69 research outputs found
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
Scientific Workflow Scheduling for Cloud Computing Environments
The scheduling of workflow applications consists of assigning their tasks to computer resources to fulfill a final goal such as minimizing total workflow execution time. For this reason, workflow scheduling plays a crucial role in efficiently running experiments. Workflows often have many discrete tasks and the number of different task distributions possible and consequent time required to evaluate each configuration quickly becomes prohibitively large. A proper solution to the scheduling problem requires the analysis of tasks and resources, production of an accurate environment model and, most importantly, the adaptation of optimization techniques. This study is a major step toward solving the scheduling problem by not only addressing these issues but also optimizing the runtime and reducing monetary cost, two of the most important variables. This study proposes three scheduling algorithms capable of answering key issues to solve the scheduling problem. Firstly, it unveils BaRRS, a scheduling solution that exploits parallelism and optimizes runtime and monetary cost. Secondly, it proposes GA-ETI, a scheduler capable of returning the number of resources that a given workflow requires for execution. Finally, it describes PSO-DS, a scheduler based on particle swarm optimization to efficiently schedule large workflows. To test the algorithms, five well-known benchmarks are selected that represent different scientific applications. The experiments found the novel algorithms solutions substantially improve efficiency, reducing makespan by 11% to 78%. The proposed frameworks open a path for building a complete system that encompasses the capabilities of a workflow manager, scheduler, and a cloud resource broker in order to offer scientists a single tool to run computationally intensive applications
Software development in the post-PC era : towards software development as a service
PhD ThesisEngineering software systems is a complex task which involves various stakeholders
and requires planning and management to succeed. As the role of software in our daily
life is increasing, the complexity of software systems is increasing. Throughout the
short history of software engineering as a discipline, the development practises and
methods have rapidly evolved to seize opportunities enabled by new technologies
(e.g., the Internet) and to overcome economical challenges (e.g., the need for cheaper
and faster development).
Today, we are witnessing the Post-PC era. An era which is characterised by mobility and
services. An era which removes organisational and geographical boundaries. An era
which changes the functionality of software systems and requires alternative methods
for conceiving them.
In this thesis, we envision to execute software development processes in the cloud.
Software processes have a software production aspect and a management aspect. To
the best of our knowledge, there are no academic nor industrial solutions supporting the
entire software development process life-cycle(from both production and management
aspects and its tool-chain execution in the cloud.
Our vision is to use the cloud economies of scale and leverage Model-Driven Engineering
(MDE) to integrate production and management aspects into the development
process. Since software processes are seen as workflows, we investigate using existing
Workflow Management Systems to execute software processes and we find that these
systems are not suitable. Therefore, we propose a reference architecture for Software
Development as a Service (SDaaS). The SDaaS reference architecture is the first proposal
which fully supports development of complex software systems in the cloud.
In addition to the reference architecture, we investigate three specific related challenges
and propose novel solutions addressing them. These challenges are:
Modelling & enacting cloud-based executable software processes. Executing
software processes in the cloud can bring several benefits to software develop
ment. In this thesis, we discuss the benefits and considerations of cloud-based
software processes and introduce a modelling language for modelling such processes.
We refer to this language as EXE-SPEM. It extends the Software and Systems
Process Engineering (SPEM2.0) OMG standard to support creating cloudbased
executable software process models. Since EXE-SPEM is a visual modelling
language, we introduce an XML notation to represent EXE-SPEM models
in a machine-readable format and provide mapping rules from EXE-SPEM to
this notation. We demonstrate this approach by modelling an example software
process using EXE-SPEM and mapping it to the XML notation. Software process
models expressed in this XML format can then be enacted in the proposed SDaaS
architecture.
Cost-e cient scheduling of software processes execution in the cloud. Software
process models are enacted in the SDaaS architecture as workflows. We
refer to them sometimes as Software Workflows. Once we have executable software
process models, we need to schedule them for execution. In a setting where
multiple software workflows (and their activities) compete for shared computational
resources (workflow engines), scheduling workflow execution becomes
important. Workflow scheduling is an NP-hard problem which refers to the allocation
of su cient resources (human or computational) to workflow activities.
The schedule impacts the workflow makespan (execution time) and cost as well as
the computational resources utilisation. The target of the scheduling is to reduce
the process execution cost in the cloud without significantly a ecting the process
makespan while satisfying the special requirements of each process activity (e.g.,
executing on a private cloud). We adapt three workflow scheduling algorithms
to fit for SDaaS and propose a fourth one; the Proportional Adaptive Task Schedule.
The algorithms are then evaluated through simulation. The simulation results
show that the our proposed algorithm saves between 19.74% and 45.78% of the
execution cost, provides best resource (VM) utilisation and provides the second
best makespan compared to the other presented algorithms.
Evaluating the SDaaS architecture using a case study from the safety-critical
systems domain. To evaluate the proposed SDaaS reference architecture, we
instantiate a proof-of-concept implementation of the architecture. This imple
mentation is then used to enact safety-critical processes as a case study.
Engineering safety-critical systems is a complex task which involves multiple
stakeholders. It requires shared and scalable computation to systematically involve
geographically distributed teams. In this case study, we use EXE-SPEM to
model a portion of a process (namely; the Preliminary System Safety Assessment
- PSSA) adapted from the ARP4761 [2] aerospace standard. Then, we enact this
process model in the proof-of-concept SDaaS implementation.
By using the SDaaS architecture, we demonstrate the feasibility of our approach
and its applicability to di erent domains and to customised processes. We also
demonstrate the capability of EXE-SPEM to model cloud-based executable processes.
Furthermore, we demonstrate the added value of the process models and
the process execution provenance data recorded by the SDaaS architecture. This
data is used to automate the generation of safety cases argument fragments. Thus,
reducing the development cost and time. Finally, the case study shows that we
can integrate some existing tools and create new ones as activities used in process
models.
The proposed SDaaS reference architecture (combined with its modelling, scheduling
and enactment capabilities) brings the benefits of the cloud to software development. It
can potentially save software production cost and provide an accessible platform that
supports collaborating teams (potentially across di erent locations). The executable
process models support unified interpretation and execution of processes across team(s)
members. In addition, the use of models provide managers with global awareness and
can be utilised for quality assurance and process metrics analysis and improvement.
We see the contributions provided in this thesis as a first step towards an alternative
development method that uses the benefits of cloud and Model-Driven Engineering to
overcome existing challenges and open new opportunities. However, there are several
challenges that are outside the scope of this study which need to be addressed to allow
full support of the SDaaS vision (e.g., supporting interactive workflows). The solutions
provided in this thesis address only part of a bigger vision. There is also a need for
empirical and usability studies to study the impact of the SDaaS architecture on both
the produced products (in terms of quality, cost, time, etc.) and the participating
stakeholders
Advances in Grid Computing
This book approaches the grid computing with a perspective on the latest achievements in the field, providing an insight into the current research trends and advances, and presenting a large range of innovative research papers. The topics covered in this book include resource and data management, grid architectures and development, and grid-enabled applications. New ideas employing heuristic methods from swarm intelligence or genetic algorithm and quantum encryption are considered in order to explain two main aspects of grid computing: resource management and data management. The book addresses also some aspects of grid computing that regard architecture and development, and includes a diverse range of applications for grid computing, including possible human grid computing system, simulation of the fusion reaction, ubiquitous healthcare service provisioning and complex water systems
Bridging a Gap Between Research and Production: Contributions to Scheduling and Simulation
Large scale distributed computing infrastructures (e.g., data centers, grids, or clouds) are used by scientists from various domains to produce outstanding research results, such as the discovery of the Higgs Boson in High Energy Physics. These infrastructures are also studied by Computer Scientists to produce their own set of scientific results. Ideally, a virtuous circle should exist between Domain and Computer Scientists: the former raising challenges that could be addressed by the latter. Unfortunately, in many occasions, a gap exists that prevents such an ideal and fostering collaboration. This habilitation covers research works conducted in the fields of scheduling and simulation that contribute to the filling of this gap. It discusses the necessary conditions to achieve this goal and details concrete initiatives in this endeavor
Resource provisioning and scheduling algorithms for hybrid workflows in edge cloud computing
In recent years, Internet of Things (IoT) technology has been involved in a wide range of application domains to provide real-time monitoring, tracking and analysis services. The worldwide number of IoT-connected devices is projected to increase to 43 billion by 2023, and IoT technologies are expected to engaged in 25% of business sector. Latency-sensitive applications in scope of intelligent video surveillance, smart home, autonomous vehicle, augmented reality, are all emergent research directions in industry and academia. These applications are required connecting large number of sensing devices to attain the desired level of service quality for decision accuracy in a sensitive timely manner. Moreover, continuous data stream imposes processing large amounts of data, which adds a huge overhead on computing and network resources. Thus, latency-sensitive and resource-intensive applications introduce new challenges for current computing models, i.e, batch and stream. In this thesis, we refer to the integrated application model of stream and batch applications as a hybrid work ow model. The main challenge of the hybrid model is achieving the quality of service (QoS) requirements of the two computation systems. This thesis provides a systemic and detailed modeling for hybrid workflows which describes the internal structure of each application type for purposes of resource estimation, model systems tuning, and cost modeling. For optimizing the execution of hybrid workflows, this thesis proposes algorithms, techniques and frameworks to serve resource provisioning and task scheduling on various computing systems including cloud, edge cloud and cooperative edge cloud. Overall, experimental results provided in this thesis demonstrated strong evidences on the responsibility of proposing different understanding and vision on the applications of integrating stream and batch applications, and how edge computing and other emergent technologies like 5G networks and IoT will contribute on more sophisticated and intelligent solutions in many life disciplines for more safe, secure, healthy, smart and sustainable society
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Personal mobile grids with a honeybee inspired resource scheduler
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The overall aim of the thesis has been to introduce Personal Mobile Grids (PMGrids)
as a novel paradigm in grid computing that scales grid infrastructures to mobile devices and extends grid entities to individual personal users. In this thesis, architectural designs as well as simulation models for PM-Grids are developed.
The core of any grid system is its resource scheduler. However, virtually all current conventional grid schedulers do not address the non-clairvoyant scheduling problem, where job information is not available before the end of execution. Therefore, this thesis proposes a honeybee inspired resource scheduling heuristic for PM-Grids (HoPe) incorporating a radical approach to grid resource scheduling to tackle this problem. A detailed design and implementation of HoPe with a decentralised self-management and adaptive policy are initiated.
Among the other main contributions are a comprehensive taxonomy of grid systems as well as a detailed analysis of the honeybee colony and its nectar acquisition process (NAP), from the resource scheduling perspective, which have not been presented in any previous work, to the best of our knowledge.
PM-Grid designs and HoPe implementation were evaluated thoroughly through a strictly controlled empirical evaluation framework with a well-established heuristic in high throughput computing, the opportunistic scheduling heuristic (OSH), as a benchmark algorithm. Comparisons with optimal values and worst bounds are conducted to gain a clear insight into HoPe behaviour, in terms of stability, throughput, turnaround time and speedup, under different running conditions of number of jobs and grid scales.
Experimental results demonstrate the superiority of HoPe performance where it
has successfully maintained optimum stability and throughput in more than 95%
of the experiments, with HoPe achieving three times better than the OSH under
extremely heavy loads. Regarding the turnaround time and speedup, HoPe has
effectively achieved less than 50% of the turnaround time incurred by the OSH, while doubling its speedup in more than 60% of the experiments.
These results indicate the potential of both PM-Grids and HoPe in realising futuristic grid visions. Therefore considering the deployment of PM-Grids in real life scenarios and the utilisation of HoPe in other parallel processing and high throughput computing systems are recommended
Efficient multilevel scheduling in grids and clouds with dynamic provisioning
Tesis de la Universidad Complutense de Madrid, Facultad de Informática, Departamento de Arquitectura de Computadores y Automática, leída el 12-01-2016La consolidación de las grandes infraestructuras para la Computación Distribuida ha resultado en una plataforma de Computación de Alta Productividad que está lista para grandes cargas de trabajo. Los mejores exponentes de este proceso son las federaciones grid actuales. Por otro lado, la Computación Cloud promete ser más flexible, utilizable, disponible y simple que la Computación Grid, cubriendo además muchas más necesidades computacionales que las requeridas para llevar a cabo cálculos distribuidos. En cualquier caso, debido al dinamismo y la heterogeneidad presente en grids y clouds, encontrar la asignación ideal de las tareas computacionales en los recursos disponibles es, por definición un problema NP-completo, y sólo se pueden encontrar soluciones subóptimas para estos entornos. Sin embargo, la caracterización de estos recursos en ambos tipos de infraestructuras es deficitaria. Los sistemas de información disponibles no proporcionan datos fiables sobre el estado de los recursos, lo cual no permite la planificación avanzada que necesitan los diferentes tipos de aplicaciones distribuidas. Durante la última década esta cuestión no ha sido resuelta para la Computación Grid y las infraestructuras cloud establecidas recientemente presentan el mismo problema. En este marco, los planificadores (brokers) sólo pueden mejorar la productividad de las ejecuciones largas, pero no proporcionan ninguna estimación de su duración. La planificación compleja ha sido abordada tradicionalmente por otras herramientas como los gestores de flujos de trabajo, los auto-planificadores o los sistemas de gestión de producción pertenecientes a ciertas comunidades de investigación. Sin embargo, el bajo rendimiento obtenido con estos mecanismos de asignación anticipada (early-binding) es notorio. Además, la diversidad en los proveedores cloud, la falta de soporte de herramientas de planificación y de interfaces de programación estandarizadas para distribuir la carga de trabajo, dificultan la portabilidad masiva de aplicaciones legadas a los entornos cloud...The consolidation of large Distributed Computing infrastructures has resulted in a High-Throughput Computing platform that is ready for high loads, whose best proponents are the current grid federations. On the other hand, Cloud Computing promises to be more flexible, usable, available and simple than Grid Computing, covering also much more computational needs than the ones required to carry out distributed calculations. In any case, because of the dynamism and heterogeneity that are present in grids and clouds, calculating the best match between computational tasks and resources in an effectively characterised infrastructure is, by definition, an NP-complete problem, and only sub-optimal solutions (schedules) can be found for these environments. Nevertheless, the characterisation of the resources of both kinds of infrastructures is far from being achieved. The available information systems do not provide accurate data about the status of the resources that can allow the advanced scheduling required by the different needs of distributed applications. The issue was not solved during the last decade for grids and the cloud infrastructures recently established have the same problem. In this framework, brokers only can improve the throughput of very long calculations, but do not provide estimations of their duration. Complex scheduling was traditionally tackled by other tools such as workflow managers, self-schedulers and the production management systems of certain research communities. Nevertheless, the low performance achieved by these earlybinding methods is noticeable. Moreover, the diversity of cloud providers and mainly, their lack of standardised programming interfaces and brokering tools to distribute the workload, hinder the massive portability of legacy applications to cloud environments...Depto. de Arquitectura de Computadores y AutomáticaFac. de InformáticaTRUEsubmitte
Efficient replication of large volumes of data and maintaining data consistency by using P2P techniques in Desktop Grid
Desktop Grid is increasing in popularity because of relatively very low cost and good performance in institutions. Data-intensive applications require data management in scientific experiments conducted by researchers and scientists in Desktop Grid-based Distributed Computing Infrastructure (DCI). Some of these data-intensive applications deal with large volumes of data. Several solutions for data-intensive applications have been proposed for Desktop Grid (DG) but they are not efficient in handling large volumes of data. Data management in this environment deals with data access and integration, maintaining basic properties of databases, architecture for querying data, etc. Data in data-intensive applications has to be replicated in multiple nodes for improving data availability and reducing response time. Peer-to-Peer (P2P) is a well established technique for handling large volumes of data and is widely used on the internet. Its environment is similar to the environment of DG. The performance of existing P2P-based solution dealing with generic architecture for replicating large volumes of data is not efficient in DG-based DCI. Therefore, there is a need for a generic architecture for replicating large volumes of data efficiently by using P2P in BOINC based Desktop Grid.
Present solutions for data-intensive applications mainly deal with read only data. New type of applications are emerging which deal large volumes of data and Read/Write of data. In emerging scientific experiments, some nodes of DG generate new snapshot of scientific data after regular intervals. This new snapshot of data is generated by updating some of the values of existing data fields. This updated data has to be synchronised in all DG nodes for maintaining data consistency. The performance of data management in DG can be improved by addressing efficient data replication and consistency. Therefore, there is need for algorithms which deal with data Read/Write consistency along with replication for large volumes of data in BOINC based Desktop Grid.
The research is to identify efficient solutions for data replication in handling large volumes of data and maintaining Read/Write data consistency using Peer-to-Peer techniques in BOINC based Desktop Grid. This thesis presents the solutions that have been carried out to complete the research
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