI implementations. However, previous fault tolerant MPIs lack the ability to allow...
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Long-running MPI applications on clusters and grids that are prone to node and network failures, motivates the use of fault tolerant MPI implementations. However, previous fault tolerant MPIs lack the ability to allow the user to easily choose appropriate fault recovery strategies according to the execution environment, independent of the application codes-rather, the user often had to hard-code restoration strategies in accordance to diverse sets of fault patterns, which could be numerous: for instance, if the fault is transient to a particular process, we merely have to restart the process on the same computing node; on the other hand, if the fault is due to repetitive hardware unreliability, we must migrate the process to a new node in its recovery. ABARIS is our new fault/recovery model aware component framework for MPI, where users can customize MPI fault detection and recovery algorithms according to their application and execution environmental requirements by merely selecting appropriate fault/recovery components, independent of the application code. Currently, the ARABIS framework prototype is implemented on top of MPICH-P4MPD. Preliminary evaluation of the prototype using NPB on our MPI fault simulator demonstrates that overhead compared to the original MPICH-P4MPD is almost negligible (less than 1%) under normal execution, and when faults occur, appropriate selections and pairings of fault model and recovery method components for corresponding to the execution environment is significant to the overall execution time.
Copyright and Reprint Permissions: Abstracting is permitted with credit to the source. Libraries may photocopy beyond the limits of US copyright law, for private use of patrons, those articles in this volume that carr...
Copyright and Reprint Permissions: Abstracting is permitted with credit to the source. Libraries may photocopy beyond the limits of US copyright law, for private use of patrons, those articles in this volume that carry a code at the bottom of the first page, provided that the per-copy fee indicated in the code is paid through the Copyright Clearance Center. The papers in this book comprise the proceedings of the meeting mentioned on the cover and title page. They reflect the authors' opinions and, in the interests of timely dissemination, are published as presented and without change. Their inclusion in this publication does not necessarily constitute endorsement by the editors or the Institute of Electrical and Electronics Engineers, Inc.
In a real-timedistributedcomputing environment, security is critical to protect the system from unauthorized access especially since such systems are being used in time critical applications. Access Control mechanis...
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ISBN:
(纸本)076952561X
In a real-timedistributedcomputing environment, security is critical to protect the system from unauthorized access especially since such systems are being used in time critical applications. Access Control mechanisms have been introduced during the last several decades and have offered a basic and powerful means for enforcing security. In this paper, we examine the concepts of the TMO (time Triggered Message Triggered object) scheme that provides guaranteed real-timeservices in a distributedobjectcomputing environment. We also examine access control mechanisms;such as the traditional model, the RBAC (Role-based Access Control) model and the UCON (Usage Control) model. The main contribution of this paper is applying the traditional, RBAC and UCON models to the TMO scheme in order to provide a secure real-timedistributed environment.
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