Hierarchical control policy for dynamic resource management in grid virtual organization

This paper proposes a hierarchical control system in grid virtual organization. The hierarchical system can be decomposed into multiple application groups, which can be further decomposed into multiple applications. At the top of the hierarchy, the global controller controls the gross allocation of resources to the groups. At the next level down, the group controller coordinates the local deployments of all applications that consume the local allocation of resources. At the lowest level, the local controllers adjust the local resource usages to optimize the utility of single application. The hierarchical control system considers all applications and coordinates all layers of grid architecture upon any changes. According to different time granularity, we adopt a different control scheme. The global control considers all applications and coordinates three layers of grid architecture in response to large system changes at coarse time granularity, while local control adapts a single application to small changes at fine granularity. This paper adopts utility-driven cross layer optimization for grid applications to find a system wide optimization and solves the cross-layer optimization by using pricing based decomposition. A set of hierarchical utility functions is used to measure the performance of the grid system that follows the system, group and application hierarchy. This paper uses total utility to measure the overall quality of grid system. The experiments are conducted to test the performance of the hierarchical control algorithms.

Efficient integration of fine-grained access control and resource brokering in grid

In this paper, we present a novel resource brokering service for grid systems which considers authorization policies of the grid nodes in the process of selecting the resources to be assigned to a request. We argue such an integration is needed to avoid scheduling requests onto resources the policies of which do not authorize their execution. Our service, implemented in Globus as a part of Monitoring and Discovery Service (MDS), is based on the concept of fine-grained access control (FGAC) which enables participating grid nodes to specify fine-grained policies concerning the conditions under which grid clients can access their resources. Since the process of evaluating authorization policies, in addition to checking the resource requirements, can be a potential bottleneck for a large scale grid, we also analyze the problem of the efficient evaluation of FGAC policies. In this context, we present GroupByRule, a novel method for policy organization and compare its performance with other strategies.

On improving resource utilization and system throughput of master slave job scheduling in heterogeneous systems

The rapid advances of network technologies shed light on many aspects of the practicability of large scale ubiquitous computing. Grid technology has been recognized as an efficient solution to coordinate large-scale shared resources and execute complex applications in heterogeneous network environments. The problem of resource management and task allocation has always been one of the main challenges. In this paper, we present an efficient task allocation strategy for distributing tasks onto computing nodes in the underlying heterogeneous networks. The contribution of the proposed technique is to minimize average turnaround time by dispatching tasks to processors with smallest communication ratio. System throughput could be also enhanced by dispersing processor idle time. The proposed technique can be applied to heterogeneous cluster systems as well as computational grid environments, in which the communication costs vary in different clusters. Experimental results show that the proposed scheme outperforms other previous algorithms in terms of throughput and turnaround time.

Heuristic solutions to resource allocation in grid computing: a natural approach

Grid computing connects heterogeneous resources to achieve the illusion of being a single available entity. Charging for these resources based on demand is often referred to as utility computing, where resource providers lease computing power with varying costs based on processing speed. Consumers using this resource have time and cost constraints associated with each job they submit. Determining the optimal way to divide the job among the available resources with regard to the time and cost constraints is tasked to the Grid Resource Broker (GRB). The GRB must use an optimization algorithm that returns an accurate result in a timely manner. The genetic algorithm and the simulated annealing algorithm can both be used to achieve this goal, although simulated annealing outperforms the genetic algorithm for use by the GRB. Determining optimal values for the variables used in each algorithm is often achieved through trial and error, and success depends upon the solution domain of the problem.

A user-friendly platform for developing and accessing grid services

This article presents an enhanced platform that provides a friendly environment of developing grid services and accessing grid services over Globus Toolkit 3 (GT3). This platform includes a class of functions for processing parameters input from a developer via GUI, a class of functions for generating files required for defining a grid service specified, and a class of functions for creating client program and facilitating accesses of the deployed services. As a result, the development and access of grid services requires less special expert knowledge of a developer at the server side and users at the client side, the efficiency of developing and accessing grid services can be improved. This paper describes our design ideas, necessary functions, and implementations. The comparisons with other related toolkits are given and the extended version of the platform on top of the web service environment rather than GT3.

IPBGA: a hybrid P2P based grid architecture by using information pool protocol

The current representatives of Grid systems are Globus and Web services, however, they have poor scalability and single point failure. It is these two factors which make the building of an improved P2P and grid hybrid framework for resource management and task schedule such a popular research topic. This paper differs from current research because it puts forward an Information Pool Based Grid Architecture (IPBGA), which is a real sense hybrid of P2P and grid instead of only introducing P2P methods into grid systems for resource management. Based on virtualizations, abstract physical resources and tasks to be, the information requests from resources for tasks and appeals from tasks for resources are upgraded as information services by using an information pool protocol (IPP). Thus, grid resource management and task scheduling are regarded as information matching by IPP which is adaptive to the heterogeneous, dynamic, and distributed characteristics of a grid system. Tri-Information Center (Tri-IC) and source ranking mechanisms are presented in IPP to improve robustness, prevent sybil attack, and to discourage free riding. Experiments and theory analysis show that the IPP of the IPBGA is more efficient and robust in dealing with information while both the bandwidth and process costs are less.

M-CASH: A real-time resource reclaiming algorithm for multiprocessor platforms

Resource reclaiming schemes are typically applied in reservation-based real-time uniprocessor systems to support efficient reclaiming and sharing of computational resources left unused by early completing tasks, improving the response times of aperiodic and soft tasks in the presence of overruns. In this paper, we introduce a novel and efficient reclaiming algorithm, named M-CASH, for multiprocessor platforms. M-CASH leverages the resource reservation approach offered by the Multiprocessor CBS server offering significant improvements. The correctness of the algorithm is formally proven and its performance is evaluated through extensive synthetic simulations.

Towards an evaluation framework for knowledge management systems

In this paper we develop an evaluation framework for Knowledge Management Systems (KMS). The framework builds on the theoretical foundations underlying organizational Knowledge Management (KM) to identify key KM activities and the KMS capabilities required to support each activity. These capabilities are then used to form a benchmark for evaluating KMS. Organizations selecting KMS can use the framework to identify gaps and overlaps in the extent to which the capabilities provided and utilized by their current KMS portfolio meet the KM needs of the organization. Other applications of the framework are also discussed.

A resource broker with an efficient network information model on grid environments

This paper describes a resource broker whose main function is to match available resources to user needs. The resource broker provides a uniform interface for accessing available and appropriate resources via user credentials. We also focus on providing approximate measurement models for network-related information using NWS for future scheduling and benchmarking. We first propose a network measurement model for gathering network-related information (including bandwidth, latency, forecasting, error rates, etc.) without generating excessive system overhead. Second, we constructed a grid platform using Globus Toolkit that integrates the resources of five schools in Taichung integrated grid environment resources (TIGER). The resource broker runs on top of TIGER. Therefore, it provides security and current information about available resources and serves as a link to the diverse systems available in the Grid.

Automatically wrapping legacy software into services: A grid case study

The computational grid is rapidly evolving into a service-oriented computing infrastructure that facilitates resource sharing for solving large-scale data and computationally intensive problems. Peer-to-peer (P2P) systems have emerged as an infrastructure enabling technologies for enhanced scalability and reliability in file sharing and content distribution. It is envisioned that P2P enabled service-oriented grid systems would virtualize various resources as services with high scalability and reliability. Many legacy software resources exist nowadays, but making them grid aware services for effective resource sharing has become an issue of vital importance. This paper presents GSLab, a toolkit for automatically wrapping legacy software into services that can be published, discovered and reused in grid environments. GSLab employs Sun Grid Engine (SGE) to enhance its performance in execution of wrapped services. Using GSLab, we have automatically wrapped a legacy computer animation rendering code written in C as a service that can be discovered and accessed in a SGE environment. The evaluation results show that the performance of GSLab improves with an increase in the number of computing nodes involved.

A grid based software architecture for delivery of adaptive and personalised learning experiences

This paper is centred on one of the main results of the ELeGI project, namely its software architecture for the delivery of personalised formal-learning experiences. The architecture has been designed and developed: (1) taking into account a general model for the personalisation of learning experiences, allowing us to obtain a solution that is flexible with respect to the pedagogies, and (2) on top of service oriented grid technologies, allowing us to obtain several advantages in the process of creation and delivery of personalised learning experience like, for instance, ubiquitous and seamless access to heterogeneous learning resources distributed over the network. In order to validate our result, the first prototype of the ELeGI architecture has been deployed on a virtual organisation consisting of three geographically distributed nodes. Each node of the VO provides services and learning resources that have been adopted in the creation and delivery of a personalised learning experience about the Torricelli’s law and based on the virtual scientific experiment model. The case of study has been successfully executed and has given us a proof of our assumptions related to the added value of the service oriented grid mainly in terms of: (1) capabilities to access educational resources distributed over the network, that is relevant in achieving the personalisation of learning experiences, and (2) high level of dynamicity and adaptiveness in the creation and delivery processes of a personalised learning experience.

Evolving strategy for a probabilistic game of imperfect information using genetic programming

We provide the complete record of methodology that let us evolve BrilliAnt, the winner of the Ant Wars contest. Ant Wars contestants are virtual ants collecting food on a grid board in the presence of a competing ant. BrilliAnt has been evolved through a competitive one-population coevolution using genetic programming and fitnessless selection. In this paper, we detail the evolutionary setup that lead to BrilliAnt’s emergence, assess its direct and indirect human-competitiveness, and describe the behavioral patterns observed in its strategy.

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Evaluating legacy assets in the context of migration to SOA

A key activity in the introduction of service oriented architecture (SOA) for an organization is to evaluate the suitability of existing assets for service orientation. We identify the core principles of SOA as the guide lines in evaluating the suitability of the existing assets. The existing metrics and guidelines that could be helpful in evaluating these principles are surveyed. This would benefit an organization in understanding the effort needed for migration and also to build proper services from the existing assets.

A grouped P2P network for scalable grid information services

Information services play a crucial role in grid environments in that the state information can be used to facilitate the discovery of resources and the services available to meet user requirements, and also to help tune the performance of a grid system. However, the large size and dynamic nature of the grid brings forth a number of challenges for information services. This paper presents PIndex, a grouped peer-to-peer network that can be used for scalable grid information services. PIndex builds on Globus MDS4, but introduces peer groups to dynamically split the large grid information search space into many small sections to enhance its scalability and resilience. PIndex is subsequently modeled with Colored Petri Nets for performance evaluation. The simulation results show that PIndex is scalable and resilient in dealing with a large number of peer nodes.

A taxonomy for resource discovery

Resource discovery systems become more and more important as distributed systems grow and as their pool of resources becomes more variable. As such, an increasing amount of networked systems provide a discovery service. This paper provides a taxonomy for resource discovery systems by defining their design aspects. This allows comparison of the designs of the deployed discovery services and is intended as an aid to system designers when selecting an appropriate mechanism. The surveyed systems are divided into four classes that are separately described. Finally, we identify a hiatus in the design space and point out genuinely distributed resource discovery systems that support dynamic and mobile resources and use attribute-based naming as a main direction for future research in this area.

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Report on the 2nd International Summer School on Network and Service Management (ISSNSM’08)

This report summarizes the 2nd International Summer School on Network and Service Management (ISSNSM’08), which was held at the Communication Systems Group (CSG) of the Department of Informatics (IFI), University of Zurich, Switzerland, on 2–6 June 2008. Supported by the European FP6 Network of Excellence for the Management of Internet Technologies and Complex Services (EMANICS), the ISSNSM presented within 5 days eight different topics, covering the areas of (1) security, (2) virtualization and simulations, and (3) network monitoring and management. All of these run for a full or half day, including a short theoretical introduction and larger practical lab course components, respectively.

Is emotion relevant to requirements engineering?

This viewpoint argues that the introduction of most computer-based system to an organization transforms the organization and changes the work patterns of the system’s users in the organization. These changes interact with the users’ values and beliefs and trigger emotional responses which are sometimes directed against the software system and its proponents. A requirements engineer must be aware of these emotions.

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An adaptive and trustworthy software testing framework on the grid

Grid computing, which is characterized by large-scale sharing and collaboration of dynamic distributed resources has quickly become a mainstream technology in distributed computing and is changing the traditional way of software development. In this article, we present a grid-based software testing framework for unit and integration test, which takes advantage of the large-scale and cost-efficient computational grid resources to establish a testbed for supporting automated software test in complex software applications. Within this software testing framework, a dynamic bag-of-tasks model using swarm intelligence is developed to adaptively schedule unit test cases. Various high-confidence computing mechanisms, such as redundancy, intermediate value checks, verification code injection, and consistency checks are employed to verify the correctness of each test case execution on the grid. Grid workflow is used to coordinate various test units for integration test. Overall, we expect that the grid-based software testing framework can provide efficient and trustworthy services to significantly accelerate the testing process with large-scale software testing.

Usage-based dynamic pricing of Web services for optimizing resource allocation

Web services technology is becoming an important technological trend in Web application development and integration. Based on open standards, such as SOAP, WSDL, and UDDI, Web services allow Web-based applications to communicate with each other through standardized XML messaging and to form loosely coupled distributed systems. Although the open feature of Web services benefits service providers in servicing consumers, the unlimited computing resources access of Web services to network bandwidth, storage throughput, and CPU time may lead to overexploitation of the resources when applications based on the Web services technology are widely accepted. Therefore, it is critical to optimize the operation of Web services, subject to the QoS requirements of service requests, to assure the total benefits of the service providers and the service consumers. This paper proposes a usage-based dynamic pricing approach to optimizing resource allocation of Web services in the principle of economics, and reports on a pilot implementation demonstrating the technical feasibility of the proposed approach.

Multimodal support to group dynamics

The complexity of group dynamics occurring in small group interactions often hinders the performance of teams. The availability of rich multimodal information about what is going on during the meeting makes it possible to explore the possibility of providing support to dysfunctional teams from facilitation to training sessions addressing both the individuals and the group as a whole. A necessary step in this direction is that of capturing and understanding group dynamics. In this paper, we discuss a particular scenario, in which meeting participants receive multimedia feedback on their relational behaviour, as a first step towards increasing self-awareness. We describe the background and the motivation for a coding scheme for annotating meeting recordings partially inspired by the Bales’ Interaction Process Analysis. This coding scheme was aimed at identifying suitable observable behavioural sequences. The study is complemented with an experimental investigation on the acceptability of such a service.

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