91 research outputs found
Self-organising management of Grid environments
This paper presents basic concepts, architectural principles and algorithms for efficient resource and security management in cluster computing environments and the Grid. The work presented in this paper is funded by BTExacT and the EPSRC project SO-GRM (GR/S21939)
An Overview of a Grid Architecture for Scientific Computing
This document gives an overview of a Grid testbed architecture proposal for
the NorduGrid project. The aim of the project is to establish an inter-Nordic
testbed facility for implementation of wide area computing and data handling.
The architecture is supposed to define a Grid system suitable for solving data
intensive problems at the Large Hadron Collider at CERN. We present the various
architecture components needed for such a system. After that we go on to give a
description of the dynamics by showing the task flow
ULabGrid, an infrastructure to develop distant laboratories for undergrad students over a Grid
Nowadays, there is a big discussion about two different topics: how distance learning and the old fashioned learning can be improved
using the new technologies. In both cases, there are many collaborative
tools based on the web infrastructure such as e-mail, web discussing
groups, virtual campuses or audio and video conferences, that basically
give a way of exchanging information among the different groups involved in learning tasks, but very few of them have been thought to
help or to develop laboratory classes (labs). In this paper we describe a
GRID infrastructure (ULabGrid) that supports distant laboratories for
undergrad students.Peer Reviewe
DiPerF: an automated DIstributed PERformance testing Framework
We present DiPerF, a distributed performance testing framework, aimed at
simplifying and automating service performance evaluation. DiPerF coordinates a
pool of machines that test a target service, collects and aggregates
performance metrics, and generates performance statistics. The aggregate data
collected provide information on service throughput, on service "fairness" when
serving multiple clients concurrently, and on the impact of network latency on
service performance. Furthermore, using this data, it is possible to build
predictive models that estimate a service performance given the service load.
We have tested DiPerF on 100+ machines on two testbeds, Grid3 and PlanetLab,
and explored the performance of job submission services (pre WS GRAM and WS
GRAM) included with Globus Toolkit 3.2.Comment: 8 pages, 8 figures, will appear in IEEE/ACM Grid2004, November 200
A Multilevel Approach to Topology-Aware Collective Operations in Computational Grids
The efficient implementation of collective communiction operations has
received much attention. Initial efforts produced "optimal" trees based on
network communication models that assumed equal point-to-point latencies
between any two processes. This assumption is violated in most practical
settings, however, particularly in heterogeneous systems such as clusters of
SMPs and wide-area "computational Grids," with the result that collective
operations perform suboptimally. In response, more recent work has focused on
creating topology-aware trees for collective operations that minimize
communication across slower channels (e.g., a wide-area network). While these
efforts have significant communication benefits, they all limit their view of
the network to only two layers. We present a strategy based upon a multilayer
view of the network. By creating multilevel topology-aware trees we take
advantage of communication cost differences at every level in the network. We
used this strategy to implement topology-aware versions of several MPI
collective operations in MPICH-G2, the Globus Toolkit[tm]-enabled version of
the popular MPICH implementation of the MPI standard. Using information about
topology provided by MPICH-G2, we construct these multilevel topology-aware
trees automatically during execution. We present results demonstrating the
advantages of our multilevel approach by comparing it to the default
(topology-unaware) implementation provided by MPICH and a topology-aware
two-layer implementation.Comment: 16 pages, 8 figure
Security for Grid Services
Grid computing is concerned with the sharing and coordinated use of diverse
resources in distributed "virtual organizations." The dynamic and
multi-institutional nature of these environments introduces challenging
security issues that demand new technical approaches. In particular, one must
deal with diverse local mechanisms, support dynamic creation of services, and
enable dynamic creation of trust domains. We describe how these issues are
addressed in two generations of the Globus Toolkit. First, we review the Globus
Toolkit version 2 (GT2) approach; then, we describe new approaches developed to
support the Globus Toolkit version 3 (GT3) implementation of the Open Grid
Services Architecture, an initiative that is recasting Grid concepts within a
service oriented framework based on Web services. GT3's security implementation
uses Web services security mechanisms for credential exchange and other
purposes, and introduces a tight least-privilege model that avoids the need for
any privileged network service.Comment: 10 pages; 4 figure
GRIDKIT: Pluggable overlay networks for Grid computing
A `second generation' approach to the provision of Grid middleware is now emerging which is built on service-oriented architecture and web services standards and technologies. However, advanced Grid applications have significant demands that are not addressed by present-day web services platforms. As one prime example, current platforms do not support the rich diversity of communication `interaction types' that are demanded by advanced applications (e.g. publish-subscribe, media streaming, peer-to-peer interaction). In the paper we describe the Gridkit middleware which augments the basic service-oriented architecture to address this particular deficiency. We particularly focus on the communications infrastructure support required to support multiple interaction types in a unified, principled and extensible manner-which we present in terms of the novel concept of pluggable overlay networks
MPICH-G2: A Grid-Enabled Implementation of the Message Passing Interface
Application development for distributed computing "Grids" can benefit from
tools that variously hide or enable application-level management of critical
aspects of the heterogeneous environment. As part of an investigation of these
issues, we have developed MPICH-G2, a Grid-enabled implementation of the
Message Passing Interface (MPI) that allows a user to run MPI programs across
multiple computers, at the same or different sites, using the same commands
that would be used on a parallel computer. This library extends the Argonne
MPICH implementation of MPI to use services provided by the Globus Toolkit for
authentication, authorization, resource allocation, executable staging, and
I/O, as well as for process creation, monitoring, and control. Various
performance-critical operations, including startup and collective operations,
are configured to exploit network topology information. The library also
exploits MPI constructs for performance management; for example, the MPI
communicator construct is used for application-level discovery of, and
adaptation to, both network topology and network quality-of-service mechanisms.
We describe the MPICH-G2 design and implementation, present performance
results, and review application experiences, including record-setting
distributed simulations.Comment: 20 pages, 8 figure
- …