446 research outputs found
gLite Workload Management System Performance Measurements
In this paper an introduction to the gLite Grid middleware and one of its most important components, Workload Management System (WMS), responsible for management of user jobs is given.Useful performance metrics of gLite WMS are defined from a Grid application point of view, and preliminary results of performance measurements are presented and briefly analyzed
ScotGrid: Providing an Effective Distributed Tier-2 in the LHC Era
ScotGrid is a distributed Tier-2 centre in the UK with sites in Durham,
Edinburgh and Glasgow. ScotGrid has undergone a huge expansion in hardware in
anticipation of the LHC and now provides more than 4MSI2K and 500TB to the LHC
VOs. Scaling up to this level of provision has brought many challenges to the
Tier-2 and we show in this paper how we have adopted new methods of organising
the centres, from fabric management and monitoring to remote management of
sites to management and operational procedures, to meet these challenges. We
describe how we have coped with different operational models at the sites,
where Glagsow and Durham sites are managed "in house" but resources at
Edinburgh are managed as a central university resource. This required the
adoption of a different fabric management model at Edinburgh and a special
engagement with the cluster managers. Challenges arose from the different job
models of local and grid submission that required special attention to resolve.
We show how ScotGrid has successfully provided an infrastructure for ATLAS and
LHCb Monte Carlo production. Special attention has been paid to ensuring that
user analysis functions efficiently, which has required optimisation of local
storage and networking to cope with the demands of user analysis. Finally,
although these Tier-2 resources are pledged to the whole VO, we have
established close links with our local physics user communities as being the
best way to ensure that the Tier-2 functions effectively as a part of the LHC
grid computing framework..Comment: Preprint for 17th International Conference on Computing in High
Energy and Nuclear Physics, 7 pages, 1 figur
LOGGING AND BOOKKEEPING, TROUBLESHOOTING GUIDE
LOGGING AND BOOKKEEPING – TROUBLESHOOTING GUID
The Locus Algorithm III: A Grid Computing system to generate catalogues of optimised pointings for Differential Photometry
This paper discusses the hardware and software components of the Grid
Computing system used to implement the Locus Algorithm to identify optimum
pointings for differential photometry of 61,662,376 stars and 23,799 quasars.
The scale of the data, together with initial operational assessments demanded a
High Performance Computing (HPC) system to complete the data analysis. Grid
computing was chosen as the HPC solution as the optimum choice available within
this project. The physical and logical structure of the National Grid computing
Infrastructure informed the approach that was taken. That approach was one of
layered separation of the different project components to enable maximum
flexibility and extensibility
Proxy dynamic delegation in grid gateway
Nowadays one of the main obstacles the research comes up against is the
difficulty in accessing the required computational resources. Grid is able to
offer the user a wide set of resources, even if they are often too hard to
exploit for non expert end user. Use simplification has today become a common
practice in the access and utilization of Cloud, Grid, and data center
resources. With the launch of L-GRID gateway, we introduced a new way to deal
with Grid portals. L-GRID is an extremely light portal developed in order to
access the EGI Grid infrastructure via Web, allowing users to submit their jobs
from whatever Web browser in a few minutes, without any knowledge about the
underlying Grid infrastructure.Comment: 6 page
Logging and bookkeeping, Administrator's guide
Logging and Bookkeeping (LB for short) is a Grid service that keeps a short-term trace of Grid jobs as they are processed by individual Grid component
A NeISS collaboration to develop and use e-infrastructure for large-scale social simulation
The National e-Infrastructure for Social Simulation (NeISS) project is focused on
developing e-Infrastructure to support social simulation research. Part of NeISS aims to
provide an interface for running contemporary dynamic demographic social simulation
models as developed in the GENESIS project. These GENESIS models operate at the
individual person level and are stochastic. This paper focuses on support for a simplistic
demographic change model that has a daily time steps, and is typically run for a number
of years.
A portal based Graphical User Interface (GUI) has been developed as a set
of standard portlets. One portlet is for specifying model parameters and setting a
simulation running. Another is for comparing the results of different simulation runs.
Other portlets are for monitoring submitted jobs and for interfacing with an archive of
results. A layer of programs enacted by the portlets stage data in and submit jobs to a
Grid computer which then runs a specific GENESIS model program executable. Once a
job is submitted, some details are communicated back to a job monitoring portlet. Once
the job is completed, results are stored and made available for download and further
processing. Collectively we call the system the Genesis Simulator.
Progress in the development of the Genesis Simulator was presented at the UK e-
Science All Hands Meeting in September 2011 by way of a video based demonstration
of the GUI, and an oral presentation of a working paper. Since then, an automated
framework has been developed to run simulations for a number of years in yearly time
steps. The demographic models have also been improved in a number of ways. This
paper summarises the work to date, presents some of the latest results and considers the
next steps we are planning in this work
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