International Conference on e-Science 

About: International Conference on e-Science is an academic conference. The conference publishes majorly in the area(s): Grid computing & Grid. Over the lifetime, 1134 publications have been published by the conference receiving 12891 citations.

Cost-based scheduling of scientific workflow applications on utility grids

Abstract: Over the last few years, grid technologies have progressed towards a service-oriented paradigm that enables a new way of service provisioning based on utility computing models. Users consume these services based on their QoS (quality of service) requirements. In such "pay-per-use" grids, workflow execution cost must be considered during scheduling based on users' QoS constraints. In this paper, we propose a cost-based workflow scheduling algorithm that minimizes execution cost while meeting the deadline for delivering results. It can also adapt to the delays of service executions by rescheduling unexecuted tasks. We also attempt to optimally solve the task scheduling problem in branches with several sequential tasks by modeling the branch as a Markov decision process and using the value iteration method

WorkflowSim: A toolkit for simulating scientific workflows in distributed environments

Abstract: Simulation is one of the most popular evaluation methods in scientific workflow studies. However, existing workflow simulators fail to provide a framework that takes into consideration heterogeneous system overheads and failures. They also lack the support for widely used workflow optimization techniques such as task clustering. In this paper, we introduce WorkflowSim, which extends the existing CloudSim simulator by providing a higher layer of workflow management. We also indicate that to ignore system overheads and failures in simulating scientific workflows could cause significant inaccuracies in the predicted workflow runtime. To further validate its value in promoting other research work, we introduce two promising research areas for which WorkflowSim provides a unique and effective evaluation platform.

Scientific workflow applications on Amazon EC2

Abstract: The proliferation of commercial cloud computing providers has generated significant interest in the scientific computing community. Much recent research has attempted to determine the benefits and drawbacks of cloud computing for scientific applications. Although clouds have many attractive features, such as virtualization, on-demand provisioning, and “pay as you go” usage-based pricing, it is not clear whether they are able to deliver the performance required for scientific applications at a reasonable price. In this paper we examine the performance and cost of clouds from the perspective of scientific workflow applications. We use three characteristic workflows to compare the performance of a commercial cloud with that of a typical HPC system, and we analyze the various costs associated with running those workflows in the cloud. We find that the performance of clouds is not unreasonable given the hardware resources provided, and that performance comparable to HPC systems can be achieved given similar resources. We also find that the cost of running workflows on a commercial cloud can be reduced by storing data in the cloud rather than transferring it from outside.

High-performance task distribution for volunteer computing

Abstract: Volunteer computing projects use a task server to manage work. Clients periodically communicate with the server to report completed tasks and get new tasks. The rate at which the server can dispatch tasks may limit the computing power available to the project. This paper discusses the design of the task server in BOINC, a middleware system for volunteer computing. We present measurements of the CPU time and disk I/O used by a BOINC server, and show that a server consisting of a single inexpensive computer can distribute on the order of 8.8 million tasks per day. With two additional computers this increases to 23.6 million tasks per day

Mechanisms for Data Quality and Validation in Citizen Science

Abstract: Data quality is a primary concern for researchers employing a public participation in scientific research (PPSR) or ``citizen science'' approach This mode of scientific collaboration relies on contributions from a large, often unknown population of volunteers with variable expertise In a survey of PPSR projects, we found that most projects employ multiple mechanisms to ensure data quality and appropriate levels of validation We created a framework of 18 mechanisms commonly employed by PPSR projects for ensuring data quality, based on direct experience of the authors and a review of the survey data, noting two categories of sources of error (protocols, participants) and three potential intervention points (before, during and after participation), which can be used to guide project design