Even the more or less "canonical", lower-level architecture of information systems needs to be revisited from time to time. Notions like persistence and transactions belong traditionally to the area of datab...
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Even the more or less "canonical", lower-level architecture of information systems needs to be revisited from time to time. Notions like persistence and transactions belong traditionally to the area of database management systems. There are, however many applications, such as CAD, VLSI design or simulation, which need persistence and could take advantage of transactions, but require especially fast implementations not provided by DBMS. We describe a low-level transaction concept used to implement our parallel main memory object store (PPOST), to provide main memory access times combined with the safety and convenience of transactions.
Data staging is an important data management problem for a distributed heterogeneous networking environment, where each data storage location and intermediate node may have specific data available, storage limitations...
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Data staging is an important data management problem for a distributed heterogeneous networking environment, where each data storage location and intermediate node may have specific data available, storage limitations, and communication links. Sites in the network request data items and each item is associated with a specific deadline and priority. It is assumed that not all requests can be satisfied by their deadline. The work concentrates on solving a basic version of the data staging problem in which all parameter values for the communication system and the data request information represent the best known information collected so far and stay fixed throughout the scheduling process. A mathematical model for the basic data staging problem is introduced. Then, a multiple-source shortest-path algorithm based heuristic for finding a suboptimal schedule of the communication steps for data staging is presented. A simulation study is provided, which evaluates the performance of the proposed heuristic. The results show the advantages of the proposed heuristic over two random based scheduling techniques. This research, based on the simplified static model, serves as a necessary step toward solving the more realistic and complicated version of the data staging problem involving dynamic scheduling, fault tolerance, and determining where to stage data.
The proceedings contains 26 papers from the 11th workshop on parallel and distributedsimulation (PADS'97). Topics discussed include: conservative simulation;architecture and VLSI simulation;event simultaneity;VLS...
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The proceedings contains 26 papers from the 11th workshop on parallel and distributedsimulation (PADS'97). Topics discussed include: conservative simulation;architecture and VLSI simulation;event simultaneity;VLSI circuit partitioning;optimistic simulation;Petri net simulation;interconnection computer network;distributedsimulation;Hierarchical Tool HIT;Multi-Resolution Entity;bulk synchronous parallel models;and parallelsimulation environments.
This paper shows how the Prosit system, a new C + +-based framework for both sequential and distributed discrete event simulation, developed at INRIA-Sophia-Antipolis, makes an easy and efficient integration of classi...
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This paper shows how the Prosit system, a new C + +-based framework for both sequential and distributed discrete event simulation, developed at INRIA-Sophia-Antipolis, makes an easy and efficient integration of classical discrete event simulation and of new high speed simulation techniques based on evolution equations possible. This demonstrates in particular the feasibility of distributedsimulations involving simulators of different nature. Important applications of these techniques may be found in the simulation of communication switches, as illustrated in an example.
With two examples we show the suitability of the bulk-synchronous parallel (BSP) model for discrete-event simulation of homogeneous large-scale systems. This model provides a unifying approach for general purpose para...
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ISBN:
(纸本)0818679654
With two examples we show the suitability of the bulk-synchronous parallel (BSP) model for discrete-event simulation of homogeneous large-scale systems. This model provides a unifying approach for general purpose parallel computing which in addition to efficient and scalable computation, ensures portability across different parallel architectures. A valuable feature of this approach is a simple cost model that enables precise performance prediction of BSP algorithms. We show both theoretically and empirically that systems with uniform event occurrence among their components, such as colliding hard-spheres and ising-spin models, can be efficiently simulated in practice on current parallel computers supporting the BSP model.
This paper presents the tolerant, hybrid synchronization schema and its benefits for the parallel and distributedsimulation of interconnected computer networks. The hybrid schema combines conservative and optimistic ...
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ISBN:
(纸本)0818679654
This paper presents the tolerant, hybrid synchronization schema and its benefits for the parallel and distributedsimulation of interconnected computer networks. The hybrid schema combines conservative and optimistic synchronization approaches by using lookahead for scheduling special events and using the flexibility of Time Warp in certain cases. In addition to these classical approaches the introduction of the ''tolerance'' allows the distributed modules to simulate further ahead than guaranteed by the conservative synchronization schema. This results in significantly smaller simulation runtimes and many other benefits.
Performance analysis of distributed systems may be performed on different levels of abstraction. An accurate but time-consuming method is the construction of a simulation model which includes the different subsystems,...
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ISBN:
(纸本)0818680970
Performance analysis of distributed systems may be performed on different levels of abstraction. An accurate but time-consuming method is the construction of a simulation model which includes the different subsystems, the communication system, and the load profile. In particular, this approach seems to be very powerful for real-time systems because of the inherent possibility of precise calculations of delays and processing times. A VHDL-based approach is presented which supports the performance analysis of mixed discrete-continuous, distributed systems.
In this paper we address the problem of efficiently performing parallel discrete-event simulation in the case that events elaboration is dependent of other processes' local states. We propose a parallelsimulation...
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ISBN:
(纸本)0818679654
In this paper we address the problem of efficiently performing parallel discrete-event simulation in the case that events elaboration is dependent of other processes' local states. We propose a parallelsimulation policy, called State Query Time Warp (SQTW), based on the Time Warp mechanism. We present experiments performed by means of a SQTW-based parallel simulator on a T-800 transputer machine for solving performance models based on state-dependent routing queueing network models. The experiments are used for assessing overheads and efficiency involved by SQTW;results show that high efficiency is achievable, and surprisingly reveal SQTW is able to globally reduce rollback overheads with respect to corresponding Time Warp simulations.
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