Cost-aware multi data-center bulk transfers in the cloud from a customer-side perspective

Many cloud applications (e.g., data backup and replication, video distribution) require dissemination of large volumes of data from a source data-center to multiple geographically distributed data-centers. Given the high costs of wide-area bandwidth, the overall cost of inter-data-center communication is a major concern in such scenarios. While previous works have focused on optimizing the costs of bulk transfer, most of them use the charging models of Internet service providers, typically based on the 95th percentile of bandwidth consumption. However, public Cloud Service Providers (CSP) follow very different models to charge their customers. First, the cost for transmission is flat and depends on the location of the source and receiver data-centers. Second, CSPs offer discounts once customer transfers exceed certain volume thresholds per data-center. We present a systematic framework, CloudMPcast, that exploits these two aspects of cloud pricing schemes. CloudMPcast constructs overlay distribution trees for bulk-data transfer that both optimizes dollar costs of distribution, and ensures end-to-end data transfer times are not affected. CloudMPCast monitors TCP throughputs between data-centers and only proposes alternative trees that respect original transfer times. After an extensive measurement study, the cost savings range from 10 to 60 percent for both Azure and EC2 infrastructures, which potentially translates to millions of dollars a year assuming realistic demandsThis material is based upon work supported in part by the National Science Foundation (NSF) under Award No.1162333, . J. L. Garc ıa-Dorado is thankful for the financial support of the Jos e Castillejo Program (CAS12/00057

Diseño e implementación de un sistema de almacenamiento para entornos Fog

Actualmente, el progreso está marcado por el rápido desarrollo de Internet y la computación en la nube. Estas tecnologías han permitido la gestión de información ubicuamente, permitiendo a las personas la posibilidad de acceder a sus datos desde cualquier sitio y en cualquier momento. En la actualidad existen multitud de servicios gratuitos de almacenamiento en la nube, ofreciendo a los usuarios un backup de sus archivos, la posibilidad de compartirlos y gestionarlos ellos mismos. Además, estas empresas ofrecen la posibilidad de aumentar el espacio de almacenamiento con precios muy reducidos. Con motivo del desarrollo en los últimos años de la nube y del Internet de las cosas (Internet of Things), surge el concepto de Fog Computing, un modelo en el que los datos y el procesamiento se concentran en los dispositivos al borde de la red en lugar de Cloud Computing. Debido a la evolución de Internet of Things, las aplicaciones demandan respuestas en tiempo real, lo que implica disminuir la latencia y un menor consumo de ancho de banda por la proximidad de los dispositivos. Es por ello por lo que surge la necesidad de desarrollar el concepto de Fog Computing En este sentido, en este trabajo de fin de máster se propone el desarrollo e implementación de un sistema de almacenamiento Fog similar a los ya existentes en la nube. En este sistema, un usuario comparte un archivo distribuyéndolo entre otros dispositivos cercanos, respetando en todo momento la privacidad del usuario y de sus archivos. Además se ha implementado un mecanismo de blockchain para almacenar el historial y los cambios de los archivos así como la ubicación de los documentos compartidos. De esta manera, se conoce en todo momento la información de cada archivo y cada servidor de forma segura, ya que un bloque de la cadena de bloques no puede ser modificado una vez añadido.Progress is determined by the fast development of Internet and cloud computing. These technologies have allowed the management of information ubiquitously, allowing people to access data from anywhere and at any time. Currently there are many storage services in the cloud, offering users backup for their files and the ability to share and manage them by themselves. In addition, these companies offer the possibility of increasing storage at very low prices. Due to the recent development of the cloud and the Internet of Things, the concept of Fog Computing emerges, like a model in which data and processing are located in the edge devices instead of Cloud Computed Due to the evolution of the Internet of Things, applications demand answers in real time, which means reducing latency and reducing bandwidth consumption due to the proximity of devices. For that reason emerges the need to develop the concept of Fog Computing. That is why this project is proposing the development and implementation of a Fog system, in which the user shares a file distributing it among other close devices, respecting at all times the privacy of the users and their files. Also, a blockchain mecanism has been implemented to store location, changes and records of the files. In this way, information of each file and each server is known any time in a safe way, since a block from the blockchain cannot be modified once added