29,471 research outputs found
Resource allocation and scheduling of multiple composite web services in cloud computing using cooperative coevolution genetic algorithm
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
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
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
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Improving the network transmission cost of differentiated web services
This paper investigates into the transmission cost of web services related messages which is affected by network
latency. Web services enable seamless interaction and integration of e-business applications. Web services contain a
collection of operations so as to interact with outside world over the Internet through XML messaging. Though XML
effectively describe message related information and is fairly human readable, it badly affects the performance of Web
services in terms of transmission cost, processing cost, and so on. This paper aims to minimize network latency of message
communication of Web services by employing pre-emptive resume scheduling. Fundamental principle of this approach is the
provision of preferential treatment to some messages as compared to others. This approach assigns different priorities to
distinct classes of messages given the fact that some messages may tolerate longer delays than others. For instance, shorter
messages may be given higher priority than longer messages, or the Web service provider may give higher priority to the
messages of paying subscribers
Workflow Partitioning and Deployment on the Cloud using Orchestra
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
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