Management of SPMD based parallel processing on clusters of workstations

Current attempts to manage parallel applications on Clusters of Workstations (COWs) have either generally followed the parallel execution environment approach or been extensions to existing network operating systems, both of which do not provide complete or satisfactory solutions. The efficient and transparent management of parallelism within the COW environment requires enhanced methods of process instantiation, mapping of parallel process to workstations, maintenance of process relationships, process communication facilities, and process coordination mechanisms. The aim of this research is to synthesise, design, develop and experimentally study a system capable of efficiently and transparently managing SPMD parallelism on a COW. This system should both improve the performance of SPMD based parallel programs and relieve the programmer from the involvement into parallelism management in order to allow them to concentrate on application programming. It is also the aim of this research to show that such a system, to achieve these objectives, is best achieved by adding new special services and exploiting the existing services of a client/server and microkernel based distributed operating system. To achieve these goals the research methods of the experimental computer science should be employed. In order to specify the scope of this project, this work investigated the issues related to parallel processing on COWs and surveyed a number of relevant systems including PVM, NOW and MOSIX. It was shown that although the MOSIX system provide a number of good services related to parallelism management, none of the system forms a complete solution. The problems identified with these systems include: instantiation services that are not suited to parallel processing; duplication of services between the parallelism management environment and the operating system; and poor levels of transparency. A high performance and transparent system capable of managing the execution of SPMD parallel applications was synthesised and the specific services of process instantiation, process mapping and process interaction detailed. The process instantiation service designed here provides the capability to instantiate parallel processes using either creation or duplication methods and also supports multiple and group based instantiation which is specifically design for SPMD parallel processing. The process mapping service provides the combination of process allocation and dynamic load balancing to ensure the load of a COW remains balanced not only at the time a parallel program is initialised but also during the execution of the program. The process interaction service guarantees to maintain transparently process relationships, communications and coordination services between parallel processes regardless of their location within the COW. The combination of these services provides an original architecture and organisation of a system that is capable of fully managing the execution of SPMD parallel applications on a COW. A logical design of a parallelism management system was developed derived from the synthesised system and was shown that it should ideally be based on a distributed operating system employing the client server model. The client/server based distributed operating system provides the level of transparency, modularity and flexibility necessary for a complete parallelism management system. The services identified in the synthesised system have been mapped to a set of server processes including: Process Instantiation Server providing advanced multiple and group based process creation and duplication; Process Mapping Server combining load collection, process allocation and dynamic load balancing services; and Process Interaction Server providing transparent interprocess communication and coordination. A Process Migration Server was also identified as vital to support both the instantiation and mapping servers. The RHODOS client/server and microkernel based distributed operating system was selected to carry out research into the detailed design and to be used for the implementation this parallelism management system. RHODOS was enhanced to provide the required servers and resulted in the development of the REX Manager, Global Scheduler and Process Migration Manager to provide the services of process instantiation, mapping and migration, respectively. The process interaction services were already provided within RHODOS and only required some extensions to the existing Process Manager and IPC Managers. Through a variety of experiments it was shown that when this system was used to support the execution of SPMD parallel applications the overall execution times were improved, especially when multiple and group based instantiation services are employed. The RHODOS PMS was also shown to greatly reduce the programming burden experienced by users when writing SPMD parallel applications by providing a small set of powerful primitives specially designed to support parallel processing. The system was also shown to be applicable and has been used in a variety of other research areas such as Distributed Shared Memory, Parallelising Compilers and assisting the port of PVM to the RHODOS system. The RHODOS Parallelism Management System (PMS) provides a unique and creative solution to the problem of transparently and efficiently controlling the execution of SPMD parallel applications on COWs. Combining advanced services such as multiple and group based process creation and duplication; combined process allocation and dynamic load balancing; and complete COW wide transparency produces a totally new system that addresses many of the problems not addressed in other systems.

Automatic parallelisation and execution of applications on clusters

Parallel execution is a very efficient means of processing vast amounts of data in a small amount of time. Creating parallel applications has never been easy, and requires much knowledge of the task and the execution environment used to execute parallel processes. The process of creating parallel applications can be made easier through using a compiler that automatically parallelises a supplied application. Executing the parallel application is also simplified when a well designed execution environment is used. Such an execution environment provides very powerful operations to the programmer transparently. Combining both a parallelising compiler and execution environment and providing a fully automated parallelisation and execution tool is the aim of this research. The advantage of using such a fully automated tool is that the user does not need to provide any additional input to gain the benefits of parallel execution. This report shows the tool and how it transparently supports the programmer creating parallel applications and supports their execution.

Preemptive job scheduling policy for distributively-owned workstation clusters

Cluster computing has come to prominence as a cost-effective parallel processing tool for solving many complex computational problems. In this paper, we propose a new timesharing opportunistic scheduling policy to support remote batch job executions over networked clusters to be used in conjunction with the Condor Up-Down scheduling algorithm. We show that timesharing approaches can be used in an opportunistic setting to improve both mean job slowdowns and mean response times with little or no throughput reduction. We also show that the proposed algorithm achieves significant improvement in job response time and slowdown as compared to exiting approaches and some recently proposed new approaches.

What does it meme? The exegesis as valorisation and validation of creative arts research

This paper will draw on Richard Dawkin's idea of the 'meme' to discuss how the creative arts exegesis can operate as valorisation and validation of creative arts research. According to Dawkins, the rate and fecundity of replication permits an artefact to achieve recognition and stability as a meme within a culture. The value and application of traditional forms of research is underpinned by a secondary order of production, publication, that establishes visibility of the work and articulates its empirical processes and findings as sources of social benefit and cultural enhancement.

In the arts, conventional modes of valorisation such as the gallery system, reviews and criticism focus on the artistic product and hence, lack sustained engagement with the creative processes as models of research. Such engagement is necessary to articulate and validate studio practices as modes of enquiry.

A crucial question to initiate this engagement is: 'What did the studio process reveal that could not have been revealed by any other mode of enquiry?'

Re-versioning of the studio process and its significant moments through the exegesis locates the work within the broader field of practice and theory. It is also part of the replication process that establishes the creative arts as a stable research discipline, able to withstand peer and wider assessment. The exegesis is a primary means of realising creative arts research as 'meme'.

A comparative study at the logical level of centralised and distributed recovery in clusters

Cluster systems are becoming more prevalent in today’s computer society and users are beginning to request that these systems be reliable. Currently, most clusters have been designed to provide high performance at the cost of providing little to no reliability. To combat this, this report looks at how a recovery facility, based on either a centralised or distributed approach could be implemented into a cluster that is supported by a check pointing facility. This recovery facility can then recover failed user processes by using checkpoints of the processes that have been taken during failure free execution.

Execution environments and benchmarks for the study of applications' scheduling on clusters

In this paper, we have demonstrated how the existing programming environments, tools and middleware could be used for the study of execution performance of parallel and sequential applications on a non-dedicated cluster. A set of parallel and sequential benchmark applications selected for and used in the experiments were characterized, and experiment requirements shown. 

Contesting binarisms in Harry Potter : creative rejigging, or gender tokenism?

This paper arises out of curiosity inspired by four Japanese women students' consumption in English of the entire Harry Potter series (five increasingly lengthy books) in 2003, and it asks whether the six novels are regressive or creative on gender grounds. In a series which pivots around binaries and rarely complicates them, does gender come in for the same treatment? In updating the schoolboy/schoolgirl and action/magic genres and locating them in a co-ed setting, does the author of Harry Potter write as a woman or does she cling to regressive gender scripts?

Enhancing the creative process for learning in primary technology education

When undertaking design and technology activities, children are provided with opportunities to create solutions to problems in new and innovative ways. The mental processes involved in the generation of new ideas may be enhanced when children’s attention is not focussed and is allowed to wander in a relaxed and uncompetitive environment. Research indicates that the two mental states, generative and non-generative, cannot exist simultaneously. This paper reports on a research project which investigated the impact on children’s thinking when a period of non-focussed thinking became part of the technology process. The results support the previous proposition that a child’s non-generative/analytical mental state needs to give way to a generative state so that a child can be more fully creative. Moreover, from this study that documented children’s ideas during their involvement in a design and technology activity, teachers are urged to provide an incubation period as part of the technological process in the classroom, so that children’s creativity can be fostered.

Building autonomic clusters : a response to IBM’s autonomic computing challenge

IBM has announced Autonomic Computing as one of its Grand Challenges. A list of characteristics was generated to describe an autonomic computing system. Many researchers and research group have responded positively to the challenge by initiating research around one or two of the characteristics identified by IBM as the requirements for Autonomic Computing. We have addressed the IBMrsquos request to contribute to the challenge by building an autonomic operating system that possesses nearly all IBM characteristics. This paper contains our response to the IBMrsquos Autonomic Computing Challenge.

Toward an operating system that supports parallel processing on nondedicated clusters

Present operating systems are not built to support parallel computing on clusters - they do not provide services to manage parallelism, i.e., to manage parallel processes and cluster resources. They do not provide support for both programming paradigms, Message Passing (MP) or Distributed Shared Memory (DSM). Due to poor operating systems, users must deal with computers of a cluster rather than to see this cluster as a single powerful computer. There is a need for cluster operating systems. We claim that it is possible to develop a cluster operating system that is able to efficiently manage parallelism, support MP and DSM and offer transparency. To substantiate this claim the first version of a cluster operating system managing parallelism and offering transparency, called GENESIS, has been developed.

A brief review of PhDs in creative and performing arts in Australia

This paper reports on an aspect of a pilot project conducted in 2003 by the authors comprising a bibliographic analysis of all (approximately 51,000) Australian PhDs. The pilot work is both a data and methodological basis for a larger project that investigates the nature and development of PhDs in Australia as they evolved in the context of national economic, social and educational changes. This paper reviews the evidence from the bibliographic data held in library catalogues of PhDs in each Australian university. After considering the definitional properties and their operationalisation, the paper provides an overview of the first instances, locations and frequencies of PhDs in the creative and performing arts in Australia, fields which are relatively new to doctoral study and which pose challenges in terms of doctoral pedagogy and scholarship. This is contextualised in terms of the development of the contemporary university sector during the 1990s, including the growth in the creative and performing arts therein.

Toward highly available, self-healing, adaptable, grid-like and user friendly nondedicated clusters

The human body was used to illustrate an Autonomic Computing system that possesses self-knowledge, self-configuration, self-optimization, self-healing, and self-protection, knowledge of its environment and user friendliness properties. Autonomic Computing was identified by IBM as one of the Grand Challenges. Many researchers and research groups have responded positively to the challenge by initiating research around one or two of the characteristics
identified by IBM as the requirements for Autonomic Computing. One of the areas that could benefit from the comprehensive approach created by the Autonomic Computing vision is parallel processing on nondedicated clusters. This paper shows a general design of services and initial implementation of a system that moves parallel processing on clusters to the computing mainstream using the Autonomic Computing vision.