5670471
Design, implementation and performance evaluation of GridRPC programming middleware for a large-scale computational grid
This paper reports on the design, implementation and performance evaluation of a suite of GridRPC programming middleware called Ninf-G Version 2 (Ninf-G2). Ninf-G2 is a reference implementation of the GridRPC API, a proposed GGF standard. Ninf-G2 has been designed so that it provides 1) high performance in a large-scale computational Grid, 2) the rich functionalities which are required to adapt to compensate for the heterogeneity and unreliability of a Grid environment, and 3) an API which supports easy development and execution of Grid applications. Ninf-G2 is implemented to work with basic Grid services, such as GSI, GRAM, and MDS in the Globus Toolkit version 2. The performance ofNinf-G2 was evaluated using a weather forecasting system which was developed using Ninf-G2. The experimental results indicate that high performance can be attained even in relatively fine-grained task-parallel applications on hundreds of processors in a Grid environment.
16039028
Overlay Weaver: An overlay construction toolkit
A layered model of structured overlays has been proposed and it enabled development of a routing layer independently of higher-level services such as DHT and multicast. The routing layer has to include other part than a routing algorithm, which is essential for routing. It is routing process, which is common to various routing algorithms and can be decoupled from a routing algorithm. We demonstrated the decomposition by implementing an overlay construction toolkit Overlay Weaver. It facilitates implementation of routing algorithms and we could multiple well-known algorithms just in hundreds of lines of code with the toolkit. The decomposition also enables multiple implementations of the common routing process. Two implementations the toolkit provides perform iterative and recursive routing, respectively. Additionally, to our knowledge, the toolkit is the first feasibility proof of the layered model by supporting multiple algorithms and the higher-level services. Such modular design contributes to our goal, which is facilitation of rapid development of realistic routing algorithms and their application. We demonstrates that Overlay Weaver supports the goal by conducting large-scale tests and comparisons of algorithms on a single computer. The resulting algorithm implementations work on a real TCP/IP network as it is.
16646144
Lessons learned through driving science applications in the PRAGMA grid
This paper describes the coordination, design and implementation of the PRAGMA Grid. Applications in genomics, quantum mechanics, climate simulation, organic chemistry and molecular simulation have driven the middleware requirements, and the PRAGMA Grid provides a mechanism for science and technology teams to collaborate, for grids to interoperate and for international users to share software beyond the essential, de facto standard Globus core. Several middleware tools developed by researchers within PRAGMA have been deployed in the PRAGMA grid and this has enabled significant insights, improvements and new collaborations to flourish. In this paper, we describe how human factors, resource availability and performance issues have affected the middleware, applications and the grid design. We also describe how middleware components in grid monitoring, grid accounting and grid file systems have dealt with some of the major characteristics of our grid. We also briefly describe a number of mechanisms that we have employed to make software easily available to PRAGMA and global grid communities.
13995472
Grid PSE builder: a framework for building Web-based distributed PSE on grid
In order to provide a framework for building Web-based distributed PSEs (problem solving environment) on a grid, we have been designing and implementing grid PSE builder. By using grid PSE builder, PSE providers can easily build a PSE using existing large scale scientific-engineering application as PSE components, without specialized knowledge about Web security and programming. On the other hand, PSE user can access the PSE with highly secured way only by using a Web interface. We have built some Web application portals with existing applications by using grid PSE builder as a Web portal toolkit and it is possible to make existing applications into PSE components with only a small amount of work.
217877
Relis-G: remote library install system for computational grids
When a grid user installs the library which is used by the GridRPC etc. to the servers distributed over a grid, the user needs to solve complicated and laborious problems, such as user's effort to input commands for remote operation, creation of an installation package of the library for heterogeneous server systems, avoidance of redundant compilation, and observance of administration policy of each server. In order to enable the user to solve these problems easily, we propose the remote library install system, Relis-G, which is highly portable and multipurpose in the grid. Besides the function for automatic remote library installation, this system offers functions, such as automatic creation of an installation package, automatic avoidance of redundant compilation, and automatic observance of administration policy of each server. Moreover, we confirmed that this system mitigated the above-mentioned user's burden greatly by operation tests.
6558101
The design and implementation of a fault-tolerant RPC system: Ninf-C
We describe the design and implementation of a fault tolerant GridRPC system, Ninf-C, designed for easy programming of large-scale master-worker programs that take from few days to few months for its execution in a grid environment. Ninf-C employs Condor, developed at University of Wisconsin, as the underlying middleware supporting remote file transmission and checkpointing for system-wide robustness for application users on the grid. Ninf-C layers all the GridRPC communication and task parallel programming features on top of Condor in a non-trivial fashion, assuming that the entire program is structured in a master-worker style-in fact, older Ninf master-worker programs can be run directly or trivially ported to Ninf-C. In contrast to the original Ninf, Ninf-C exploits and extends Condor features extensively for robustness and transparency, such as 1) checkpointing and stateful recovery of the master process, 2) the master and workers mutually communicating using (remote) files, not IP sockets, and 3) automated throttling of parallel GridRPC calls; and in contrast to using Condor directly, programmers can set up complex dynamic workflow as well as master-worker parallel structure with almost no learning curve involved. To prove the robustness of the system, we performed an experiment on a heterogeneous cluster that consists of x86 and SPARC CPUs, and ran a simple but long-running master-worker program with staged rebooting of multiple nodes to simulate some serious fault situations. The program execution finished normally avoiding all the fault scenarios, demonstrating the robustness of Ninf-C.
27048178
Mechanism and control of mobile pipeline maintenance robot with lazy tongs mechanism
A new type of mobile pipeline maintenance robot has been designed to clarify the feasibility of lazy tongs mechanism for adaptation to various size pipelines. The robot basically consists of three modules with two joints between modules and can move straight and spirally along the surface of pipeline. The robot can change its arm length in order to move on the pipeline of various size from 25 A to 100 A, and pass over obstacles such as reducer, diffuser, flange and other plant equipment. The control of the robot is so complicated that the modified dual control mode is introduced using the coordinate transformation matrix. By calculating the position and attitude of the robot under the control mode, the manoeuvrability of passing over a reducer is shown with experimental results.
42879781
Vision based navigation system by variable template matching for autonomous mobile robot
We have previously developed a navigation system for autonomous mobile robots. It can find landmarks on the ceiling to move and work. However, it is impossible to recognize landmarks when the size of landmark is different from the size of template. In such cases, the robot cannot continue to work. Therefore we proposed variable template matching (VTM) that makes it possible to recognize landmarks of different sizes. We realize VTM by using the optimization method called the evolution strategy (ES). The robot can recognize the landmark faster, inferring landmark parameters by binary density projection.