1,136 research outputs found
Resource provisioning in Science Clouds: Requirements and challenges
Cloud computing has permeated into the information technology industry in the
last few years, and it is emerging nowadays in scientific environments. Science
user communities are demanding a broad range of computing power to satisfy the
needs of high-performance applications, such as local clusters,
high-performance computing systems, and computing grids. Different workloads
are needed from different computational models, and the cloud is already
considered as a promising paradigm. The scheduling and allocation of resources
is always a challenging matter in any form of computation and clouds are not an
exception. Science applications have unique features that differentiate their
workloads, hence, their requirements have to be taken into consideration to be
fulfilled when building a Science Cloud. This paper will discuss what are the
main scheduling and resource allocation challenges for any Infrastructure as a
Service provider supporting scientific applications
High-Performance Cloud Computing: A View of Scientific Applications
Scientific computing often requires the availability of a massive number of
computers for performing large scale experiments. Traditionally, these needs
have been addressed by using high-performance computing solutions and installed
facilities such as clusters and super computers, which are difficult to setup,
maintain, and operate. Cloud computing provides scientists with a completely
new model of utilizing the computing infrastructure. Compute resources, storage
resources, as well as applications, can be dynamically provisioned (and
integrated within the existing infrastructure) on a pay per use basis. These
resources can be released when they are no more needed. Such services are often
offered within the context of a Service Level Agreement (SLA), which ensure the
desired Quality of Service (QoS). Aneka, an enterprise Cloud computing
solution, harnesses the power of compute resources by relying on private and
public Clouds and delivers to users the desired QoS. Its flexible and service
based infrastructure supports multiple programming paradigms that make Aneka
address a variety of different scenarios: from finance applications to
computational science. As examples of scientific computing in the Cloud, we
present a preliminary case study on using Aneka for the classification of gene
expression data and the execution of fMRI brain imaging workflow.Comment: 13 pages, 9 figures, conference pape
Challenges and complexities in application of LCA approaches in the case of ICT for a sustainable future
In this work, three of many ICT-specific challenges of LCA are discussed.
First, the inconsistency versus uncertainty is reviewed with regard to the
meta-technological nature of ICT. As an example, the semiconductor technologies
are used to highlight the complexities especially with respect to energy and
water consumption. The need for specific representations and metric to
separately assess products and technologies is discussed. It is highlighted
that applying product-oriented approaches would result in abandoning or
disfavoring of new technologies that could otherwise help toward a better
world. Second, several believed-untouchable hot spots are highlighted to
emphasize on their importance and footprint. The list includes, but not limited
to, i) User Computer-Interfaces (UCIs), especially screens and displays, ii)
Network-Computer Interlaces (NCIs), such as electronic and optical ports, and
iii) electricity power interfaces. In addition, considering cross-regional
social and economic impacts, and also taking into account the marketing nature
of the need for many ICT's product and services in both forms of hardware and
software, the complexity of End of Life (EoL) stage of ICT products,
technologies, and services is explored. Finally, the impact of smart management
and intelligence, and in general software, in ICT solutions and products is
highlighted. In particular, it is observed that, even using the same
technology, the significance of software could be highly variable depending on
the level of intelligence and awareness deployed. With examples from an
interconnected network of data centers managed using Dynamic Voltage and
Frequency Scaling (DVFS) technology and smart cooling systems, it is shown that
the unadjusted assessments could be highly uncertain, and even inconsistent, in
calculating the management component's significance on the ICT impacts.Comment: 10 pages. Preprint/Accepted of a paper submitted to the ICT4S
Conferenc
Scientific Workflow Applications on Amazon EC2
The proliferation of commercial cloud computing providers has generated
significant interest in the scientific computing community. Much recent
research has attempted to determine the benefits and drawbacks of cloud
computing for scientific applications. Although clouds have many attractive
features, such as virtualization, on-demand provisioning, and "pay as you go"
usage-based pricing, it is not clear whether they are able to deliver the
performance required for scientific applications at a reasonable price. In this
paper we examine the performance and cost of clouds from the perspective of
scientific workflow applications. We use three characteristic workflows to
compare the performance of a commercial cloud with that of a typical HPC
system, and we analyze the various costs associated with running those
workflows in the cloud. We find that the performance of clouds is not
unreasonable given the hardware resources provided, and that performance
comparable to HPC systems can be achieved given similar resources. We also find
that the cost of running workflows on a commercial cloud can be reduced by
storing data in the cloud rather than transferring it from outside
Infrastructure Specifications
This document presents the computing infrastructure deployed in the context of StratusLab project, details the configuration of the computing resources used and the commitments made from the project partners to contribute with computing resources in the project. During the first months of operation this infrastructure has already been significantly exploited to deliver the first results towards the project's goals. The OpenNebula virtual management software has been used to install private clouds on different OS platforms. Two pre-production grid sites have been deployed in the private cloud and are used to test the implications of providing grid services in cloud environments. Experience from the deployment and operation of the above sites will help us identify the required tools and procedures for offering grid production sites over computing clouds. Finally the document presents related work, relevant to infrastructure operations, taking place in other projects and initiatives
High availability using virtualization
High availability has always been one of the main problems for a data center.
Till now high availability was achieved by host per host redundancy, a highly
expensive method in terms of hardware and human costs. A new approach to the
problem can be offered by virtualization. Using virtualization, it is possible
to achieve a redundancy system for all the services running on a data center.
This new approach to high availability allows to share the running virtual
machines over the servers up and running, by exploiting the features of the
virtualization layer: start, stop and move virtual machines between physical
hosts. The system (3RC) is based on a finite state machine with hysteresis,
providing the possibility to restart each virtual machine over any physical
host, or reinstall it from scratch. A complete infrastructure has been
developed to install operating system and middleware in a few minutes. To
virtualize the main servers of a data center, a new procedure has been
developed to migrate physical to virtual hosts. The whole Grid data center
SNS-PISA is running at the moment in virtual environment under the high
availability system. As extension of the 3RC architecture, several storage
solutions have been tested to store and centralize all the virtual disks, from
NAS to SAN, to grant data safety and access from everywhere. Exploiting
virtualization and ability to automatically reinstall a host, we provide a sort
of host on-demand, where the action on a virtual machine is performed only when
a disaster occurs.Comment: PhD Thesis in Information Technology Engineering: Electronics,
Computer Science, Telecommunications, pp. 94, University of Pisa [Italy
Automated tools and techniques for distributed Grid Software: Development of the testbed infrastructure
Grid technology is becoming more and more important as the new paradigm for sharing computational resources across different organizations in a secure way. The great powerfulness of this solution, requires the definition of a generic stack of services and protocols and this is the scope of the different Grid initiatives. As a result of international collaborations for its development, the Open Grid Forum created the Open Grid Services Architecture (OGSA) which aims to define the common set of services that will enable interoperability across the different implementations. This master thesis has been developed in this framework, as part of the two European-funded projects ETICS and OMII-Europe. The main objective is to contribute to the design and maintenance of large distributed development projects with the automated tool that enables to implement Software Engineering techniques oriented to achieve an acceptable level of quality at the release process. Specifically, this thesis develops the testbed concept as the virtual production-like scenario where to perform compliance tests. As proof of concept, the OGSA Basic Execution Service has been chosen in order to implement and execute conformance tests within the ETICS automated testbed framework
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