Mohammed H. Haji

A SNAP-Based Community Resource Broker Using a Three-Phase Commit Protocol: A Performance Study

Resource brokering is an essential component in building effective Grid systems. Existing mechanisms employ a traditional approach for resource allocation, which is likely to run into performance problems. This paper presents the development of a broker that is designed within the SNAP (Service Negotiation and Acquisition Protocol) framework and focuses on applications that require resources on demand. The broker uses a three-phase commit protocol as the traditional advance reservation facilities cannot cater to such needs due to the prior time that it requires to schedule the reservation. Experiments have been carried out on a Grid testbed, supported by mathematical modelling and simulation. The experimental results show that the inclusion of the three-phase commit protocol results in a performance enhancement in terms of the time taken from submission of user requirements until a job begins execution. The broker is a viable contender for use in future Grid resource broker implementations.

SLA management in a service oriented architecture

This paper presents a Service Level Agreement (SLA) management architecture for the Grid. SLAs are an essential component in building Grid systems where commitments and assurances are specified, implemented and monitored. Targeting CPU type resources, we show how a SLA manager is able to interface with a broker designed for user applications that require resources on demand. The broker uses a novel three-phase commit protocol which provides the means to secure resources that meet the applications requirements through SLAs. Experiments are carried out on a Grid testbed to show how a SLA for a compute service is specified. Experimental results show that the broker provides performance enhancement in terms of the time taken from submission of application requirements until a job begins execution.

A SNAP-based community resource broker using a three-phase commit protocol

Summary form only given. Resource brokering is an essential component in building effective grid systems. Existing mechanisms employ a traditional approach for resource allocation, which is likely to run into performance problems. We present the development of a broker that is designed within the SNAP (service negotiation and acquisition protocol) framework and focuses on applications that require resources on demand. The broker uses a three-phase commit protocol, as the traditional advance reservation facilities cannot cater for such needs due to the prior time that it requires to schedule the reservation. The experimental results show that the inclusion of the three-phase commit protocol results in a performance enhancement in terms of the time taken from submission of user requirements until a job begins execution. The broker is a viable contender for use in future grid resource broker implementations.

Semantically-Enhanced Model-Experiment-Evaluation Processes (SeMEEPs) within the Atmospheric Chemistry Community

The scientific model development process is often documented in an ad-hoc unstructured manner leading to difficulty in attributing provenance to data products. This can cause issues when the data owner or other interested stakeholder seeks to interpret the data at a later date. In this paper we discuss the design, development and evaluation of a Semantically-enhanced Electronic Lab-Notebook to facilitate the capture of provenance for the model development process, within the atmospheric chemistry community. We then proceed to consider the value of semantically enhanced provenance within the wider community processes, Semantically-enhanced Model-Experiment Evaluation Processes (SeMEEPs), that leverage data generated by experiments and computational models to conduct evaluations.

Deployment and Performance Evaluation of a SNAP-based Resource Broker on the White Rose Grid

Resource brokering is an essential component in building effective Grid systems. The aim of this paper is to evaluate the performance of a SNAP (Service Negotiation and Acquisition Protocol) based resource broker on a large distributed Grid infrastructure, the White Rose Grid. The broker uses a three-phase commit protocol to reserve resources on demand, as the traditional advance reservation facilities cannot cater for such needs due to the prior time that it requires to schedule reservations. Experiments are designed and carried out on the White Rose Grid. The experimental results show that the inclusion of the three-phase commit protocol provides a performance enhancement on a large distributed Grid Infrastructure, in terms of the time taken from submission of user requirements until a job begins execution. The results support those previously obtained through the use of mathematical modelling and simulation. The broker is a viable contender for use in future Grid resource brokering implementations.

Performance Evaluation of a SNAP-Based Grid Resource Broker

Resource brokering is an essential component in building effective Grid systems. The paper discusses the performance evaluation of a broker that is designed within the SNAP (Service Negotiation and Acquisition Protocol) framework and focuses on applications that require resources on demand. The performance evaluation is carried out using a combination of mathematical modelling and simulation. Initial results are presented, indicating that the simulation and modelling are in good agreement.

A User-orientated Electronic Laboratory Notebook for Retrieval and Extraction of Provenance Information for EUROCHAMP-2

This research is concerned with the design and evaluation of an Electronic Laboratory Notebook (ELN) for the simulation of chemical processes. It provides quality provenance information for scientists wishing to compare simulation runs with in vitro experimental data. The research is grounded in the EUROCHAMP-2 community. The community uses a benchmark Master Chemical Mechanism (MCM) in order to undertake their model simulations. The goal is to ensure that, for each atmospheric chamber experiment, a computational model is evaluated/developed using the MCM. This paper builds on earlier research on an ELN for this community. The main contributions are: (1) a re-engineered ELN co-developed by EUROCHAMP-2 chemists and computer scientists where the focus is to enable community scientists to capture and extract useful provenance information, (2) a novel Inline Provenance Node Navigator (IPNav) is provided which enables a modeller to navigate through the trail of the runs as a simulation is created, and (3) the results of an initial user evaluation of the ELN undertaken with two practising modellers.

A user-orientated approach to provenance capture and representation for in silico experiments, explored within the atmospheric chemistry community

We present a novel user-orientated approach to provenance capture and representation for in silico experiments, contrasted against the more systems-orientated approaches that have been typical within the e-Science domain. In our approach, we seek to capture the scientists reasoning in the form of annotations as an experiment evolves, while using the scientists terminology in the representation of process provenance. Our user-orientated approach is applied in a case study within the atmospheric chemistry domain: we consider the design, development and evaluation of an electronic laboratory notebook, a provenance capture and storage tool, for iterative model development.