Cooperative Information systems (CIS) often consist of applications that access shared resources such as databases. Since centralized systems may have a great impact on the system performance, parallel and distributio...
详细信息
ISBN:
(纸本)0818683805
Cooperative Information systems (CIS) often consist of applications that access shared resources such as databases. Since centralized systems may have a great impact on the system performance, parallel and distribution techniques are needed for attaining scalability. distributeddatabases are, then, crucial for the development of cooperative applications. However, in order to improve performance, it is very important to design information distribution properly, which is the goal of Distribution Design. Considering the various difficulties embedded in the Design of distributed Object Oriented databases, this work presents an algorithm to assist distribution designers in their task. The analysis algorithm indicates the most adequate fragmentation technique (vertical, horizontal or mixed) for each class in the database schema, and we propose the use of a machine learning method - inductive Logic Programming - to uncover some implicit issues to be considered in the distribution design, thus revising the proposed analysis algorithm.
The use of parallel database systems to deliver high performance has become quite common. Although queries submitted to these database systems are executed in parallel, the interaction between applications and current...
详细信息
ISBN:
(纸本)0818678089
The use of parallel database systems to deliver high performance has become quite common. Although queries submitted to these database systems are executed in parallel, the interaction between applications and current pal allel database systems is serial. As the complexity of the applications and the amount of data they access increases, the need to parallelize applications also increases. In this parallel application environment, a serial interface to the database could become the bottleneck in the performance of the application. Hence, parallel database systems should support interfaces that allow the applications to interact with the database system in parallel. In this paper we present a taxonomy of such parallel interfaces, namely, the Single Coordinator, Multiple Coordinator, Hybrid parallel, and Pure parallel interfaces. Furthermore, we discuss how each of these interfaces can be realized and in the process introduce new constructs that enable the implementation of the interfaces. We also qualitatively evaluate each of the interfaces with respect to their restrictiveness and performance impact.
The Loop-Level Process Control (LLPC) policy [9] dynamically adjusts the number of threads an application is allowed to execute based on the application's available parallelism and the overall system load. This st...
详细信息
ISBN:
(纸本)0818684038
The Loop-Level Process Control (LLPC) policy [9] dynamically adjusts the number of threads an application is allowed to execute based on the application's available parallelism and the overall system load. This study demonstrates the feasibility of incorporating the LLPC strategy into an existing commercial operating system and parallelizing compiler and provides further evidence of the performance improvement that is possible using this dynamic allocation strategy. In this implementation, applications are automatically parallelized and enhanced with the appropriate LLPC hooks so that each application interacts with the modified version of the Solaris operating system. The parallelism of the applications is then dynamically adjusted a automatically when they are executed in a multiprogrammed environment so that all applications obtain a fair share of the total processing resources.
Split execution is a common model for providing a friendly environment on a foreign machine. In this model, a remotely executing process sends some or all of its system calls back to a home environment for execution. ...
详细信息
ISBN:
(纸本)0769507832;0769507840
Split execution is a common model for providing a friendly environment on a foreign machine. In this model, a remotely executing process sends some or all of its system calls back to a home environment for execution. Unfortunately, hand-coding split execution system for experimentation and research is difficult and error-prone. We have built a tool, Bypass, for quickly producing portable and correct split execution systems for unmodified legacy applications. We demonstrate Bypass by using it to transparently connect a POSIX application to a simple data staging system based on the Globus toolkit.
In this paper a new method is proposed to synchronize massively parallel processes in distributed multiprocessor systems. The method is an extension of that used in arbitration systems like Futurebus+. It also uses th...
详细信息
ISBN:
(纸本)0818682596
In this paper a new method is proposed to synchronize massively parallel processes in distributed multiprocessor systems. The method is an extension of that used in arbitration systems like Futurebus+. It also uses three global synchronization lines and a distributed synchronizer, and can be applied without changes to the existing hardware. The method allows to carry out two alternative synchronization protocols where the end of the operation is either forced by any processor or identified as a moment when all processors completed their individual parts. Application of this method, e.g., to the arbitration process allows to reduce the arbitration time in average by a factor of 2.
A parallel implementation of the 2D discrete wavelet transform on a distributed memory multiprocessor system called PARNEU is presented. The mapping has been chosen with consideration to load balancing and communicati...
详细信息
A parallel implementation of the 2D discrete wavelet transform on a distributed memory multiprocessor system called PARNEU is presented. The mapping has been chosen with consideration to load balancing and communication methods in order to achieve the best possible scalability and performance in transforming one single image. Detailed performance figures are included. Experimental results show that significant parallel speedup is reached with this mapping.
Low-level language constructs used for expressing explicit communication, concurrency, synchronization, and parallelism in systems make the systems difficult to maintain. For example, many programming languages allow ...
详细信息
ISBN:
(纸本)0769520944
Low-level language constructs used for expressing explicit communication, concurrency, synchronization, and parallelism in systems make the systems difficult to maintain. For example, many programming languages allow programmers to create parallel processes by using the fork/join statement and provide locking mechanisms to synchronize the resulting parallel computation. However, since fork/join may appear anywhere in a program, program making unstructured use of the language constructs may be difficult to understand and debug. We are presenting a middleware-based approach to distributed coordinated parallel programming. A familiar programming model will be provided to support implicit communication, concurrency, synchronization, and parallelism in systems through an implicit coordination-oriented approach. In other words, programmers do not have to explicitly express communication, concurrency, synchronization, and parallelism when they are developing distributedsystems for parallel processing. In addition, a 4-layered interconnection architecture will be implemented to support the programming model in an integrated manner. The implicit coordination-oriented approach to supporting parallel programming provides a number of benefits. Without inserting the low-level language constructs in an unstructured manner in programs makes the programs modular. Modularity improves the maintainability of the programs. Our approach supports the portability of programs by allowing the programs in different programming languages to be executed in any general programming environment without modifications.
暂无评论