In an ORC (object-orientedreal-timecomputing) environment, it is important to reduce message retransmissions during message passing because these retransmissions cause significant time delay. And, this makes it diff...
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ISBN:
(纸本)0769510892
In an ORC (object-orientedreal-timecomputing) environment, it is important to reduce message retransmissions during message passing because these retransmissions cause significant time delay. And, this makes it difficult to achieve the necessary timeliness. A cause of retransmission is message loss due to buffer overflow at the reception side. Here a P+I+D (P for proportional, I for integral and D for derivative) adaptive buffer control algorithm is proposed to prevent such possible overflow. The I control depends on the Convergence Algorithm (CA), which is a stable and efficient IEPM (Internet End-to-End Performance Measurement) toot that predicts the mean message roundtrip time (RTT) of a communication channel quickly and accurately,. The P+I+D algorithm was tested under different conditions in a mobile ORC (MORC) environment, where mobile agents collaborate freely over the Internet. The different test results confirm that the proposed P+I+D approach is indeed effective for preventing buffer overflow.
We discuss how to take checkpoints in object based systems. object based checkpoints are consistent in the object based system but may be inconsistent according to the traditional message based definition. We present ...
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This paper addresses the practical implementation of means of tolerating residual software faults in complex software systems, especially concurrent and distributed ones. There are several inherent difficulties in imp...
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ISBN:
(纸本)0769515584
This paper addresses the practical implementation of means of tolerating residual software faults in complex software systems, especially concurrent and distributed ones. There are several inherent difficulties in implementing such fault-tolerant software systems, including the controlled use of extra redundancy and the mixture of different design concerns. In an attempt to minimise these difficulties, we present a generic implementation approach, composed of a multi-layered reference architecture, a configuration method and an architectural pattern. We evaluate our implementation approach using an industrial control application whose control software we equip with the ability to tolerate a variety of software faults. The preliminary evidence shows that our approach can simplify the implementation process, reduce repetitive development effort and provide high flexibility through a generic interface for a wide range of fault tolerance schemes.
In this paper we present a new approach to distribute tasks connected by causal dependencies within a heterogeneous environment, e.g. several resources communicating with each other or a processor grid. Our approach u...
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Discusses a complex class of industrial applications involving co-operating multiple applications, each of which itself involves multiple processes. These applications normally work on multiple platforms with multiple...
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General-purpose middleware must often be specialized for resource-constrained, real-time and embedded systems to improve their response-times, reliability, memory footprint, and even power consumption. Software engine...
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distributedreal-time applications require flexible and dynamic scheduling mechanisms to provide timeliness guarantees to application objects. In this paper we present a new scheduling algorithm that exploits the task...
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Sensor webs are often composed of servers connected to distributedreal-time embedded (DRE) systems that operate in open environments where operating conditions, workload, resource availability, and connectivity canno...
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ISBN:
(纸本)9780769535739
Sensor webs are often composed of servers connected to distributedreal-time embedded (DRE) systems that operate in open environments where operating conditions, workload, resource availability, and connectivity cannot be accurately characterized a priori. The South East Alaska MOnitoring Network for Science, Telecommunications, Education, and Research (SEAMONSTER) project exhibits many common system management and dynamic operation challenges for effective, autonomous system adaptation in a representative sensor web. These challenges cover both field operation (e.g., power management through system sleep/wake cycles and reaction to local environmental changes) and server operation (e.g., system adaptation for new/modified goals, resource allocation for a changing set of applications, and configuration changes for fluctuating workload). This paper presents the results of integrating and applying quality-of-service (QoS)-enabled component middle-ware, dynamic resource management, and autonomous agent technologies to address these challenges in SEAMONSTER.
CSP is a fundamental concept for developing software for distributedrealtime systems. The CSP paradigm constitutes a natural addition to object orientation and offers higher order multithreading constructs. The CSP ...
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Conventional cache memories act to bridge the gap in speeds between the processor and main memory. However, typical cache memories do not take into account of the specific characteristics of objects-oriented programs....
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