Daniele D’Agostino

Hybrid Clouds brokering: Business opportunities, QoS and energy-saving issues

Abstract Hybrid Clouds couple the scalability offered by public Clouds with the greater control supplied by private ones. A (hybrid) Cloud broker acting as an intermediary between users and providers of public Cloud services, may support customers in the selection of the most suitable offers, optionally adding the provisioning of dedicated services with higher levels of quality. The paper presents a Cloud brokering algorithm delivering services with different level of non-functional requirements, to the private or public resources, on the basis of different scheduling criteria. With the objective of maximize user satisfaction and broker’s revenues, the algorithm pursues profit increases by reducing energy costs, through the adoption of energy saving mechanisms. A simulation model is used to evaluate performance in terms of broker’s revenue, user satisfaction and energy behavior of various allocation policies. Simulation results show that differences among policies depend on system loads and that the use of turn on and off techniques greatly improves energy savings at low and medium load rates.

A QoS-aware broker for hybrid clouds

Hybrid Clouds seems able to offer their customers with differentiate solutions capable of providing more and personalized guarantees with respect to the basic service availability generally supplied. In the context of an Italian research project aimed to transfer ICT advancements from research centers towards ICT SMEs, the paper focuses on the design of a brokering tool for hybrid clouds capable to adequately respond to specific Quality of Service (QoS) constraints. Aimed at satisfying the highest number of user requests while trying maximizing the profit of the private provider, in the context of a posted price economic model, the proposed brokering algorithm may apply different allocation policies, based on the reservation of a quota of private resources to high-level QoS applications.

An Online Parallel Algorithm for Remote Visualization of Isosurfaces

In this paper we present a parallel algorithm, implemented using MPICH, for isosurface extraction from volumetric data sets. The main contribution of this paper is in the analysis and performance improvements of the different phases of the isosurface production process including computation and output generation. The resulting algorithm is particularly well suited for online applications and for remote results visualization.

Heterogeneous architectures for computational intensive applications: A cost-effectiveness analysis

Current workstations can offer really amazing raw computational power, in the order of TFlops on a single machine equipped with multiple CPUs and accelerators, which means less than half a dollar for a GFlop. Such result can only be achieved with a massive parallelism of the computational devices, but unfortunately not every application is able to fully exploit them. In this paper we analyze the performances of some widely used, computational intensive, applications, like FFT, convolution and n-body simulation, comparing the performance of a multi-core cluster node, with or without the contribution of GPUs. We aim to provide clear measure of the benefit of a heterogeneous architecture, in terms of time and cost, with a stress on the technology adopted at different levels of the software stack for the application parallelization.

Load balancing and computing strategies in pipeline optimization for parallel visualization of 3D irregular meshes

Parallel visualization is assuming an increasing role in the deployment of Web and Grid based systems for scientific applications. The visualization process consists of a set of filters or components that are executed in a pipelined assembly that should be adaptively configured on the basis of user requirements, processing architecture and network characteristics. In this paper we focus our attention on the visualization of 3D irregular meshes produced by the interrogation of volumetric data using an isosurface extraction algorithm. We consider a simplified pipeline consisting of two components: isosurface extraction, and mesh simplification. We show that also in this simple case an in-deep analysis is necessary in order to optimize the whole pipeline. In fact different implementation and load balancing strategies are possible for each single component, but the whole pipeline optimization could be achieved combining non-optimal implementation of individual stages. Moreover the quality of the produced mesh should be considered in the selection of an adequate component implementation. The proposed analysis permits to point out trade-offs and algorithmic requirements that should be considered in the design of a complete visualization system for advanced Grid applications.

DRIHM(2US): An e-Science Environment for Hydrometeorological Research on High-Impact Weather Events

AbstractFrom 1970 to 2012, about 9,000 high-impact weather events were reported globally, causing the loss of 1.94 million lives and damage of

Science with the EXTraS Project: Exploring the X-Ray Transient and Variable Sky

2.4 trillion (U.S. dollars). The scientific community is called to action to improve the predictive ability of such events and communicate forecasts and associated risks both to affected populations and to those making decisions. At the heart of this challenge lies the ability to have easy access to hydrometeorological data and models and to facilitate the necessary collaboration between meteorologists, hydrologists, and computer science experts to achieve accelerated scientific advances. Two European Union (EU)-funded projects, Distributed Research Infrastructure for Hydro-Meteorology (DRIHM) and DRIHM to United States of America (DRIHM2US), sought to help address this challenge by developing a prototype e-science environment providing advanced end-to-end services (models, datasets, and postprocessing tools), with the aim of paving the way to a step change in how...

Results from DROXO - IV. EXTraS discovery of an X-ray flare from the Class I protostar candidate ISO-Oph 85

The EXTraS project (Exploring the X-ray Transient and variable Sky) will harvest the hitherto unexplored temporal domain information buried in the serendipitous data collected by the European Photon Imaging Camera (EPIC) instrument onboard the ESA XMM-Newton X-ray observatory since its launch. This will include a search for fast transients, as well as a search and characterization of variability (both periodic and aperiodic) in hundreds of thousands of sources spanning more than nine orders of magnitude in time scale and six orders of magnitude in flux. X-ray results will be complemented by multiwavelength characterization of new discoveries. Phenomenological classification of variable sources will also be performed. All our results will be made available to the community. A didactic program in selected High Schools in Italy, Germany and the UK will also be implemented. The EXTraS project (2014-2016), funded within the EU/FP7 framework, is carried out by a collaboration including INAF (Italy), IUSS (Italy), CNR/IMATI (Italy), University of Leicester (UK), MPE (Germany) and ECAP (Germany).

WS-PGRADE/gUSE in European Projects

X-ray emission from young stellar objects (YSOs) is a key ingredient in understanding star formation. For the early, protostellar (Class I) phase, a very limited (and controversial) quantity of X-ray results is available to date. Within the EXTraS (Exploring the X-ray Transient and variable Sky) project, we have discovered transient X-ray emission from a source whose counterpart is ISO-Oph 85, a strongly embedded YSO in the ρ Ophiuchi star-forming region. We extract an X-ray light curve for the flaring state, and determine the spectral parameters for the flare from XMM-Newton/EPIC data with a method based upon quantile analysis. We combine photometry from infrared to millimeter wavelengths from the literature with mid-IR Spitzer and unpublished submm Herschel photometry that we analysed for this work, and we describe the resulting spectral energy distribution (SED) with a set of precomputed models. The X-ray flare of ISO-Oph 85 lasted ~2500 s and is consistent with a highly-absorbed one-component thermal model (N_H = 1.0_(-0.5)^(+1.2) × 10^(23) cm^(-2) and kT= 1.15_(-0.65)^(+2.35) keV). The X-ray luminosity during the flare is log L_X [erg/s] = 31.1^(+2.0)_(-1.2); during quiescence we set an upper limit of log  L_X [erg/s] < 29.5. We do not detect other flares from this source. The submillimeter fluxes suggest that the object is a Class I protostar. We caution, however, that the offset between the Herschel and optical/infrared position is larger than that for other YSOs in the region, leaving some doubt on this association. To the best of our knowledge, this is the first X-ray flare from a YSO that has been recognised as a candidate Class I protostar via the analysis of its complete SED, including the submm bands that are crucial for detecting the protostellar envelope. This work shows how the analysis of the whole SED is fundamental to the classification of YSOs, and how the X-ray source detection techniques we have developed can open a new era in time-resolved analysis of the X-ray emission from stars.

Performance and Economic Evaluations in Adopting Low Power Architectures: A Real Case Analysis.

Besides core project partners, the SCI-BUS project also supported several external user communities in developing and setting up customized science gateways. The focus was on large communities typically represented by other European research projects. However, smaller local efforts with the potential of generalizing the solution to wider communities were also supported. This chapter gives an overview of support activities related to user communities external to the SCI-BUS project. A generic overview of such activities is provided, followed by the detailed description of three gateways developed in collaboration with European projects: the agINFRA Science Gateway for Workflows for agricultural research, the VERCE Science Gateway for seismology, and the DRIHM Science Gateway for weather research and forecasting.