this paper provides a series of lessons learned with respect to using performance modeling and analysis techniques on designs of object-oriented software systems. Specifically it focuses on the application of the Unif...
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For distributedreal-time systems, adequate profiling tools are exceedingly rare. the sheer variety and low-level nature of these systems impede the adoption of standard, general-purpose tools for performance analysis...
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ISBN:
(纸本)076952561X
For distributedreal-time systems, adequate profiling tools are exceedingly rare. the sheer variety and low-level nature of these systems impede the adoption of standard, general-purpose tools for performance analysis and visualization. Although much research has been devoted to profiling parallel clusters and supercomputers, the literature virtually ignores the real-time domain. Correspondingly, a handful of commercial tools is available for profiling realtime software, but they invariably make a single-node assumption and are unable to cope withdistributed environments. We examine the state of performance analysis and discuss why profilers are conspicuously absent in the field of distributedreal-time systems. We then explore how developers of these systems could benefit from graphical profiling tools with automatic instrumentation and data collection. Toward that end, we demonstrate the prototype of a performance visualization tool called "Bacara," the second addition to our suite of tools for Visual Analysis of distributedreal-time systems, or VADR (va'dar).
Guaranteeing response times of real-time (RT) distributedcomputing systems has been recognized as one of the biggest challenges by the RT software research community for three decades. the concept of a hybrid approac...
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ISBN:
(纸本)076952561X
Guaranteeing response times of real-time (RT) distributedcomputing systems has been recognized as one of the biggest challenges by the RT software research community for three decades. the concept of a hybrid approach that combines analytical derivation approaches and testing-based statistical derivation approaches in a symbiotic form for meeting this challenge was presented in recent years. However, concrete practical hybrid approaches are still in early stages of development. One such approach pursued by the authors and their collaborators is presented here. this paper focuses on the cases of deriving tight execution time bounds of the segments of object methods which do not involve calls for services from the operating system kernel and middleware. A case-study that demonstrates how the adopted approach works in handling a simple practical application is also presented.
distributedreal-timecomputing is one of the enabling technologies in establishing a team of autonomous robots. A team of soccer playing robots, Paderkicker, contains many computing nodes handling environment percept...
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To handle the extreme situation that must manage positional information of a very large volume, at least millions, of moving objects, a cluster-based scalable distributedcomputing system architecture, called the GALI...
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ISBN:
(纸本)076952561X
To handle the extreme situation that must manage positional information of a very large volume, at least millions, of moving objects, a cluster-based scalable distributedcomputing system architecture, called the GALIS, which consists of multiple data processors, each dedicated to keeping records relevant to a different geographical zone and a different time zone, was proposed In this paper, we propose a valid time management and time-zone shifting scheme, which are essential in realizing the long-term location data subsystem of GALIS, but missed in our previous prototype development. We explain how to manage valid time of moving objects to avoid ambiguity of location information. We also describe time-zone shifting algorithm, withthree variations, such as RT-TZS, B-TZS and TPB-TZS. through experiments related with query processing time and CPU utilization, we show the efficiency of the proposed time-zone shifting schemes.
this paper presents the evaluation of a multithread distributedreal-timeobject-oriented platform. A communication API was developed to increase functionalities of an API that implements the real-time Specification f...
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this paper tackles the problem of ever changing embedded systems non-functional requirements, specially the architectural ones. It proposes a solution based on Features Model and MDA standards, which is called Feature...
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ISBN:
(纸本)076952561X
this paper tackles the problem of ever changing embedded systems non-functional requirements, specially the architectural ones. It proposes a solution based on Features Model and MDA standards, which is called Features-oriented Model-Driven Architecture (FOMDA). this proposal can be used to help application designer in defining the mappings and transformations of UML models to as many target platforms as wished. this is done by configuring model-to-model and model-to-code transformations over tiers, where every tier represents some target platform properties that the system must be mapped and transformed to. To validate the proposal a case study related to the development of an embedded real-time system is presented, detailing how to transform a generic high-level UML model to a model specific for a given target platform. Obtained results are optimistic and conclude that the FOMDA approach can make designers re-think their current development process to make it more decoupled from a specific target platform.
Service overlays that support distributed stream processing applications are increasingly being deployed in wide-area environments. the inherent heterogeneous, dynamic and large-scale nature of these systems makes it ...
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ISBN:
(纸本)076952561X
Service overlays that support distributed stream processing applications are increasingly being deployed in wide-area environments. the inherent heterogeneous, dynamic and large-scale nature of these systems makes it difficult to meet the Quality of Service (QoS) requirements of the distributed stream processing applications. In this paper we address the load balancing problem for distributed stream processing applications and present a decentralized and adaptive algorithm that allows the composition of distributed stream processing applications on the fly across a large-scale system, while satisfying their QoS demands. the algorithm fairly distributes the load on the resources and adapts dynamically to changes in the resource utilization or the QoS requirements of the applications. Our experimental results demonstrate the scalability, efficiency and performance of our approach.
the development of safety critical software applications has always been done in accordance to strict methods. these systems require the application of verification techniques that guarantee safety properties. Often, ...
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ISBN:
(纸本)076952561X
the development of safety critical software applications has always been done in accordance to strict methods. these systems require the application of verification techniques that guarantee safety properties. Often, they are complex systems that require the integration of different types of engineers such as safety engineers and software architects. Currently, different groups of engineers apply different analysis and modeling techniques (e.g. architectural description languages, and safety analysis models);these differences create inconsistencies between different types of model. In this paper we introduce some solutions to reduce these problems in some safety architectures. these solutions integrate developing modeling languages such as UML and specific safely analysis languages such as FTA and FMECA.
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.
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