Person: Núñez Covarrubias, Alberto
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First Name
Alberto
Last Name
Núñez Covarrubias
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Informática
Department
Sistemas Informáticos y Computación
Area
Lenguajes y Sistemas Informáticos
Identifiers
5 results
Search Results
Now showing 1 - 5 of 5
Item Profiling SLAs for cloud system infrastructures and user interactions(PeerJ Computer Science, 2021) Bernal, Adrián; Valero, Valentín; Cambronero, M. Emilia; Núñez Covarrubias, Alberto; Cerro Cañizares, PabloCloud computing has emerged as a cutting-edge technology which is widely used by both private and public institutions, since it eliminates the capital expense of buying, maintaining, and setting up both hardware and software. Clients pay for the services they use, under the so-called Service Level Agreements (SLAs), which are the contracts that establish the terms and costs of the services. In this paper, we propose the CloudCost UML profile, which allows the modeling of cloud architectures and the users’ behavior when they interact with the cloud to request resources. We then investigate how to increase the profits of cloud infrastructures by using price schemes. For this purpose, we distinguish between two types of users in the SLAs: regular and high-priority users. Regular users do not require a continuous service, so they can wait to be attended to. In contrast, high-priority users require a constant and immediate service, so they pay a greater price for their services. In addition, a computer-aided design tool, called MSCC (Modeling SLAs Cost Cloud), has been implemented to support the CloudCost profile, which enables the creation of specific cloud scenarios, as well as their edition and validation. Finally, we present a complete case study to illustrate the applicability of the CloudCost profile, thus making it possible to draw conclusions about how to increase the profits of the cloud infrastructures studied by adjusting the different cloud parameters and the resource configuration.Item Evaluating cloud interactions with costs and SLAs(The Journal of Supercomputing, 2021) Bernal, Adrián; Cambronero, M. Emilia; Núñez Covarrubias, Alberto; Cerro Cañizares, Pablo; Valero, ValentínIn this paper, we investigate how to improve the profits in cloud infrastructures by using price schemes and analyzing the user interactions with the cloud provider. For this purpose, we consider two different types of client behavior, namely regular and high-priority users. Regular users do not require a continuous service, and they can wait to be attended to. In contrast, high-priority users require a continuous service, e.g., a 24/7 service, and usually need an immediate answer to any request. A complete framework has been implemented, which includes a UML profile that allows us to define specific cloud scenarios and the automatic transformations to produce the code for the cloud simulations in the Simcan2Cloud simulator. The engine of Simcan2Cloud has also been modified by adding specific SLAs and price schemes. Finally, we present a thorough experimental study to analyze the performance results obtained from the simulations, thus making it possible to draw conclusions about how to improve the cloud profit for the cloud studied by adjusting the different parameters and resource configuration.Item A Framework for Modeling Cloud Infrastructures and User Interactions(IEEE Access, 2019) Bernal, Adrián; Cambronero, M. Emilia; Valero, Valentín; Núñez Covarrubias, Alberto; Cerro Cañizares, PabloNowadays, cloud computing technologies are commonly used both by the public and private institutions, so as to save money and computing efforts, by using a network of remote servers hosted on the Internet to manage their services. Thus, cloud clients must interact with cloud providers in order to make use of the services deployed in the cloud, and the cloud infrastructure must be designed taking into account both the physical devices and equipment required (racks, switches, and so on) and also the user demands, expressed in terms of the services they need. This paper focuses on this latter aspect, in which we analyze how cloud clients interact with a cloud provider, providing a Unified Modeling Language-based framework to model a cloud system, including the underlying infrastructure, the user resource requirements, and their interactions with the cloud provider.Item Simcan2Cloud: a discrete-event-based simulator for modelling and simulating cloud computing infrastructures(Journal of Cloud Computing, 2023) Cerro Cañizares, Pablo; Núñez Covarrubias, Alberto; Bernal, Adrián; Cambronero, M. Emilia; Barker, AdamCloud computing is an evolving paradigm whose adoption has been increasing over the last few years. This fact has led to the growth of the cloud computing market, together with fierce competition for the leading market share, with an increase in the number of cloud service providers. Novel techniques are continuously being proposed to increase the cloud service provider’s profitability. However, only those techniques that are proven not to hinder the service agreements are considered for production clouds. Analysing the expected behaviour and performance of the cloud infrastructure is challenging, as the repeatability and reproducibility of experiments on these systems are made difficult by the large number of users concurrently accessing the infrastructure. To this, must be added the complications of using different provisioning policies, managing several workloads, and applying different resource configurations. Therefore, in order to alleviate these issues, we present Simcan2Cloud, a discrete-event-based simulator for modelling and simulating cloud computing environments. Simcan2Cloud focuses on modelling and simulating the behaviour of the cloud provider with a high level of detail, where both the cloud infrastructure and the interactions of the users with the cloud are integrated in the simulated scenarios. For this purpose, Simcan2Cloud supports different resource allocation policies, service level agreements (SLAs), and an intuitive and complete API for including new management policies. Finally, a thorough experimental study to measure the suitability and applicability of Simcan2Cloud, using both real-world traces and synthetic workloads, is presented.Item Improving cloud architectures using UML profiles and M2T transformation techniques(The Journal of Supercomputing, 2019) Bernal, Adrián; Cambronero, M. Emilia; Núñez Covarrubias, Alberto; Cerro Cañizares, Pablo; Valero, ValentínIn this paper, we present an approach with the goal to improve the underlying architecture of cloud systems. For this, we propose UML2Cloud, a framework targeted at modeling and checking cloud systems. The main core of UML2Cloud uses UML profiles to capture the main elements of a cloud system including, among other elements, its underlying architecture and the interaction with clients. Additionally, UML2Cloud uses Model-to-Text transformation techniques to automatically generate configuration documents representing complex cloud scenarios. In this work, we use these documents as input for a cloud simulation tool, called Simcan2Cloud, to simulate the behavior of different systems. Thus, the analysis of the performance results obtained from the simulations allows us to draw some conclusions about how to improve the efficiency of the studied clouds by adjusting the hardware resource configuration.