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international symposium on Database Engineering and Applications (IDEAS)

作者： C. Nippl R. Rantzau B. Mitschang Department of Computer Science Technical University Munich Munich Germany Institute of Parallel and Distributed High Performance Systems University of Stuttgart Stuttgart Germany

Today many applications routinely generate large quantities of data. The data often takes the form of (time) series, or more generally streams, i.e. an ordered sequence of records. Analysis of this data requires stream processing techniques which differ in significant ways from what current database analysis and query techniques have been optimized for. In this paper we present a new operator, called StreamJoin, that can efficiently be used to solve stream-related problems of various applications, such as universal quantification, pattern recognition and data mining. Contrary to other approaches. StreamJoin processing provides rapid response times, a non-blocking execution as well as economical resource utilization. Adaptability to different application scenarios is realized by means of parameters. In addition, the StreamJoin operator can be efficiently embedded into the database engine, thus implicitly using the optimization and parallelization capabilities for the benefit of the application. The paper focuses on the applicability of StreamJoin to integrate application semantics into the DBMS.

关键词： databases Data analysis Proteins Itemsets Application software Data mining Sequences Decision support systems Computer science Pattern recognition

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Self-stabilizing mutual exclusion using unfair distributed scheduler

Proceedings of the International Parallel Processing Symposi...

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proceedings of the international parallel Processing symposium, IPPS 2000年 465-470页

作者： Datta, Ajoy K. Gradinariu, Maria Tixeuil, Sebastien Univ of Nevada Las Vegas Las Vegas United States

A self-stabilizing algorithm, regardless of the initial system state, converges infinite time to a set of states that satisfy a legitimacy predicate without the need for explicit exception handler of backward recovery. Mutual exclusion is fundamental in the area of distributed computing, by serializing the accesses to a common shared resource. All existing probabilistic self-stabilizing mutual exclusion algorithms designed to work under an unfair distributed scheduler suffer from the following common drawback: Once stabilized, there exists no upper bound of time between two executions of the critical section at a given node. We present the first probabilistic self-stabilizing algorithm that guarantees such a bound (O(n3), where n is the network size) while working using an unfair distributed scheduler. As the scheduling adversary gets weaker, the bound gets better. Our algorithm works in an anonymous unidirectional ring of any size and has a O(n3) expected stabilization time. Due to space restriction, proofs are omitted from this extended abstract and can be found in [5].

关键词： distributed computer systems

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Enhancing NWS for use in an SNMP managed Internetwork

Proceedings of the International Parallel Processing Symposi...

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proceedings of the international parallel Processing symposium, IPPS 2000年 506-511页

作者： Busby Jr., Robert E. Neilsen, Mitchell L. Andresen, Daniel AT&T Network Operations Bridgeton United States

The Network Weather Service (NWS) is a distributed resource monitoring and utilization prediction system, employed as an aid to scheduling jobs in a metacomputing environment. We have enhanced the Network Weather Service by providing a broader metric set, forecast trend visualization, and asynchronous notification. Three new components have been added to the NWS system. The first of these is an SNMP Sensor that may be used to collect data being tracked by SNMP agents. Secondly, a Notification Process provides asynchronous events to interested applications when metrics tracked by NWS are expected to exceed established normal ranges. Finally, an extended SNMP agent daemon has been developed to provide SNMP-enabled applications with the ability to retrieve information from NWS without the need for custom programming. The new modules help to position NWS as an integral component for performing QoS monitoring and fault prediction in an SNMP-based fault management architecture. We also demonstrate that the additional functionality adds a minimal amount of overhead to the system, and reported bandwidth utilization correlates closely with results from the invasive NWS bandwidth sensor.

关键词： parallel processing systems

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Coherence communication prediction in shared-memory multiprocessors

Coherence communication prediction in shared-memory multipro...

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IEEE symposium on High-Performance Computer Architecture

作者： S. Kaxiras C. Young Bell Laboratories Lucent Technologies Inc. USA

Sharing patterns in shared-memory multiprocessors are the key to performance: uniprocessor latency-tolerating techniques such as out-of-order execution and non-blocking caches have proved unable to completely hide the latency of remote memory access. Recently proposed prediction mechanisms accelerate coherence protocols by guessing where data will be used next and forwarding them to potential users before they are requested. Prior work in such shared-memory prediction schemes resulted in address-based and instruction-based predictors. Our work innovates in three areas. first, we present a taxonomy of prediction schemes that includes all previously-proposed prediction schemes in a uniform space. Second, we show how statistical techniques from epidemiological screening and polygraph testing can be applied to better measure the effectiveness of sharing prediction schemes; earlier work had reported only the ratio of incorrect predictions to correct predictions but neglected the ratio of correct predictions to actual sharing. Third, we provide simulation results of the accuracy of a practical subset of the space of schemes in our taxonomy, then analyze which components of each scheme contribute the most to prediction accuracy. Through this process, we discovered prediction schemes more accurate than those previously proposed.

关键词： Delay Access protocols Taxonomy Logic testing Performance gain parallel machines distributed computing Time sharing computer systems Impedance

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Design and performance evaluation of parallel algorithms for path expressions in object database systems on now

Design and performance evaluation of parallel algorithms for...

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1999 international symposium on Database Applications in Non-Traditional Environments, DANTE 1999

作者： Fang, Qiang Wang, Giiorcn Yu, Go Kanoko, Kimihiko Makinouchi, Akifumi School of Information Science and Engineering Northeastern University Shenyang110006 China Graduate School of Information Science and Electrical Engineering Kyushu University Fuknoka812 Japan

ISBN: (纸本)0769504965

In OODB, path expressions are usually used for navigating through complex objects and obtaining necessary information at the far end of a sequence of object *** parallel forward pointer chasing algorithm (PFPC) and parallel backward pointer algorithm (PBPC) are natural algorithms for path *** we change the implicit joins in the path expression into explicit joins, parallel join algorithms can also be employed for path *** order to improve performance in a distributed environment, semi-join operations replace the join operations, which is called the parallel cascade semi-join algorithm (PCSJ).This paper mainly describes and compares PFPC and PCSJ algorithms implemented on DSVM;then analyzes the performance of algorithms from test results according to a certain *** can see PCSJ has much better performance than PFPC by the *** parallel algorithms exploit pipelining and I/O communication parallelism;making full use of DSVM *** valuable ideas are obtained from the theory analysis and practical testing © 2000 IEEE.

关键词： Object-oriented databases

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Implementation of a virtual time synchronizer for distributed databases

Proceedings of the International Parallel Processing Symposi...

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proceedings of the international parallel Processing symposium, IPPS 1999年 733-737页

作者： Boukerche, Azzedine Das, Sajal K. Datta, Ajoy LeMaster, Timothy E. Univ of North Texas Denton United States

The availability of high speed networks and improved microprocessor performance have made it possible to build inexpensive cluster of workstations as an appealing platform for parallel and distributed computing. In this paper, we study the performance of a distributed database system synchronized by virtual time (VT) mechanism by experimenting on a LAN-connected collection of 12 Sun-SPARCS workstations. Our experimental results demonstrate that the VT synchronization protocol is a viable concurrency control method, and it yields about 25-30% reduction in the response time, when compared with a widely used, multiversion (MV) concurrency control scheme based on timestamps order. The reason for comparing with the MV approach is that both virtual time and multiversion protocols are based upon the concept of timestamps, and attain high performance by using multiple version of the data objects.

关键词： distributed database systems

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Object-oriented design of adaptive multicast communications

Object-oriented design of adaptive multicast communications

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international symposium on parallel Architectures, Algorithms and Networks (ISPAN)

作者： Weiming Zhang Weijia Jia Department of Computer Science City University Hong Kong China

Multicast (group) communications have been widely recognized by current research and industry. Multicast is very useful for various network applications such as distributed (replicated) database, video/audio conference, information distribution and server locations etc. But design and implementation of such multicast communication systems in networks are complicated tasks, especially when quality of service (QoS) of applications such as real time and reliability are desired. In order to quickly design and implement multicast communication, good tools are crucial and must be facilitated. The paper presents a novel object oriented (OO) QoS driven approach for the quick design and prototyping of multicast communication systems under certain QoS requirements, for multicast message transmission and receptions such as real time, total ordering, atomicity and fault tolerance etc.

关键词： Multicast communication Quality of service Real time systems Communication industry distributed databases Object oriented databases Audio databases Videoconference Network servers Telecommunication network reliability

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Evaluation of active disks for decision support databases

Evaluation of active disks for decision support databases

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The 6th international symposium on High-Performance Computer Architecture (HPCA-6)

作者： Uysal, Mustafa Acharya, Anurag Saltz, Joel HP Labs Palo Alto United States

Growth and usage trends for large decision support databases indicate that there is a need for architectures that scale the processing power as the dataset grows. To meet this need, several researchers have recently proposed Active Disk architectures which integrate substantial processing power and memory into disk units. In this paper, we evaluate Active Disks for decision support databases. first, we compare the performance of Active Disks with that of existing scalable server architectures: SMP-based conventional disk farms and commodity clusters of PCs. Second, we evaluate the impact of several design choices on the performance of Active Disks. We focus on the performance impact of interconnect bandwidth, amount of disk memory and disk-to-disk communication architecture on decision support workloads. Our results show that for identical disks, number of processors and I/O interconnect, Active Disks provide better price/performance than both SMP-based conventional disk farms and commodity clusters. Experiments evaluating the impact of design alternatives in Active Disk architectures indicate that: (1) for configurations up to 64 disks, a dual fibre channel arbitrated loop interconnect is sufficient even for the most communication-intensive decision support tasks;(2) most decision support tasks do not require a large amount of memory;and (3) direct disk-to-disk communication is necessary for achieving good performance on tasks that repartition all (or a large fraction of) their dataset.

关键词： parallel processing systems

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Implementation of a virtual time synchronizer for distributed databases

Implementation of a virtual time synchronizer for distribute...

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international symposium on parallel Processing

作者： A. Boukerche S.K. Das A. Datta T.E. LeMaster Department of Computer Science University of North Texas Denton TX USA Department of Computer Science University of Nevada Las Vegas NV USA

关键词： distributed databases Database systems Protocols Workstations Concurrency control Computer science distributed computing Object oriented modeling Concurrent computing System recovery

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parallel algorithms for 3D reconstruction of asymmetric objects from electron micrographs

Parallel algorithms for 3D reconstruction of asymmetric obje...

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international symposium on parallel Processing

作者： R.E. Lynch D.C. Marinescu H. Lin T.S. Baker Department of Computer Sciences Purdue University USA

We present new parallel algorithms for 3D reconstruction of objects from 2D projections and their application for the determination of the structure of macromolecules from electron micrographs. A multi-resolution orientation determination algorithm uses a parallel search to determine the 'best fit' of a given image with images in a reference database. The 3D reconstruction algorithm uses Cartesian coordinates and permits the reconstruction of objects that do not possess symmetries. The method decomposes a large linear system into a set of smaller systems that can be solved independently on different processors of a parallel computer or on a cluster of workstations. The paper outlines the reconstruction process and the data partitioning and load balancing issues pertinent to the parallel implementation of the algorithm; preliminary results obtained on a SGI Origin 2000 system are given.

关键词： parallel algorithms Image reconstruction Electrons Position measurement Image databases Object oriented databases Reconstruction algorithms Linear systems Concurrent computing Workstations

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