925 research outputs found
Enabling Adaptive Grid Scheduling and Resource Management
Wider adoption of the Grid concept has led to an increasing amount of federated
computational, storage and visualisation resources being available to scientists and
researchers. Distributed and heterogeneous nature of these resources renders most of the
legacy cluster monitoring and management approaches inappropriate, and poses new
challenges in workflow scheduling on such systems. Effective resource utilisation monitoring
and highly granular yet adaptive measurements are prerequisites for a more efficient Grid
scheduler. We present a suite of measurement applications able to monitor per-process
resource utilisation, and a customisable tool for emulating observed utilisation models. We
also outline our future work on a predictive and probabilistic Grid scheduler. The research is
undertaken as part of UK e-Science EPSRC sponsored project SO-GRM (Self-Organising
Grid Resource Management) in cooperation with BT
Early aspects: aspect-oriented requirements engineering and architecture design
This paper reports on the third Early Aspects: Aspect-Oriented Requirements Engineering and Architecture Design Workshop, which has been held in Lancaster, UK, on March 21, 2004. The workshop included a presentation session and working sessions in which the particular topics on early aspects were discussed. The primary goal of the workshop was to focus on challenges to defining methodical software development processes for aspects from early on in the software life cycle and explore the potential of proposed methods and techniques to scale up to industrial applications
Handling High-Level Model Changes Using Search Based Software Engineering
Model-Driven Engineering (MDE) considers models as first-class artifacts during the software
lifecycle. The number of available tools, techniques, and approaches for MDE is increasing as its
use gains traction in driving quality, and controlling cost in evolution of large software systems.
Software models, defined as code abstractions, are iteratively refined, restructured, and evolved.
This is due to many reasons such as fixing defects in design, reflecting changes in requirements,
and modifying a design to enhance existing features.
In this work, we focus on four main problems related to the evolution of software models: 1) the
detection of applied model changes, 2) merging parallel evolved models, 3) detection of design
defects in merged model, and 4) the recommendation of new changes to fix defects in software
models.
Regarding the first contribution, a-posteriori multi-objective change detection approach has been
proposed for evolved models. The changes are expressed in terms of atomic and composite
refactoring operations. The majority of existing approaches detects atomic changes but do not
adequately address composite changes which mask atomic operations in intermediate models.
For the second contribution, several approaches exist to construct a merged model by
incorporating all non-conflicting operations of evolved models. Conflicts arise when the
application of one operation disables the applicability of another one. The essence of the problem
is to identify and prioritize conflicting operations based on importance and context – a gap in
existing approaches. This work proposes a multi-objective formulation of model merging that
aims to maximize the number of successfully applied merged operations.
For the third and fourth contributions, the majority of existing works focuses on refactoring at
source code level, and does not exploit the benefits of software design optimization at model
level. However, refactoring at model level is inherently more challenging due to difficulty in
assessing the potential impact on structural and behavioral features of the software system. This requires analysis of class and activity diagrams to appraise the overall system quality, feasibility,
and inter-diagram consistency. This work focuses on designing, implementing, and evaluating a
multi-objective refactoring framework for detection and fixing of design defects in software
models.Ph.D.Information Systems Engineering, College of Engineering and Computer ScienceUniversity of Michigan-Dearbornhttp://deepblue.lib.umich.edu/bitstream/2027.42/136077/1/Usman Mansoor Final.pdfDescription of Usman Mansoor Final.pdf : Dissertatio
HitFlow: A Dataflow Programming Model for Hybrid Distributed- and Shared-Memory Systems
Producción CientíficaDataflow programming consists in developing a program by describing its sequential stages and the interactions between them. The runtime systems supporting this kind of programming are responsible for exploiting the parallelism by concurrently executing the different stages as soon as their dependencies are met. In this paper we introduce a new parallel programming model and framework based on the dataflow paradigm. It presents a new combination of features that allows to easily map programs to shared or distributed memory, exploiting data locality and affinity to obtain the same performance than optimized coarse-grain MPI programs. These features include: It is a unique one-tier model that supports hybrid shared- and distributed-memory systems with the same abstractions; it can express activities arbitrarily linked, including non-nested cycles; it uses internally a distributed work-stealing mechanism to allow Multiple-Producer/Multiple-Consumer configurations; and it has a runtime mechanism for the reconfiguration of the dependences and communication channels which also allows the creation of task-to-task data affinities. We present an evaluation using examples of different classes of applications. Experimental results show that programs generated using this framework deliver good performance in hybrid distributed- and shared-memory environments, with a similar development effort as other dataflow programming models oriented to shared-memory.2019-01-01MICINN (Spain) and ERDF program of the European Union: HomProg-HetSys project (TIN2014-58876- P), PCAS project (TIN2017-88614-R), CAPAP-H6 (TIN2016-81840-REDT), and COST Program Action IC1305: Network for Sustainable Ultrascale Com- puting (NESUS). By Junta de Castilla y Le on, project PROPHET (VA082P17). And by the computing facilities of Extremadura Research Centre for Advanced Technologies (CETA- CIEMAT), funded by the European Regional Develop- ment Fund (ERDF). CETA-CIEMAT belongs to CIEMAT and the Govern- ment of Spain
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