| 21. |
- Elmroth, Erik, 1964-, et al.
(författare)
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A composable service-oriented architecture for middleware-independent and interoperable grid job management
- 2010
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- We propose a composable, loosely coupled Service-Oriented Architecture for middleware-independent Grid job management. The architecture is designed for use in federated Grid environments and aims to decouple Grid appli- cations from Grid middlewares and other infrastructure components. The notion of an ecosystem of Grid infrastructure components is extended, and Grid job management software design is discussed in this context. Non- intrusive integration models and abstraction of Grid middleware function- ality through hierarchical aggregation of autonomous Grid job management services are emphasized, and service composition techniques facilitating this process are explored. Earlier efforts in Service-Oriented Architecture design are extended upon, and implications of these are discussed throughout the paper. A proof-of-concept implementation of the proposed architecture is presented along with a technical evaluation of the performance of the proto- type, and a details of architecture implementation are discussed along with trade-offs introduced by the service composition techniques used.
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| 22. |
- Elmroth, Erik, 1964-, et al.
(författare)
-
Designing general, composable, and middleware-independent Grid infrastructure tools for multi-tiered job management
- 2007
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Ingår i: Towards Next Generation Grids. - : Springer-Verlag. - 9780387724973 ; , s. 175-184
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Konferensbidrag (refereegranskat)abstract
- We propose a multi-tiered architecture for middleware-independent Grid job management. The architecture consists of a number of services for well-defined tasks in the job management process, offering complete user-level isolation of servicecapabilities, multiple layers of abstraction, control, and fault tolerance. The middleware abstraction layer comprises components for targeted job submission, job control and resource discovery. The brokered job submission layer offers a Grid view on resources, including functionality for resource brokering and submission of jobs to selected resources. The reliable job submission layer includes components for fault tolerant execution of individual jobs and groups of independentjobs, respectively. The architecture is proposed as a composable set of tools rather than a monolithic solution, allowing users to select the individual components of interest. The prototype presented is implemented using the Globus Toolkit 4, integrated with the Globus Toolkit 4 and NorduGrid/ARC middlewares and based on existing and emerging Grid standards. A performance evaluation reveals that the overhead for resource discovery, brokering, middleware-specific format conversions, job monitoring, fault tolerance, and management of individual and groups of jobs is sufficiently small to motivate the use of the framework.
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| 23. |
- Elmroth, Erik, 1964-, et al.
(författare)
-
Designing service-based resource management tools for a healthy grid ecosystem
- 2008
-
Ingår i: Parallel processing and applied mathematics. - Berlin, Heidelberg : Springer-Verlag. ; , s. 259-270
-
Konferensbidrag (refereegranskat)abstract
- We present an approach for development of Grid resource management tools, where we put into practice internationally established high-level views of future Grid architectures. The approach addresses fundamental Grid challenges and strives towards a future vision of the Grid where capabilities are made available as independent and dynamically assembled utilities, enabling run-time changes in the structure, behavior, and location of software. The presentation is made in terms of design heuristics, design patterns, and quality attributes, and is centered around the key concepts of co-existence, composability, adoptability, adaptability, changeability, and interoperability. The practical realization of the approach is illustrated by five case studies (recently developed Grid tools) high-lighting the most distinct aspects of these key concepts for each tool. The approach contributes to a healthy Grid ecosystem that promotes a natural selection of “surviving” components through competition, innovation, evolution, and diversity. In conclusion, this environment facilitates the use and composition of components on a per-component basis.
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| 24. |
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| 25. |
- Elmroth, Erik, 1964-, et al.
(författare)
-
Dynamic and transparent service compositions techniques for service-oriented grid architectures
- 2008
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Ingår i: Integrated research in Grid computing. - : Crete University Press. ; , s. 323-334
-
Bokkapitel (refereegranskat)abstract
- With the introduction of the Service-Oriented Architecture design paradigm, service composition has become a central methodology for developing Grid software. We present an approach to Grid software development consisting of architectural design patterns for service de-composition and service re-composition. The patterns presented can each be used individually, but provide synergistic effects when combined as described in a unified framework. Software design patterns are employed to provide structure in design for service-based software development. Service APIs and immutable data wrappers are used to simplify service client development and isolate service clients from details of underlying service engine architectures. The use of local call structures greatly reduces inter-service communication overhead for co-located services, and service API factories are used to make local calls transparent to service client developers. Light-weight and dynamically replaceable plug-ins provide structure for decision support and integration points. A dynamic configuration scheme provides coordination of service efforts and synchronization of service interactions in a user-centric manner. When using local calls and dynamic configuration for creating networks of cooperating services, the need for generic service monitoring solutions becomes apparent and is addressed by service monitoring interfaces. We present these techniques along with their intended use in the context of software development for service-oriented Grid architectures.
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| 26. |
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| 27. |
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| 28. |
- Espling, Daniel, 1983-, et al.
(författare)
-
Integration and Evaluation of Decentralized Fairshare Prioritization (Aequus)
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Fairshare is commonly one of the factors used by cluster resource management systems to prioritize jobs during scheduling. Despite the grid vision of a transparent and unified infrastructure, fairshare is normally calculated and enforced at the local cluster level rather than at a grid-wide scale. Aequus is a self-contained decentralized system for grid-wide fairshare job prioritization. Using Aequus, detailed global share policies can be combined with local cluster policies to offer a unified grid fairshare prioritization system where local administrations retain control over their clusters. This work shows how Aequus can be integrated with local resource management systems such as SLURM and Maui with minimal intrusion. Early results from production use are presented, and the system is further tested and evaluated for use at a nation-wide scale. Statistical models are created based on historical national grid usage data, and synthetic traces based on these models are used to create a diverse input set used to exemplify system behavior. The system is shown to behave consistently despite great variations in job arrival patterns and partial participation of some of the collaborating installations.
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| 29. |
- Espling, Daniel, et al.
(författare)
-
Integration and evaluation of decentralized fairshare prioritization (Aequus)
- 2014
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Ingår i: Proceedings of the IEEE 28th International Parallel & Distributed Processing Symposium Workshops IPDPSW 2014. - : IEEE Computer Society. - 9781479941162 ; , s. 1198-1207
-
Konferensbidrag (refereegranskat)abstract
- Fairshare is commonly one of the factors used by cluster resource management systems to prioritize jobs during scheduling. Despite the grid vision of a transparent and unified infrastructure, fairshare is normally calculated and enforced at the local cluster level rather than at a grid-wide scale. Aequus is a self-contained decentralized system for grid-wide fairshare job prioritization. Using Aequus, detailed global share policies can be combined with local cluster policies to offer a unified grid fairshare prioritization system where local administrations retain control over their clusters. This work shows how Aequus can be integrated with local resource management systems such as SLURM and Maui with minimal intrusion. Early results from production help assess the maturity of the system, and the system is further tested and evaluated for use at a nation-wide scale using workload modeling techniques. Statistical models are created based on historical national grid usage data, and synthetic traces based on these models are used to create a diverse input set used to exemplify system behavior. The system is shown to behave consistently despite great variations in job arrival patterns and partial participation of some of the collaborating installations.
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| 30. |
- Fernaeus, Sven-Erik, et al.
(författare)
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Cut the coda : early fluency intervals predict diagnoses
- 2008
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Ingår i: Cortex. - : Elsevier BV. - 0010-9452 .- 1973-8102. ; 44:2, s. 161-169
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was threefold: (i) to clarify whether letter and category fluency tap different cognitive abilities; (ii) to make diagnostic comparisons and predictions using temporally resolved fluency data; (iii) to challenge and test the widely made assumption that 1-min sum scores are the fluency test measure of choice in the diagnosis of dementia. Scores from six 10-sec intervals of letter and category fluency tests were obtained from 240 participants including cognitive levels ranging from mild subjective cognitive complaints to Alzheimer's disease. Factor analysis revealed clearly separate factors corresponding to letter and category fluency. Category fluency was markedly impaired in Alzheimer's disease but not in Mild Cognitive Impairment. Only scores from relatively early intervals predicted Alzheimer's disease and Mild Cognitive Impairment. The conclusions are (i) letter and category fluency are different tests, category fluency being the best diagnostic predictor; (ii) it would be possible to administer category fluency tests only for 30 sec, because after this point the necessary differential diagnostic information about the patient's word fluency capacity has already been gathered.
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