29,471 research outputs found

    Resource allocation and scheduling of multiple composite web services in cloud computing using cooperative coevolution genetic algorithm

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    In cloud computing, resource allocation and scheduling of multiple composite web services is an important and challenging problem. This is especially so in a hybrid cloud where there may be some low-cost resources available from private clouds and some high-cost resources from public clouds. Meeting this challenge involves two classical computational problems: one is assigning resources to each of the tasks in the composite web services; the other is scheduling the allocated resources when each resource may be used by multiple tasks at different points of time. In addition, Quality-of-Service (QoS) issues, such as execution time and running costs, must be considered in the resource allocation and scheduling problem. Here we present a Cooperative Coevolutionary Genetic Algorithm (CCGA) to solve the deadline-constrained resource allocation and scheduling problem for multiple composite web services. Experimental results show that our CCGA is both efficient and scalable

    Transparent Scheduling of Composite Web Services

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    Composite Web Services (CWS) aggregate multiple Web Services in one logical unit to accomplish a complex task (e.g. business process). This aggregation is achieved by defining a workflow that orchestrates the underlying Web Services in a manner consistent with the desired functionality. Since CWS can aggregate atomic and other CWS they foster the development of service layers and reuse of already existing functionality. An important issue in the deployment of services is their run-time performance under various loads. Due to the complex interactions of the underlying services, a CWS they can exhibit problematic and often difficult to predict behaviours in overload situations. This paper focuses on the use of request scheduling for improving CWS performance in overload situations. Different scheduling policies are investigated in regards to their effectiveness in helping with bulk arrivals

    Atomic service-based scheduling for web services composition

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    With the rapid development of Internet technologies and widespread of Internet applications, Web Services has become an important research issue of World Wide Web Consortium (W3C). In order to cope with various requirements from service users, services need to be thoroughly and precisely described, thus improvement needs to be made in describing services as more properties should be added to the current service description model based on OWL-ร, an ontology structure consisting of service profiles and operations. Semantics is widely considered as one of the core supplements, which is able to provide the metadata of services, so as to better match requirements with services in the service repository. On the other hand, Web Services has attracted people from various fields to perform relevant experiments on how to cope with users' requirements. Service providers tend to coordinate service implementation by means of interacting with available resources and reconstructing existing service modules. The integration of self-contained software components becomes a key step to meet service demands. This thesis makes contributions to current service description. The introduction of the term "Atomic Service" is not only considered to be a more refined service structure, but also serves as the fundamental component for all service modules. Based on this, the thesis will discuss issues including composition and scheduling, with the purpose of building interoperations among composable service units and setting up the mechanism of realising business goals with composite services under the guidance of the service scheduling language. This notion is illustrated in a demonstration system to justify the manageable interrelationship between service modules and the way of composition

    Workflow Partitioning and Deployment on the Cloud using Orchestra

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    Orchestrating service-oriented workflows is typically based on a design model that routes both data and control through a single point - the centralised workflow engine. This causes scalability problems that include the unnecessary consumption of the network bandwidth, high latency in transmitting data between the services, and performance bottlenecks. These problems are highly prominent when orchestrating workflows that are composed from services dispersed across distant geographical locations. This paper presents a novel workflow partitioning approach, which attempts to improve the scalability of orchestrating large-scale workflows. It permits the workflow computation to be moved towards the services providing the data in order to garner optimal performance results. This is achieved by decomposing the workflow into smaller sub workflows for parallel execution, and determining the most appropriate network locations to which these sub workflows are transmitted and subsequently executed. This paper demonstrates the efficiency of our approach using a set of experimental workflows that are orchestrated over Amazon EC2 and across several geographic network regions.Comment: To appear in Proceedings of the IEEE/ACM 7th International Conference on Utility and Cloud Computing (UCC 2014

    Business rule driven service competition.

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