This paper describes an extension to the component-based programming model to support real-time dynamic guarantee for distributed applications. The extended model aims to include an acceptance tests to component-based...
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This paper describes an extension to the component-based programming model to support real-time dynamic guarantee for distributed applications. The extended model aims to include an acceptance tests to component-based servers at bind time. We present the mapping of our model to the CORBA component Model, the architecture to support the dynamic guarantee in component-based middleware, the implementation of this architecture in CIAO (component Integrated ACE ORB) and the result of experiments run to evaluate the cost of the mechanisms used
Standards-based quality of service (QoS)-enabled component middleware is increasingly being used as a platform for developing distributedreal-time embedded (DRE) systems that execute in open environments where operat...
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Standards-based quality of service (QoS)-enabled component middleware is increasingly being used as a platform for developing distributedreal-time embedded (DRE) systems that execute in open environments where operational conditions, input workload, and resource availability cannot be characterized accurately a priori. Although QoS-enabled component middleware offers many desirable features, until recently it lacked the ability to efficiently allocate resources and configure platform-specific QoS settings based on utilization of system resources and application QoS. Moreover, it has also lacked the ability to monitor and enforce application QoS requirements. This paper presents two contributions to research on adaptive resource management for component-based DRE systems. First, we describe the structure and functionality of the resource allocation and control engine (RACE), which is an open-source adaptive resource management framework built atop standards-based QoS-enabled component middleware. Second, we demonstrate the effectiveness of RACE in the context of a representative DRE system: NASA's magneto spheric multi-scale mission system
Requirements of high integrity systems now encompass distribution mechanisms along with strong functional and non-functional features (run-time support for hardware, dependability, safety, analyzability). In this pape...
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Requirements of high integrity systems now encompass distribution mechanisms along with strong functional and non-functional features (run-time support for hardware, dependability, safety, analyzability). In this paper, we show how model processing help addressing such needs. We present a generic distribution model suitable for high integrity systems, and demonstrate how a high-level modeling deployment view allows one to greatly reduce the model complexity. Finally, we conclude by assessing a case study
It is usually infeasible to test distributed systems and protocols for dependability, fault-tolerance and performance in the real operation environment. This is attributed to the cost of setting up the hosting distrib...
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It is usually infeasible to test distributed systems and protocols for dependability, fault-tolerance and performance in the real operation environment. This is attributed to the cost of setting up the hosting distributed environment and the difficulty of controlling such a dynamic environment. The factors are too many and are very dynamic. This paper presents the wide area network emulator for CORBA applications: a general purpose software tool that emulates a distributed networked environment for CORBA middleware and applications and gives the user full control over the emulation environment in addition to the ability to inject network-related faults
In the last decade, the size and complexity of the software in embedded systems have increased. The present study attempts to decrease the complexity and difficulty of software development in embedded systems. We here...
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In the last decade, the size and complexity of the software in embedded systems have increased. The present study attempts to decrease the complexity and difficulty of software development in embedded systems. We herein introduce a new component system that is suitable for embedded systems. It is possible to estimate the memory consumption of an entire application since the proposed system adopts a static configuration. In addition, this system takes into account to be used in several domains of embedded systems because several particle sizes of component are supported. Moreover, the concept of the component for a distributed application is presented
Increasingly the need for protecting information from unauthorized access has lead to more attention in the field of information security. Access control mechanisms have been in place for the last four decades and are...
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Increasingly the need for protecting information from unauthorized access has lead to more attention in the field of information security. Access control mechanisms have been in place for the last four decades and are a powerful tool utilized to ensure security. In a real-timedistributedcomputing environment, systems have to meet timing constraints for time sensitive applications, such as obtaining financial quotes and operating command and control systems. However, real-timedistributedcomputing environment security is yet to be investigated. Earlier work examined a time Triggered Message Triggered object (TMO) scheme that provides real-timeservices in a distributedcomputing environment secured by applying a Role-Based Access Control (RBAC). In this paper we describe the application of a sophisticated Usage Control (UCON) model for a TMO and subsequently design an application that utilizes a Coordinated Anti-Missile Interceptor Network (CAMIN) system. This application is a secure CAMIN based upon a secure TMO that applies a realtime UCON (RT-UCON) in the CAMIN environment
Today component- and service-based technologies play a central role in many aspects of enterprise computing. However, although the technologies used to define, implement, and assemble components have improved signific...
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Today component- and service-based technologies play a central role in many aspects of enterprise computing. However, although the technologies used to define, implement, and assemble components have improved significantly over recent years, techniques for verifying systems created from them have changed very little. The correctness and reliability of component-based systems are still usually checked using the traditional testing techniques that were in use before components and services became widespread, and the associated costs and overheads still remain high. This paper presents an approach that addresses this problem by making the system verification process more component-oriented. Based on the notion of built-in tests (BIT)-tests that are packaged and distributed with prefabricated, off-the-shelf components-the approach partially automates the testing process, thereby reducing the level of effort needed to establish the acceptability of the system. The approach consists of a method that defines how components should be written to support and make use of run-time tests, and a resource-aware infrastructure that arranges for tests to be executed when they have a minimal impact on the delivery of system services. After providing an introduction to the principles behind component-based verification and explaining the main features of the approach and its supporting infrastructure, we show by means of a case study how it can reduce system verification effort.
In many software development projects, performance requirements are not addressed until after the application is developed or deployed, resulting in costly changes to the software or the acquisition of expensive high-...
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In many software development projects, performance requirements are not addressed until after the application is developed or deployed, resulting in costly changes to the software or the acquisition of expensive high-performance hardware. To remedy this, researchers have developed model-driven performance analysis techniques for assessing how well performance requirements are being satisfied early in the software lifecycle. In some cases, companies may not have the expertise to perform such analysis on their software; therefore they have an independent assessor perform the analysis. This paper describes an approach for conducting independent model-driven software performance assessments of UML 2.0 designs and illustrates this approach using a real-time signal generator as a case study
Many emerging applications operate on continuous unbounded data streams and need real-time data services. Providing deadline guarantees for queries over dynamic data streams is a challenging problem due to bursty stre...
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Many emerging applications operate on continuous unbounded data streams and need real-time data services. Providing deadline guarantees for queries over dynamic data streams is a challenging problem due to bursty stream rates and time-varying contents. This paper presents a prediction-based QoS management scheme for real-time data stream query processing in distributed environments. The prediction-based QoS management scheme features query workload estimators, which predict the query workload using execution time profiling and input data sampling. In this paper, we apply the prediction-based technique to select the proper propagation schemes for data streams and intermediate query results in distributed environments. The performance study demonstrates that the proposed solution tolerates dramatic workload fluctuations and saves significant amounts of CPU time and network bandwidth with little overhead
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