28,129 research outputs found
MorphoSys: efficient colocation of QoS-constrained workloads in the cloud
In hosting environments such as IaaS clouds, desirable application performance is usually guaranteed through the use of Service Level Agreements (SLAs), which specify minimal fractions of resource capacities that must be allocated for unencumbered use for proper operation. Arbitrary colocation of applications with different SLAs on a single host may result in inefficient utilization of the host’s resources. In this paper, we propose that periodic resource allocation and consumption models -- often used to characterize real-time workloads -- be used for a more granular expression of SLAs. Our proposed SLA model has the salient feature that it exposes flexibilities that enable the infrastructure provider to safely transform SLAs from one form to another for the purpose of achieving more efficient colocation. Towards that goal, we present MORPHOSYS: a framework for a service that allows the manipulation of SLAs to enable efficient colocation of arbitrary workloads in a dynamic setting. We present results from extensive trace-driven simulations of colocated Video-on-Demand servers in a cloud setting. These results show that potentially-significant reduction in wasted resources (by as much as 60%) are possible using MORPHOSYS.National Science Foundation (0720604, 0735974, 0820138, 0952145, 1012798
Review and analysis of networking challenges in cloud computing
Cloud Computing offers virtualized computing, storage, and networking resources, over the Internet, to organizations and individual users in a completely dynamic way. These cloud resources are cheaper, easier to manage, and more elastic than sets of local, physical, ones. This encourages customers to outsource their applications and services to the cloud. The migration of both data and applications outside the administrative domain of customers into a shared environment imposes transversal, functional problems across distinct platforms and technologies. This article provides a contemporary discussion of the most relevant functional problems associated with the current evolution of Cloud Computing, mainly from the network perspective. The paper also gives a concise description of Cloud Computing concepts and technologies. It starts with a brief history about cloud computing, tracing its roots. Then, architectural models of cloud services are described, and the most relevant products for Cloud Computing are briefly discussed along with a comprehensive literature review. The paper highlights and analyzes the most pertinent and practical network issues of relevance to the provision of high-assurance cloud services through the Internet, including security. Finally, trends and future research directions are also presented
'First Portal in a Storm': A Virtual Space for Transition Students
The lives of millennial students are epitomised by ubiquitous information, merged technologies, blurred social-study-work boundaries, multitasking and hyperlinked online interactions (Oblinger & Oblinger, 2005). These characteristics have implications for the design of online spaces that aim to provide virtual access to course materials, administrative processes and support information, all of which is required by students to steer a course through the storm of their transition university experience. Previously we summarised the challenges facing first year students (Kift & Nelson, 2005) and investigated their current online engagement patterns, which revealed three issues for consideration when designing virtual spaces (Nelson, Kift & Harper, 2005). In this paper we continue our examination of students’ interactions with online spaces by considering the perceptions and use of technology by millennial students as well as projections for managing the virtual learning environments of the future. The findings from this analysis are informed by our previous work to conceptualise and describe the architecture of a transition portal
Evolutionary Service Composition and Personalization Ecosystem for Elderly Care
Current demographic trends suggest that people are living longer, while
the ageing process entails many necessities, calling for care services tailored to
the individual senior’s needs and life style. Personalized provision of care
services usually involves a number of stakeholders, including relatives, friends,
caregivers, professional assistance organizations, enterprises, and other support
entities. Traditional Information and Communication Technology based care and
assistance services for the elderly have been mainly focused on the development
of isolated and generic services, considering a single service provider, and
excessively featuring a techno-centric approach.
In contrast, advances on collaborative networks for elderly care suggest the
integration of services from multiple providers, encouraging collaboration as a
way to provide better personalized services. This approach requires a support
system to manage the personalization process and allow ranking the {service,
provider} pairs.
An additional issue is the problem of service evolution, as individual’s care
needs are not static over time. Consequently, the care services need to evolve
accordingly to keep the elderly’s requirements satisfied. In accordance with these
requirements, an Elderly Care Ecosystem (ECE) framework, a Service
Composition and Personalization Environment (SCoPE), and a Service Evolution
Environment (SEvol) are proposed.
The ECE framework provides the context for the personalization and
evolution methods. The SCoPE method is based on the match between the
customer´s profile and the available {service, provider} pairs to identify suitable
services and corresponding providers to attend the needs. SEvol is a method to build an adaptive and evolutionary system based on the MAPE-K methodology
supporting the solution evolution to cope with the elderly's new life stages.
To demonstrate the feasibility, utility and applicability of SCoPE and SEvol,
a number of methods and algorithms are presented, and illustrative scenarios are
introduced in which {service, provider} pairs are ranked based on a
multidimensional assessment method. Composition strategies are based on
customer’s profile and requirements, and the evolutionary solution is
determined considering customer’s inputs and evolution plans.
For the ECE evaluation process the following steps are adopted: (i) feature
selection and software prototype development; (ii) detailing the ECE framework
validation based on applicability and utility parameters; (iii) development of a
case study illustrating a typical scenario involving an elderly and her care needs;
and (iv) performing a survey based on a modified version of the technology
acceptance model (TAM), considering three contexts: Technological,
Organizational and Collaborative environment
MORPHOSYS: efficient colocation of QoS-constrained workloads in the cloud
In hosting environments such as IaaS clouds, desirable application performance is usually guaranteed through the use of Service Level Agreements (SLAs), which specify minimal fractions of resource capacities that must be
allocated for use for proper operation. Arbitrary colocation of applications with different SLAs on a single host may result in inefficient utilization of the host’s resources. In this paper, we propose that periodic resource allocation and consumption models be used for a more granular expression of SLAs. Our proposed SLA model has the salient feature that it exposes flexibilities that enable the IaaS provider to safely transform SLAs from one form to another
for the purpose of achieving more efficient colocation. Towards that goal, we present MorphoSys: a framework for a service that allows the manipulation of SLAs to enable efficient colocation of workloads. We present results from extensive trace-driven simulations of colocated Video-on-Demand servers in a cloud setting. The results show that potentially-significant reduction in wasted resources (by as much as 60%) are possible using MorphoSys.First author draf
Emerging technologies for learning (volume 1)
Collection of 5 articles on emerging technologies and trend
- …