Reasoning About a Service-oriented Programming Paradigm

This paper is about a new way for programming distributed applications: the service-oriented one. It is a concept paper based upon our experience in developing a theory and a language for programming services. Both the theoretical formalization and the language interpreter showed us the evidence that a new programming paradigm exists. In this paper we illustrate the basic features it is characterized by

CREOLE: a Universal Language for Creating, Requesting, Updating and Deleting Resources

In the context of Service-Oriented Computing, applications can be developed following the REST (Representation State Transfer) architectural style. This style corresponds to a resource-oriented model, where resources are manipulated via CRUD (Create, Request, Update, Delete) interfaces. The diversity of CRUD languages due to the absence of a standard leads to composition problems related to adaptation, integration and coordination of services. To overcome these problems, we propose a pivot architecture built around a universal language to manipulate resources, called CREOLE, a CRUD Language for Resource Edition. In this architecture, scripts written in existing CRUD languages, like SQL, are compiled into Creole and then executed over different CRUD interfaces. After stating the requirements for a universal language for manipulating resources, we formally describe the language and informally motivate its definition with respect to the requirements. We then concretely show how the architecture solves adaptation, integration and coordination problems in the case of photo management in Flickr and Picasa, two well-known service-oriented applications. Finally, we propose a roadmap for future work.Comment: In Proceedings FOCLASA 2010, arXiv:1007.499

Reflective Composition: the declarative composition of roles to unify objects, roles, and aspects [poster session]

As bases for object-orientation, both class-based and prototype-based organization have limitations. We argue that roles have significant benefits as a foundation for organizing objects. We further argue that these benefits can be realised most flexibly using logic meta-programming. Additional benefits from this approach are to reduce redundancy and subsume aspects

Web and Semantic Web Query Languages

A number of techniques have been developed to facilitate powerful data retrieval on the Web and Semantic Web. Three categories of Web query languages can be distinguished, according to the format of the data they can retrieve: XML, RDF and Topic Maps. This article introduces the spectrum of languages falling into these categories and summarises their salient aspects. The languages are introduced using common sample data and query types. Key aspects of the query languages considered are stressed in a conclusion

Statistical performance analysis with dynamic workload using S-NET

Volkmar Wieser, Philip K. F. Hölzenspies, Michael Roßbory, and Raimund Kirner, 'Statistical performance analysis with dynamic workload using S-NET'. Paper presented at the Workshop on Feedback-Directed Compiler Optimization for Multi-Core Architectures. Paris, France 23-25 January 2012In this paper the ADVANCE approach for engineering con- current software systems with well-balanced hardware ef- ficiency is adressed using the stream processing language S-Net. To obtain the cost information in the concurrent system the metrics throughput, latency, and jitter are evalu- ated by analyzing generated synthetical data as well as using an industrial related application in the future. As fall-out an Eclipse plugin for S-Net has been developed to provide sup- port for syntax highlighting, content assistance, hover help, and more, for easier and faster development. The presented results of the current work are on the one hand an indicator for the status quo of the ADVANCE vision and on the other hand used to improve the applied statistical analysis tech- niques within ADVANCE. Like the ADVANCE project, this work is still under development, but further improvements and speedups are expected in the near future

A GPU based real-time software correlation system for the Murchison Widefield Array prototype

Modern graphics processing units (GPUs) are inexpensive commodity hardware that offer Tflop/s theoretical computing capacity. GPUs are well suited to many compute-intensive tasks including digital signal processing. We describe the implementation and performance of a GPU-based digital correlator for radio astronomy. The correlator is implemented using the NVIDIA CUDA development environment. We evaluate three design options on two generations of NVIDIA hardware. The different designs utilize the internal registers, shared memory and multiprocessors in different ways. We find that optimal performance is achieved with the design that minimizes global memory reads on recent generations of hardware. The GPU-based correlator outperforms a single-threaded CPU equivalent by a factor of 60 for a 32 antenna array, and runs on commodity PC hardware. The extra compute capability provided by the GPU maximises the correlation capability of a PC while retaining the fast development time associated with using standard hardware, networking and programming languages. In this way, a GPU-based correlation system represents a middle ground in design space between high performance, custom built hardware and pure CPU-based software correlation. The correlator was deployed at the Murchison Widefield Array 32 antenna prototype system where it ran in real-time for extended periods. We briefly describe the data capture, streaming and correlation system for the prototype array.Comment: 11 pages, to appear in PAS