CRAID: Online RAID upgrades using dynamic hot data reorganization

Current algorithms used to upgrade RAID arrays typically require large amounts of data to be migrated, even those that move only the minimum amount of data required to keep a balanced data load. This paper presents CRAID, a self-optimizing RAID array that performs an online block reorganization of frequently used, long-term accessed data in order to reduce this migration even further. To achieve this objective, CRAID tracks frequently used, long-term data blocks and copies them to a dedicated partition spread across all the disks in the array. When new disks are added, CRAID only needs to extend this process to the new devices to redistribute this partition, thus greatly reducing the overhead of the upgrade process. In addition, the reorganized access patterns within this partition improve the array’s performance, amortizing the copy overhead and allowing CRAID to offer a performance competitive with traditional RAIDs. We describe CRAID’s motivation and design and we evaluate it by replaying seven real-world workloads including a file server, a web server and a user share. Our experiments show that CRAID can successfully detect hot data variations and begin using new disks as soon as they are added to the array. Also, the usage of a dedicated partition improves the sequentiality of relevant data access, which amortizes the cost of reorganizations. Finally, we prove that a full-HDD CRAID array with a small distributed partition (<1.28% per disk) can compete in performance with an ideally restriped RAID-5 and a hybrid RAID-5 with a small SSD cache.Peer ReviewedPostprint (published version

Photohadronic scenario in interpreting the February-March 2014 flare of 1ES 1011+496

The extraordinary multi-TeV flare from 1ES 1011 +496 during February-March 2014 was observed by MAGIC telescopes for 17 nights and the average spectrum of the whole period has a non-trivial shape. We have used the photohadronic model and a template EBL model to explain the average spectrum which fits well to the flare data. The spectral index $\alpha$ is the only free parameter in our model. We have also shown that the non-trivial nature of the spectrum is due to the change in the behavior of the optical depth above $\sim 600$ GeV $\gamma$-ray energy accompanied with the high SSC flux.Comment: 11 pages, 3 figures, LaTe

Improving OpenStack Swift interaction with the I/O stack to enable software defined storage

This paper analyses how OpenStack Swift, a distributed object storage service for a globally used middleware, interacts with the I/O subsystem through the Operating System. This interaction, which seems organised and clean on the middleware side, becomes disordered on the device side when using mechanical disk drives, due to the way threads are used internally to request data. We will show that only modifying the Swift threading model we achieve an 18% mean improvement in performance with objects larger than 512 KiB and obtain a similar performance with smaller objects. Compared to the original scenario, the performance obtained on both scenarios is obtained in a fair way: the bandwidth is shared equally between concurrently accessed objects. Moreover, this threading model allows us to apply techniques for Software Defined Storage (SDS). We show an implementation of a Bandwidth Differentiation technique that can control each data stream and that guarantees a high utilization of the device.The research leading to these results has received funding from the European Community under the IOStack (H2020-ICT-2014-7-1) project, by the Spanish Ministry of Economy and Competitiveness under the TIN2015-65316-P grant and by the Catalan Government under the 2014-SGR-1051 grant. To learn more about the IOStack H2020 project, please visit http:nnwww.iostack.eu.Peer ReviewedPostprint (author's final draft

Blazar origin of some IceCube events

Recently ANTARES collaboration presented a time dependent analysis to a selected number of flaring blazars to look for upward going muon events produced from the charge current interaction of the muon neutrinos. We use the same list of flaring blazars to look for possible positional correlation with the IceCube neutrino events. In the context of photohadronic model we propose that the neutrinos are produced within the nuclear region of the blazar where Fermi accelerated high energy protons interact with the background synchrotron/SSC photons. Although we found that some objects from the ANTARES list are within the error circles of few IceCube events, the statistical analysis shows that none of these sources have a significant correlation.Comment: Latex file, 6 pages, two columns, 1 Figur

Los gases de efecto invernadero: la problemática económica y la normatividad en la industria mexicana

89 páginas. Maestría en Economía.El presente trabajo de investigación pretende explicar bajo una perspectiva Schumpeteriana, como se presenta el problema de los Gases de Efecto Invernadero (GEI) y sus impacto en la industria mexicana, buscando una forma de de ver como la transferencia o innovación tecnológica podrían vincularse junto a la normatividad del país, para mitigar los efectos de estos gases, y sin embargo y como se ve en este trabajo, harán falta una mayor vinculación entre la industria y las acciones gubernamentales para frenar controlar y dar vías de solución a este problema de contaminación ambiental que no solo afecta a el nivel ambiental, si no a todos los niveles que conforman una sociedad, como los niveles económicos que es lo que nos importa demostrar en esta investigación.This research work aims to explain under a Schumpeteriana as presented the problem of Greenhouse Gas and its impact on Mexican industry, looking for a way to see how the transfer of technological innovation or could be linked together with the regulations of country, to mitigate the effects of these gases, however, and as shown in this paper, will require greater linkage between industry and government actions to curb control and give solutions to the problem of environmental pollution that not only the level environmental affects, if not all levels that make up a society, such as economic levels that is what is important to us to show in this investigation

Memorias del subsuelo: Exploración de la economía de los valores en el Chile actual

This article is an effort to state the value articulations which are upgrated and reproduced in the interpretations made by social forces on the current public Chilean reality. We will examine those values which, thus with less strong political content, are less a “political culture” than a normative background that articulate the will of a common political destiny. They are more values of the polis than of politics. In this sence, the comprehension of the site and the meaning of certain public fundamental values, like order, equalness, freedom, justice and progress; the effort to describe the relations between material realities and value constructions; the description of the most solid and fertil cultural characteristics in the Chilean symbolic life; they form the challenges that have been confronted in this document, which show a conservation of order out of sence, a significant fracture in the imaginaries of social order between the rich and the rest; besides a group of incipient transformations associated to the realm of consumption and enterpreneuring as predominating integrative forms in Chile nowadays.Este artículo constituye un esfuerzo por dar cuenta de las articulaciones valorativas que se actualizan y reproducen en las interpretaciones que los actores sociales realizan sobre la realidad pública chilena actual. Se trata de observar aquellos valores que, aun teniendo un fuerte contenido político, son menos una 'cultura política' que un trasfondo normativo que articula las voluntades de construcción del destino político común. Son los valores de la polis más que de la política. En este sentido, la comprensión del sitio y el significado de ciertos valores públicos fundamentales, como el orden, la igualdad, la libertad, la justicia y el progreso; el esfuerzo por describir las relaciones entre realidades materiales y construcciones valorativas; la descripción de las características culturales más sólidas y fértiles en la vida simbólica chilena; constituyen los desafíos que se han afrontado en este documento, que muestra una conservación del orden vacía de sentido, una fractura significativa en los imaginarios de orden social entre los ricos y el resto; además de un conjunto de transformaciones incipientes asociadas al predominio del consumo y el emprendimiento como formas integrativas predominantes en el Chile actual

Cognición, estereotipo, imaginario y fantasía en el proceso de aprehensión de la nueva realidad a través del léxico del castellano: los testimonios de los Cronistas de Indias

The Crónicas de Indias is a miscellaneous world with information about America colonization: letters, autobiographies, natural histories, which invite us to revisit the philology, where language, literature, history, anthropology fit equally. The works developed so far reached divergent conclusions. We have proposed to unite language, literature and, also, history and anthropology. All these texts are useful to refer their content to the penetration of the indigenous lexicon into the Castilian language -and vice versa-, with identity, cultural exchanges and understanding-representation-cognition of the world. We will systematize -from its heterogeneity- the data coming from the Chronicles marking six phases in the adaptation process, according to the lexicographical theory, which will culminate with the incorporation of the indigenous word into the Spanish lexicon (semasiological, onomasiological and cognitive fields). These testimonies show the very essence of linguistic cognition. It is noted that, first, each language is adapted to represent its environment reality. When a new reality appears, previously unknown, the problems begin: language is insufficient to apprehend it. Until reaching the specific autochthonous word, there will be multiple search attempts to adapt cognition and language, which will culminate with the incorporation of the borrowed word with the cognitive load that it possesses.Las Crónicas de Indias son un mundo misceláneo con información sobre la colonización de América: cartas, autobiografías, historias naturales, que nos invitan a revisitar la filología, donde caben por igual lengua, literatura, historia, antropología. Los trabajos desarrollados hasta ahora llegaron a conclusiones divergentes. Aquí se propone unir lengua, literatura y, también, historia y antropología. Todos estos textos resultan útiles para referir su contenido a la penetración del léxico indígena en la lengua castellana –y viceversa–, con intercambios identitarios, culturales y comprensión-representación-cognición del mundo. Sistematizaremos –desde su heterogeneidad– los datos provenientes de las Crónicas marcando seis fases en el proceso de adaptación, según la teoría lexicográfica, que culminarán con la incorporación del vocablo indígena al léxico español (campos semasiológico, onomasiológico y cognitivo). Lo que muestran estos testimonios es la esencia misma de la cognición lingüística. Se constata que, primeramente, cada lengua está adaptada para representar la realidad de su entorno. Cuando aparece una nueva realidad, antes ignota, comienzan los problemas: la lengua se muestra insuficiente para aprehenderla. Hasta llegar a la palabra específica autóctona, habrá múltiples intentos de búsqueda para adaptar cognición y lengua, que culminarán con la incorporación de la palabra prestada con la carga cognoscitiva que posee

GESTÃO DA INTERNACIONALIZACÃO NAS UNIVERSIDADES DA ASSOCIAÇÃO INTERNACIONAL DAS UNIVERSIDADES LASSALISTAS (IALU): ESTRUTURA E PESSOAS

Este artigo tem por objetivo demonstrar os desafios da gestão estratégica para a internacionalização da educação superior nas universidades da Internacional Association of Lasalian Universities (IALU). É parte do estudo desenvolvido sobre Modelos de Gestão Universitária do Mestrado em Educação do Unilasalle Canoas - Brasil. A metodologia baseia-se na proposta de Knight (2008), Higher Education in Turmoil: The Changing World of Internationalization e questionário aplicado junto à IALU. O referencial teórico ancora-se sobre a gestão da internacionalização da educação superior: (KNIGHT, 2008; TAYLOR, 2010, MARINGE & FOSKETT, 2010; STALLIVIERI, 2004). Os resultados apontam 2 categorias presentes na gestão estratégica para a internacionalização da educação superior da IALU: Existência de Estrutura e Pessoas Qualificadas; Ausência da Cultura Internacional