The verification of Web services becomes a challenge in software verification. This paper presents a framework for verification of Web service interfaces at various abstraction levels. Its foundation is the interface ...
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The verification of Web services becomes a challenge in software verification. This paper presents a framework for verification of Web service interfaces at various abstraction levels. Its foundation is the interface theory for Web services, in which transaction features are incorporated. Within the framework, one may check non mutual invocation, compatibility and refinement of Web services at signature, conversation and protocol levels. At protocol level, we present a model checking approach to verifying the protocol properties in action set computation tree logic (ASCTL). The paper also discusses the integration of our framework into the Web service development
The emerging service-oriented architectures based on Web services is fostering a new generation of intra- and inter-organizational cross-platform Web-based business applications. With the new architectures comes a new...
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The emerging service-oriented architectures based on Web services is fostering a new generation of intra- and inter-organizational cross-platform Web-based business applications. With the new architectures comes a new set of standards (e.g. XML, SOAP, WSDL, UDDI) for enabling self-describing interoperable Web services, as well as for modeling and implementing workflow or process-oriented Web applications. The latter kind of standards include the Web Service Business Process Execution language (BPEL) and the Web Service Choreography Description Language (WS-CDL). While BPEL supports the modeling and implementation of a particular (composite) Web service, WS-CDL can be seen as a behavioral modeling language for the collaboration between multiple parties (Web services) within the same business process. In this paper, we outline how communicating sequential processes (CSP) can be used as a formal basis for checking the behavioral consistency among the participants of a business process with respect to a choreography. The use of a model checking tool for automating the consistency checking is also discussed
RAM (random access memory) Grid is a new grid system aiming at memory resources sharing in wide-area network;it can improve the performance of memory intensive or IO intensive applications when lack of physical memory...
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RAM (random access memory) Grid is a new grid system aiming at memory resources sharing in wide-area network;it can improve the performance of memory intensive or IO intensive applications when lack of physical memory. Reducing or hiding the network overhead can improve the performance of RAM Grid, which lies on the overhead of network communication. In this paper, through the analysis of RAM Grid, a 'push' based prefetching mechanism is proposed for it. The corresponding prefetching algorithm, which comes from the sequential pattern mining method in data mining area, is also raised. The prefetching algorithm is evaluated and proved by trace driven simulation.
Meteorology grid computing aims to provide scientist with seamless, reliable, secure and inexpensive access to meteorological resources. However, the vision of achieving these goals has been encountered with many chal...
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Meteorology grid computing aims to provide scientist with seamless, reliable, secure and inexpensive access to meteorological resources. However, the vision of achieving these goals has been encountered with many challenges such as the degree of easy-to-use and the capability of seamless automation. Fortunately, the emerging semantic Web service and semantic grid technologies bring some significant solutions for the above challenges. Semantic meteorology grid architecture (SMGA) is being developed by us to support automated meteorology grid service discovery, selection, and composition. In this paper, we present a model for semantic annotation and publication of meteorology grid services by combining the expressive power of the present ontology language and the advantages of semantic Web techniques. The presented model is an initial work to support automating the discovery, selection, and workflow composition of semantically described heterogeneous meteorological services, which offers the possibility of facilitating geographically distributed meteorological scientists to resolve complex scientific problems cooperatively
Memory-intensive applications often suffer from the poor performance of disk swapping when memory is inadequate. Remote memory sharing schemes, which provide a remote memory that is faster than the local hard disk, ar...
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ISBN:
(纸本)9781424400546
Memory-intensive applications often suffer from the poor performance of disk swapping when memory is inadequate. Remote memory sharing schemes, which provide a remote memory that is faster than the local hard disk, are able to improve the performance of such applications. Due to the limitation of being applicable within single clusters only, however, most of the previous remote memory mechanisms, such as the network memory scheme, fail to be extendable into a large scale, distributed, heterogeneous, and dynamic environment. In this work, we propose a service-oriented grid memory sharing scheme, distributed paging RAM grid (DPRG). We study the properties and criteria of large scale memory sharing, and then design major operations and optimizations to fit the usage of grid systems. We collect trace from our grid environment, and evaluate DPRG through comprehensive trace-driven simulations. Results show that DPRG significantly outperforms existing remote memory sharing schemes and supports grid computing applications effectively
Many scientific computing applications demand a great amount of memory, which are usually run on supercomputers with large physical memory. The applications whose complete time is affected by memory capacity, is usual...
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Many scientific computing applications demand a great amount of memory, which are usually run on supercomputers with large physical memory. The applications whose complete time is affected by memory capacity, is usually called memory-intensive applications. Many disk 10 operations will be caused by memory-intensive applications due to insufficient physical memory of computing environment, which depress the system performance dramatically. Traditional network memory or memory server schemes try to share free memory of idle nodes in the cluster, while it is often influenced by heavy cluster loading or interior network congestion. Combining the network memory with current service computing and grid computing technology, a memory service based memory sharing grid system named RAM Grid, is proposed. RAM grid improve traditional network memory scheme, and extend the application area of grid computing. As one of the major computing resources, memory can be shared on the Internet through RAM grid, such as computing power and disk storage being shared through computational grid and data grid. The system criteria and properties are analyzed. One of the system schemes is also proposed in detail. Through the real trace based simulation, the performance of RAM Grid is evaluated and proved better than traditional network memory or disk IO obviously.
The conjugate residual (CR) algorithm is a Krylov subspace algorithm that can be used to obtain fast solutions for symmetric linear systems with very large and very sparse coefficient matrices. By changing the computa...
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The conjugate residual (CR) algorithm is a Krylov subspace algorithm that can be used to obtain fast solutions for symmetric linear systems with very large and very sparse coefficient matrices. By changing the computation sequence in the CR algorithm, this paper proposes an improved Conjugate Residual (ICR) algorithm. The numerical stability of ICR algorithm is same as CR algorithm, but the synchronization overhead that represents the bottleneck of the parallel performance is effectively reduced by a factor of two. And all inner products of a single iteration step are independent and communication time required for inner product can be over lapped efficiently with computation time of vector updates. From the theoretical and experimental analysis it is found that ICR algorithm is faster than CR algorithm as the number of processors in creases. The experiments performed on a 64-processor cluster indicate that ICR is approximately 30% faster than CR.
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