17173349
A lightweight process for change identification and regression test selection in using COTS components
Various regression test selection techniques have been developed and have shown fault detection effectiveness. The majority of these test selection techniques rely on access to source code for change identification. However, when new releases of COTS components are made available for integration and testing, source code is often not available. In this paper, we present a lightweight integrated-black-box approach for component change identification (I-BACCI) process for selection of regression tests for user/glue code that uses COTS components. I-BACCI is applicable when component licensing agreements do not preclude analysis of the binary files. A case study of the process was conducted on an ABB product that uses a medium-scale internal ABB software component. Five releases of the component were examined to evaluate the efficacy of the proposed process. The result of the case study indicates this process can reduce the required number of regression tests by 54% on average.
15164862
Experiences in initiating concurrency software research efforts
Multi-core CPUs are now common in modern computers. To get access to effectively an unlimited supply of compute resources, software programs that have been highly optimized to use a single CPU need to be converted where possible to use concurrency. We have initiated our concurrency software research for performance enhancement on a large-scale system with high throughput and low latency transactions. In this paper, we report our experience, experiments, and results in various aspects of concurrency design and programming, including multi-threaded prototypes, static and dynamic concurrency analysis, future techniques and trends, concurrency experiments, and concurrency design patterns. Based on the concurrency experiments, we achieved at least 80 percent overall performance increases as measured by transaction throughput. As a result, capital expenditures for large scale deployments can be significantly reduced.
39463231
Entropy Based Evaluation of Communication Predictability in Parallel Applications
The performance of parallel computing applications is highly dependent on the efficiency of the underlying communication operations. While often characterized as dynamic, these communication operations frequently exhibit spatial and temporal locality as well as regularity in structure. These characteristics can be exploited to improve communication performance if the correct prediction model is selected to a suitable communication topology. In this paper we describe an entropy based methodology for quantifying and evaluating the success of different prediction models on actual workloads drawn from representative parallel benchmarks. We evaluate two different prediction criteria and combinations thereof: (1) Messages are partitioned by source node. (2) Use of a first order context model. We also describe the threshold for predication designed to largely avoid incorrect predication overheads. Our results show for simple predication models, even on highly dynamic benchmark applications, predictability can be improved by several orders of magnitude. In fact, using simple prediction techniques, over 75% of the communication volume is accurately predictable.
224355
Architecture design of grid GIS and its applications on image processing based on LAN
Computer technology and its relative subjects developed at very high speed in recent years, so is geo-information science, including Geographic Information System (GIS), remote sensing (RS) and global position system (GPS). But with the increase of data, many data cannot be used efficiently because of the tremendous amount of data and information and the difficulty of process and transfer through network. So how to develop internet technology to solve these problems becomes a difficult problem for current computer experts and geo-science experts. Fortunately, grid computing provides us the method to solve this problem effectively. Grid computing is a resources sharing model presented by computer experts to solve current network resources imbalance problem. Basing on the application of grid computing on geographical information system (GIS), this paper analyzes the weakness and problems of traditional GIS, and then gives the method to solve these problems with the technology provided by grid computing and web services. After analyzing the characteristic of grid computing this paper expatiates on current application status of grid computing on GIS and the problems it faces, with the technology of middleware, this paper presents the architecture of grid GIS and lists the techniques it needs. In conclusion, this paper concludes that the distributing middleware architecture based on grid geographic markup language (GridGML) and web services technique is a good solution to current problems, this architecture can also solve those problems such as effective resources sharing through internet and advancing international application's efficiency, at last we discuss its implementation process based on LAN.
2684214
Switch design to enable predictive multiplexed switching in multiprocessor networks
Predictive multiplexed switching is a new approach for building interconnection switches for high performance parallel systems. This approach advocates sacrificing some link bandwidth in return for more efficient network control and simpler connection management. The main idea is to depart from the traditional packet and wormhole switching in favor of row data communication over established communication pipes (connections). The overhead of this circuit switching approach can be justified when established connections are repeatedly used before they are torn down. For this, we use multiplexing to allow multiple connections to share the same resources (links and switches), thus avoiding tearing down connections prematurely. The connection establishment overhead is further reduced by exploring communication locality and predictability in applications that exhibit these properties. We present the design of an interconnection system which is based on multiplexed switching and which establishes connections either reactively, in response to dynamically generated requests, or proactively, in response to compiler or application directives. A communication prediction component may be supported to reduce the network control overhead in applications that exhibit communication locality and predictability. The design is evaluated using hardware design, synthesis, and cycle-accurate simulation. Comparison with more traditional switching paradigms shows the potential of our predictive multiplexed switching approach.