3,646 research outputs found
User-centric Adaptation Analysis of Multi-tenant Services
Multi-tenancy is a key pillar of cloud services. It allows different users to share computing and virtual
resources transparently, meanwhile guaranteeing substantial cost savings. Due to the tradeoff between
scalability and customization, one of the major drawbacks of multi-tenancy is limited configurability. Since
users may often have conflicting configuration preferences, offering the best user experience is an open
challenge for service providers. In addition, the users, their preferences, and the operational environment
may change during the service operation, thus jeopardizing the satisfaction of user preferences. In this
article, we present an approach to support user-centric adaptation of multi-tenant services. We describe
how to engineer the activities of the Monitoring, Analysis, Planning, Execution (MAPE) loop to support
user-centric adaptation, and we focus on adaptation analysis. Our analysis computes a service configuration
that optimizes user satisfaction, complies with infrastructural constraints, and minimizes reconfiguration
obtrusiveness when user- or service-related changes take place. To support our analysis, we model multitenant
services and user preferences by using feature and preference models, respectively. We illustrate our
approach by utilizing different cases of virtual desktops. Our results demonstrate the effectiveness of the
analysis in improving user preferences satisfaction in negligible time.Ministerio de Economía y Competitividad TIN2012-32273Junta de Andalucía P12--TIC--1867Junta de Andalucía TIC-590
Orthogonal variability modeling to support multi-cloud application configuration
Cloud service providers benefit from a vast majority of customers due to variability and making profit from commonalities between the cloud services that they provide. Recently, application configuration dimensions has been increased dramatically due to multi-tenant, multi-device and multi-cloud paradigm. This challenges the configuration and customization of cloud-based software that are typically offered as a service due to the intrinsic variability. In this paper, we present a model-driven approach based on variability models originating from the software product line community to handle such multi-dimensional variability in the cloud. We exploit orthogonal variability models to systematically manage and create tenant-specific configuration and customizations. We also demonstrate how such variability models can be utilized to take into account the already deployed application parts to enable harmonized deployments for new tenants in a multi-cloud setting. The approach considers application functional and non-functional requirements to provide a set of valid multi-cloud configurations. We illustrate our approach through a case study
Software-Defined Cloud Computing: Architectural Elements and Open Challenges
The variety of existing cloud services creates a challenge for service
providers to enforce reasonable Software Level Agreements (SLA) stating the
Quality of Service (QoS) and penalties in case QoS is not achieved. To avoid
such penalties at the same time that the infrastructure operates with minimum
energy and resource wastage, constant monitoring and adaptation of the
infrastructure is needed. We refer to Software-Defined Cloud Computing, or
simply Software-Defined Clouds (SDC), as an approach for automating the process
of optimal cloud configuration by extending virtualization concept to all
resources in a data center. An SDC enables easy reconfiguration and adaptation
of physical resources in a cloud infrastructure, to better accommodate the
demand on QoS through a software that can describe and manage various aspects
comprising the cloud environment. In this paper, we present an architecture for
SDCs on data centers with emphasis on mobile cloud applications. We present an
evaluation, showcasing the potential of SDC in two use cases-QoS-aware
bandwidth allocation and bandwidth-aware, energy-efficient VM placement-and
discuss the research challenges and opportunities in this emerging area.Comment: Keynote Paper, 3rd International Conference on Advances in Computing,
Communications and Informatics (ICACCI 2014), September 24-27, 2014, Delhi,
Indi
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