| 1. |
- Andreozzi, Sergio, et al.
(author)
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GLUE Specification v. 2.0
- 2009
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Reports (other academic/artistic)abstract
- The GLUE specification is an information model for Grid entities described using the natural language and UML Class Diagrams. As a conceptual model, it is designed to be independent from the concrete data models adopted for its implementation. Rendering to concrete data models such XML Schema, LDAP Schema and SQL are provided in a separate document.
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| 2. |
- Andreozzi, Sergio, et al.
(author)
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Towards GLUE 2: Evolution of the Computing Element Information Model
- 2008
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In: Journal of Physics: Conference Series 119 (Proceedings of CHEP07). - : IOP Publishing. - 1742-6596. ; , s. 062009-062009
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Conference paper (peer-reviewed)abstract
- A key advantage of Grid systems is the ability to share heterogeneous resources and services between traditional administrative and organizational domains. This ability enables virtual pools of resources to be created and assigned to groups of users. Resource awareness, the capability of users or user agents to have knowledge about the existence and state of resources, is required in order utilize the resource. This awareness requires a description of the services and resources typically defined via a community-agreed information model. One of the most popular information models, used by a number of Grid infrastructures, is the GLUE Schema, which provides a common language for describing Grid resources. Other approaches exist,however they follow different modeling strategies. The presence of different favors of information models for Grid resources is a barrier for enabling inter-Grid interoperability. In order to solve this problem, the GLUE Working Group in the context of the Open Grid Forum was started. The purpose of the group is to oversee a major redesign of the GLUE Schema which should consider the successful modeling choices and flaws that have emerged from practical experience and modeling choices from other initiatives. In this paper, we present the status of the new model for describing computing resources as the first output from the working group with the aim of dissemination and soliciting feedback from the community.
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| 3. |
- Bayer, Daniel, et al.
(author)
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Dynamic Runtime Environments for Grid Computing
- 2008
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In: CGW'07 Proceedings. - 9788391514191 ; , s. 155-162
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Conference paper (peer-reviewed)abstract
- In a grid computing context the execution of jobs on remote machines of collaborating institutes often requires the provisioning of more than mere CPU time. Besides libraries and utilities distributed with the operating system in question, further software may be required by the jobs and in such cases need to be installed prior to the job's execution. In grid computing this problem is aggravated by decreased personal contacts among collaborators. Currently, Virtual Organisations of existing production grids typically agree on a set of runtime environments that participating sites install manually. The challenge is to automate this process, thus easing the burden of the site's maintainers and allowing grid-wide software updates with immediate eject. This paper presents an RDF based schema for the description of runtime environments and the implementation of a service for their automated and dynamic installation.
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| 4. |
- Eerola, Paula, et al.
(author)
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Roadmap for the ARC Grid Middleware
- 2007
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In: Lecture Notes in Computer Science. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 9783540757542 ; 4699/2007, s. 471-479
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Conference paper (peer-reviewed)abstract
- The Advanced Resource Connector (ARC) or the NorduGrid middleware is an open source software solution enabling production quality computational and data Grids, with special emphasis on scalability, stability, reliability and performance. Since its first release in May 2002, the middleware is deployed and being used in production environments. This paper aims to present the future development directions and plans of the ARC middleware in terms of outlining the software development roadmap.
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| 5. |
- Ekelöf, Tord, et al.
(author)
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LCG and ARC middleware interoperability
- 2006
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Conference paper (peer-reviewed)abstract
- LCG and ARC are two of the major production-ready Grid middleware solutions being used by hundreds of HEP researchers every day. Even though the middlewares are based on same technology, there are substantial architectural and implementational divergencies. An ordinary user faces difficulties trying to cross the boundaries of the two systems: ARC clients so far have not been capable accessing LCG resources and vice versa. After presenting the similarities and differences of the LCG and ARC middlewares, we will focus on the strategies implementing interoperable layers over the two middlewares. The most important areas are the job submission and management and information system components. The basic requirement for the interoperability layer implementation is capability of transparent cross Grid job submission both from ARC and LCG.
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| 6. |
- Ellert, Mattias, et al.
(author)
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Advanced Resource Connector middleware for lightweight computational Grids
- 2007
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In: Future generations computer systems. - : Elsevier BV. - 0167-739X .- 1872-7115. ; 23:2, s. 219-240
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Journal article (peer-reviewed)abstract
- As computational Grids move away from the prototyping state, reliability, performance and ease of use and maintenance become focus areas of their adoption. In this paper, we describe ARC (Advanced Resource Connector) Grid middleware, where these issues have been given special consideration. We present an in-depth view of the existing components of ARC, and discuss some of the new components, functionalities and enhancements currently under development. This paper also describes architectural and technical choices that have been made to ensure scalability, stability and high performance. The core components of ARC have already been thoroughly tested in demanding production environments, where it has been in use since 2002. The main goal of this paper is to provide a first comprehensive description of ARC.
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| 7. |
- Field, Laurence, et al.
(author)
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Grid Information System Interoperability: The Need For A Common Information Model
- 2008
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In: Proceedings of the 2008 Fourth IEEE International Conference on eScience. - 9780769535357 ; , s. 501-507
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Conference paper (peer-reviewed)abstract
- A fundamental building block of any Grid infrastructures is the Grid information service and the information model. The information model describes the entities and relationships between entities within the infrastructure along with their semantics. The realization into a concrete data model defines the syntax by which these concepts can be exchanged. This data model enables consumers of information to efficiently find the information they require and ensures that there is agreement on the meaning with the information producer. The need for a common information model is therefore critical for the seamless interoperation of Grid infrastructures. A number of example interoperation activities are presented which highlight this point and the requirement for a common schema in general. An attempt to achieve interoperability between multiple Grid infrastructures, which was demonstrated at Super Computing 2006, helped motivate work on a common schema within the Open Grid Forum. The result of this effort, GLUE 2.0, which in itself defines the current view of Grid computing, is presented.
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| 8. |
- Konstantinov, A., et al.
(author)
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Data management services of NorduGrid
- 2005
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In: CERN-2005-002. ; 2, s. 765-766
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Conference paper (peer-reviewed)abstract
- In common grid installations, services responsible for storing big data chunks, replication of those data and indexing their availability are usually completely decoupled. And a task of synchronizing data is passed to either user-level tools or separate services (like spiders) which are subject to failure and usually cannot perform properly if one of underlying services fails too. The NorduGrid Smart Storage Element (SSE) was designed to try to overcome those problems by combining the most desirable features into one service. It uses HTTPS/G for secure data transfer, Web Services for control (through same HTTPS/G channel) and can provide information to indexing services used in middlewares based on the Globus Toolkit (TM). At the moment, those are the Replica Catalog and the Replica Location Service. The modular internal design of the SSE and the power of C++ object programming allows to add support for other indexing services in an easy way. There are plans to complement it with a Smart Indexing Service capable of resolving inconsistencies hence creating a robust distributed data storage system.
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| 9. |
- Langgard Nielsen, J., et al.
(author)
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Experiences with Data Indexing services supported by the NorduGrid middleware
- 2005
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In: CERN-2005-002. ; 2, s. 673-675
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Conference paper (peer-reviewed)abstract
- The NorduGrid middleware, ARC, has integrated support for querying and registering to Data Indexing services such as the Globus Replica Catalog and Globus Replica Location Server. This support allows one to use these indexing services for for example brokering during jobsubmission, automatic registration of files and many other things. This integrated support is complemented by a set of command-line tools for registering to and querying these Data Indexing services. In this article we will describe experiences with these indexing services both from a daily work point of view and in production environments such as the Atlas Data- Challenges 1 and 2. We will describe the advantages of such Data Indexing services as well as their shortcomings. Finally we will present a proposal for an extended Smart Indexing Service which should deal with the shortcomings described. Such an indexing service is being designed at the moment.
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| 10. |
- Pajchel, K., et al.
(author)
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Usage statistics and usage patterns on the NorduGrid: Analyzing the logging information collected on one of the largest production Grids of the world
- 2005
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In: CERN-2005-002. ; 2, s. 711-714
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Conference paper (peer-reviewed)abstract
- The Nordic Grid facility (NorduGrid [1]) came into operation during summer 2002 when the Scandinavian ATLAS HEP group started to use the Grid for the ATLAS Data Challenges (DC) and was thus the first Grid ever contributing to an ATLAS production. Since then, the Grid facility has been in continuous 24/7 operation. NorduGrid is being used by a growing set of active users from various scientific areas including physics, chemistry, biology and informatics. It has given major contributions to the ATLAS Data Challenge 1 [2] and the ongoing Data Challenge 2. · The increasing number of resources has made NorduGrid one of the largest production Grids in the world, continuously running on more than 30 sites more than 3000 CPUs. · The resources range from small test clusters at academic institutions to large farms at several supercomputer centers and the NorduGrid software runs on clusters with very different Linux distributions. This presentation gives a short overview of the design and implementation of the NorduGrid middleware, logging and monitoring facilities. It will be followed by a description of a typical job on NorduGrid and the information about its parameters which are monitored online and persistified in the logging service.
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