74 research outputs found
The Application of Cloud Computing to the Creation of Image Mosaics and Management of Their Provenance
We have used the Montage image mosaic engine to investigate the cost and
performance of processing images on the Amazon EC2 cloud, and to inform the
requirements that higher-level products impose on provenance management
technologies. We will present a detailed comparison of the performance of
Montage on the cloud and on the Abe high performance cluster at the National
Center for Supercomputing Applications (NCSA). Because Montage generates many
intermediate products, we have used it to understand the science requirements
that higher-level products impose on provenance management technologies. We
describe experiments with provenance management technologies such as the
"Provenance Aware Service Oriented Architecture" (PASOA).Comment: 15 pages, 3 figur
Comparing FutureGrid, Amazon EC2, and Open Science Grid for Scientific Workflows
Scientists have a number of computing infrastructures available to conduct their research, including grids and public or
private clouds. This paper explores the use of these cyberinfrastructures to execute scientific workflows, an important
class of scientific applications. It examines the benefits and drawbacks of cloud and grid systems using the case study
of an astronomy application. The application analyzes data from the NASA Kepler mission in order to compute
periodograms, which help astronomers detect the periodic dips in the intensity of starlight caused by exoplanets as they
transit their host star. In this paper we describe our experiences modeling the periodogram application as a scientific
workflow using Pegasus, and deploying it on the FutureGrid scientific cloud testbed, the Amazon EC2 commercial
cloud, and the Open Science Grid. We compare and contrast the infrastructures in terms of setup, usability, cost,
resource availability and performance
Reproducibility of scientific workflows execution using cloud-aware provenance (ReCAP)
© 2018, Springer-Verlag GmbH Austria, part of Springer Nature. Provenance of scientific workflows has been considered a mean to provide workflow reproducibility. However, the provenance approaches adopted so far are not applicable in the context of Cloud because the provenance trace lacks the Cloud information. This paper presents a novel approach that collects the Cloud-aware provenance and represents it as a graph. The workflow execution reproducibility on the Cloud is determined by comparing the workflow provenance at three levels i.e., workflow structure, execution infrastructure and workflow outputs. The experimental evaluation shows that the implemented approach can detect changes in the provenance traces and the outputs produced by the workflow
A Tale Of 160 Scientists, Three Applications, a Workshop, and a Cloud
The NASA Exoplanet Science Institute (NExScI) hosts the annual Sagan Workshops, thematic meetings aimed at introducing researchers to the latest tools and methodologies in exoplanet research. The theme of the Summer 2012 workshop, held from July 23 to July 27 at Caltech, was to explore the use of exoplanet light curves to study planetary system architectures and atmospheres. A major part of the workshop was to use hands-on sessions to instruct attendees in the use of three open source tools for the analysis of light curves, especially from the Kepler mission. Each hands-on session involved the 160 attendees using their laptops to follow step-by-step tutorials given by experts. One of the applications, PyKE, is a suite of Python tools designed to reduce and analyze Kepler light curves; these tools can be invoked from the Unix command line or a GUI in PyRAF. The Transit Analysis Package (TAP) uses Markov Chain Monte Carlo (MCMC) techniques to fit light curves under the Interactive Data Language (IDL) environment, and Transit Timing Variations (TTV) uses IDL tools and Java-based GUIs to confirm and detect exoplanets from timing variations in light curve fitting. Rather than attempt to run these diverse applications on the inevitable wide range of environments on attendees laptops, they were run instead on the Amazon Elastic Cloud 2 (EC2). The cloud offers features ideal for this type of short term need: computing and storage services are made available on demand for as long as needed, and a processing environment can be customized and replicated as needed. The cloud environment included an NFS file server virtual machine (VM), 20 client VMs for use by attendees, and a VM to enable ftp downloads of the attendees' results. The file server was configured with a 1 TB Elastic Block Storage (EBS) volume (network-attached storage mounted as a device) containing the application software and attendees home directories. The clients were configured to mount the applications and home directories from the server via NFS. All VMs were built with CentOS version 5.8. Attendees connected their laptops to one of the client VMs using the Virtual Network Computing (VNC) protocol, which enabled them to interact with a remote desktop GUI during the hands-on sessions. We will describe the mechanisms for handling security, failovers, and licensing of commercial software. In particular, IDL licenses were managed through a server at Caltech, connected to the IDL instances running on Amazon EC2 via a Secure Shell (ssh) tunnel. The system operated flawlessly during the workshop
Introducing the Vienna Platform for Elastic Processes
Resource-intensive tasks are playing an increasing role in business processes. The emergence of Cloud computing has enabled the deployment of such tasks onto resources sourced on-demand from Cloud providers. This has enabled so-called elastic processes that are able to dynamically adjust their resource usage to meet varying workloads. Traditional Business Process Management Systems (BPMSs) do not consider the needs of elastic processes such as monitoring facilities, tracking the current and future system landscape, reasoning about optimally utilizing resources given Quality of Service constraints, and executing necessary actions (e.g., start/stop servers, move services). This paper introduces ViePEP, a research BPMS capable of handling the aforementioned requirements of elastic processes
Intermittency of the noise emission in subsonic cold jets
International audienc
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