this paper examines the CORBA Naming, Event, Notification, Trading, Time and Security Services, withthe objective of identifying the issues that must be addressed in order make these Services fault-tolerant. the reli...
详细信息
ISBN:
(纸本)0769515584
this paper examines the CORBA Naming, Event, Notification, Trading, Time and Security Services, withthe objective of identifying the issues that must be addressed in order make these Services fault-tolerant. the reliability considerations for each of these Services involves strategies for replicating the Service objects, and for keeping the states of the replicas consistent. Of particular interest are the sources of non-determinism in each of these Services, along withthe means for addressing the non-deterministic behavior in the interests of ensuring strong fault tolerance.
Application programs are performed on clients and issue requests to object servers. the object servers then send responses to the clients. On the other hand, programs named agents move to object servers where the agen...
详细信息
Weapons System Open Architecture (WSOA) utilizes a distributed object computing foundation as a "bridge" to enable communication between disparate real-time systems in the redirection of strike assets. this ...
详细信息
ISBN:
(纸本)0769515584
Weapons System Open Architecture (WSOA) utilizes a distributed object computing foundation as a "bridge" to enable communication between disparate real-time systems in the redirection of strike assets. this open systems "bridge" connects legacy embedded mission systems and off-board C3I (Command, Control, Communication and Information) sources and systems. WSOA will establish the potential gains in warfighting capability due to the enabling technologies of collaborative planning, information mining, and adaptive embedded resource management. this paper focuses on the experiences and lessons learned in the WSOA demonstration program with CORBA middleware, pluggable protocols and Quality of Service (QoS) enforcement, management and verification.
this paper discusses the software architecture of a Real-time CORBA object request broker (ORB) called ZEN, written in Real-time Java, which is designed to eliminate common sources of overhead and non-determinism in O...
详细信息
ISBN:
(纸本)0769515584
this paper discusses the software architecture of a Real-time CORBA object request broker (ORB) called ZEN, written in Real-time Java, which is designed to eliminate common sources of overhead and non-determinism in ORB implementations. We illustrate how ZEN can be configured to select the minimal set of components used by an application. Our experience with ZEN indicates that combining Real-time Java with Real-time CORBA is a major step forward towards simplifying the development and maintenance of distributed middleware and applications with stringent quality of service requirements.
the Real-Time Specification for Java (RTSJ) provides many mechanisms for "real-world" programming, including the ability to express timeliness constraints for computations, respond to asynchronous events, an...
详细信息
ISBN:
(纸本)0769515584
the Real-Time Specification for Java (RTSJ) provides many mechanisms for "real-world" programming, including the ability to express timeliness constraints for computations, respond to asynchronous events, and access physical memory, As a demonstration of the real-world capabilities of the RTSJ, we implemented an autonomous mobile robot programmed solely in Java. In this paper, we describe the implementation of this robotic control software, as well as other examples of device-level software in the Java programming language.
this paper describes a replication algorithm for distributed real-time object-oriented databases in a static environment. All data requirements are specified a priori, and the algorithm creates replication transaction...
详细信息
ISBN:
(纸本)0769515584
this paper describes a replication algorithm for distributed real-time object-oriented databases in a static environment. All data requirements are specified a priori, and the algorithm creates replication transactions that copy remote data to a local site in order to guarantee that every data request reads temporally valid data. the algorithm conditions are proven to be necessary and sufficient for providing this guarantee. Test results indicate that under most conditions, this replication strategy is better than total replication, which is a typical strategy used in distributed databases.
We present in this paper an unreliable distributed timing scrutinizer (UDTS), this mechanism captures the state of the network and, based on its observation, estimates the waiting time that maximizes the efficiency of...
详细信息
ISBN:
(纸本)0769515584
We present in this paper an unreliable distributed timing scrutinizer (UDTS), this mechanism captures the state of the network and, based on its observation, estimates the waiting time that maximizes the efficiency of a round-based protocol regarding the number and/or the duration of its computational rounds. An UDTS is not an abstract oracle, it is implementable and reveals the properties of the network. We illustrate our approach by addressing the consensus problem in asynchronous distributed systems equipped with an unreliable distributed timing scrutinizer the proposed protocol is conceptually simple. It benefits from the UDTS predictions to implement different convergence and decision conditions. this allows the protocol to be efficient in number and/or duration of rounds for stable networks.
Maximizing parallelism and minimizing communication overheads are important issues on distributed-memory systems. this paper presents a communication optimization technique named redundant computation partitioning, an...
详细信息
Component-based infrastructures provide support for the development and execution of component-based si,stems. However they have limitations in their application in real-time and reliable systems, because they do not ...
详细信息
ISBN:
(纸本)0769515584
Component-based infrastructures provide support for the development and execution of component-based si,stems. However they have limitations in their application in real-time and reliable systems, because they do not integrate facilities to support these types of problems and include limitations of predictability and dependability. these infrastructures are designed to provide support to financial and e-commerce applications;they integrate as basic services the transaction, persistence, security and events. these are useful services in real-time and telecom applications, but these applications require other types of services to provide predictability and reliability. Me introduce some practical solutions to integrate OoS (Quality of Service) services in the component infrastructures and the results that their business components can expect.
Group communication in real-time computing systems is useful for building fault-tolerant distributed real-time applications. the purpose of this paper is to show the efficiency of the group membership manager executin...
详细信息
ISBN:
(纸本)0769515584
Group communication in real-time computing systems is useful for building fault-tolerant distributed real-time applications. the purpose of this paper is to show the efficiency of the group membership manager executing the multicast protocol RRFM(Release-time based Fault-tolerant Real-time Multicast) which is based on the idea of attaching the official release time to each group view send message. In this approach, the group membership manager interacts withthe fault detector and the client application do not send view-ack message to the group membership manager. A real-time simulation based on the TMO structuring scheme is conducted to study its performance for boththe proposed approach and the group management scheme which receives view-ack messages. Simulation results show that with a proper value of the official release time interval, our approach improves the delay in completing the group view change event.
暂无评论