this paper presents a distributed hardware/software cosimulation environment for heterogeneous systems prototyping applied to an industrial application. the environment provides following features: distributed Hw/Sw c...
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this paper presents a distributed hardware/software cosimulation environment for heterogeneous systems prototyping applied to an industrial application. the environment provides following features: distributed Hw/Sw cosimulation, automatic Hw/Sw interface generation, Hw elements can be described at different levels of abstraction and generic/specific Sw debuggers can be used. Starting from a brief description of the interface of the interconnected modules the tool automatically produces the link between Hw and Sw parts. In addition, the environment is very easy to use, even for complex systems that may include several Sw (C) modules and several Hw (VHDL) modules running in parallel. Applied to a large industrial multi-processor system, this method appeared reliable and efficient, providing important benefits in hardware-software codesign: better design environment and reduced time to validate.
Multipoint communication protocols that offer group membership and virtually synchronous message delivery are commonly believed to be heavyweight and non-scalable. To meet the needs of large-scale computer-supported c...
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ISBN:
(纸本)9781450373395
Multipoint communication protocols that offer group membership and virtually synchronous message delivery are commonly believed to be heavyweight and non-scalable. To meet the needs of large-scale computer-supported collaborative work, distributedparallel computing, and future worldwide applications, we designed the Structured Virtual Synchrony (SVS) protocol. the protocol has been implemented as part of Horus, a group communication system developed at Cornell University. It scales up to 800 members, while achieving a one-way latency of 100 milliseconds over groups of 500 members.
ITL and Tempura are used for respectively the formal specification and simulation of a large scale system, namely the general purpose multi threaded dataflow processor EP/3. the paper shows that this processor can be ...
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A number of schemes have been used in distributed database systems to coordinate the execution of the subtransactions of a global transaction. We study the performance of a simple modification to the basic two phase c...
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A number of schemes have been used in distributed database systems to coordinate the execution of the subtransactions of a global transaction. We study the performance of a simple modification to the basic two phase commit protocol called Prudent Two Phase Commit protocol. the protocol gives the transaction a second chance before it decides to abort it. this prudent approach prevents a transaction from aborting in case of transient communication failures and hence improves system performance and reliability. To measure the performance of this protocol, we simulate a distributed database system. the performance of this simulated distributed system is measured while using the Prudent, Basic, and Optimistic Two Phase Commit protocols. the results of this simulation study are presented with a discussion and interpretation of the graphs generated by the simulation. the results confirm the improvement in system performance withthe Prudent Two Phase Commit Protocol.
Object oriented database management systems are becoming popular and are being used in a large number of application domains, many of which are inherently distributed. Optimal application performance of a distributed ...
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Object oriented database management systems are becoming popular and are being used in a large number of application domains, many of which are inherently distributed. Optimal application performance of a distributed object oriented database system requires class fragmentation and the development of allocation schemes to place fragments at distributed sites in order to minimize data transfer. Our approach is top down, and the entity of fragmentation is the class. Fragmentation algorithms have been proposed for the relational model, but the object model is relatively untouched. We present an algorithm for vertical fragmentation in a model consisting of complex attributes and complex methods. this type of fragmentation facilitates query decomposition, optimization, and parallel treatment for distributed object oriented database systems.
We show an alternative way to optimize join sequences in a shared nothing architecture of the distributed relational DBMS HEAD. the hardware resources are also used for database independent applications in concurrency...
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We show an alternative way to optimize join sequences in a shared nothing architecture of the distributed relational DBMS HEAD. the hardware resources are also used for database independent applications in concurrency, for database access. To achieve a better hardware utilization we span a complete search space involving all intermediate shapes between left deep, right deep and bushy trees, but without join sequences including cartesian products. the approach is based on any combinatorial search engine and a complex cost function. the cost function involves the actual load of the processors, the network load, and the memory capacities. the new technique has free access to any join sequence in the whole search space. the approach is not restricted to acyclic join conditions.
A common paradigm for distributed computing is the producer-consumer model. One set of processes produce objects (data, resources, or tasks) that are consumed by another set of processes. We present a simple algorithm...
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A common paradigm for distributed computing is the producer-consumer model. One set of processes produce objects (data, resources, or tasks) that are consumed by another set of processes. We present a simple algorithm for implementing a distributed queue. this algorithm has several parameters that need to be tuned, such as the number of probes to find an object, the amount of buffering, and the connectivity between the producers and the consumers. We provide an analytical model that predicts performance, and based on the analytical model we provide recommendations for setting the parameters. Our analytical model is validated by a comparison to simulation results.
In this paper we present a simulation methodology for evaluating and understanding parallel computer architectures. the simulation tool that we have developed can generalize the effect of architectural features while ...
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In this paper we present a simulation methodology for evaluating and understanding parallel computer architectures. the simulation tool that we have developed can generalize the effect of architectural features while maintaining the complex interactions of architecture and algorithm typical of a real computer system. We will show that our simulator is an accurate tool for predicting the performance of real world computers. Our approach is unique in that not only can the costs of various architectural features be modified, but aspects of the program running on the simulated architecture can be modified by the simulator as well. Issues such as task granularity, communication requirements, global versus local memory usage, floating point usage, etc. can be generalized.
the proceedings contain 48 papers. the topics discussed include: a layered architecture for real-time applications;hyperreal one: the implementation, the environment, and an example;dynamic replacement of software in ...
ISBN:
(纸本)0818671122
the proceedings contain 48 papers. the topics discussed include: a layered architecture for real-time applications;hyperreal one: the implementation, the environment, and an example;dynamic replacement of software in hard real-time systems: practical assessment;measuring the real-time operating system performance;visualization of real-time software in host-based simulation environment;a scheduling problem language;a dedicated digital unit for event recognition and centroiding in photon counting intensified CCDs;pessimistic deadline ceiling protocol: a concurrency control protocol under earliest deadline first scheduling;issues in schedulability analysis of real-time systems;scheduling algorithms for improving the response in intelligent environments;increasing schedulability in distributed hard real-time systems;and hybrid specification and formal distributed heterogeneous prototyping of distributed real-time systems.
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