Towards an aspect weaving BPEL engine

This position paper proposes the use of dynamic aspects and the visitor design pattern to obtain a highly configurable and extensible BPEL engine. Using these two techniques, the core of this infrastructural software can be customised to meet new requirements and add features such as debugging, execution monitoring, or changing to another Web Service selection policy. Additionally, it can easily be extended to cope with customer-specific BPEL extensions. We propose the use of dynamic aspects not only on the engine itself but also on the workflow in order to tackle the problems of Web Service hot deployment and hot fixes to long running processes. In this way, composing aWeb Service "on-the-fly" means weaving its choreography interface into the workflow

AO-OpenCom: an AO-Middleware architecture supporting flexible dynamic reconfiguration

Middleware has emerged as a key technology in the construction of distributed systems. As a consequence, middleware is increasingly required to be highly modular and configurable, to support separation of concerns between services, and, crucially, to support dynamic reconfiguration: i.e. to be capable of being changed while running. Aspect-oriented middleware is a promising technology for the realisation of distributed reconfiguration in distributed systems. In this paper we propose an aspect-oriented middleware platform called AO-OpenCom that builds AO-based reconfiguration on top of a dynamic component approach to middleware system composition. The goal is to support extremely flexible dynamic reconfiguration that can be applied at all levels of the system and uniformly across the distributed environment. We evaluate our platform by the capability in meeting flexible reconfiguration and the impact of these overheads

AOSD Ontology 1.0 - Public Ontology of Aspect-Orientation

This report presents a Common Foundation for Aspect-Oriented Software Development. A Common Foundation is required to enable effective communication and to enable integration of activities within the Network of Excellence. This Common Foundation is realized by developing an ontology, i.e. the shared meaning of terms and concepts in the domain of AOSD. In the first part of this report, we describe the definitions of an initial set of common AOSD terms. There is general agreement on these definitions. In the second part, we describe the Common Foundation task in detail

JEqualityGen: Generating Equality and Hashing Methods

Manually implementing equals (for object comparisons) and hashCode (for object hashing) methods in large software projects is tedious and error-prone. This is due to many special cases, such as field shadowing, comparison between different types, or cyclic object graphs. Here, we present JEqualityGen, a source code generator that automatically derives implementations of these methods. JEqualityGen proceeds in two states: it first uses source code reflection in MetaAspectJ to generate aspects that contain the method implementations, before it uses weaving on the bytecode level to insert these into the target application. JEqualityGen generates not only correct, but efficient source code that on a typical large-scale Java application exhibits a performance improvement of more than two orders of magnitude in the equality operations generated, compared to an existing system based on runtime reflection. JEqualityGen achieves this by generating runtime profiling code that collects data. This enables it to generate optimised method implementations in a second round

A Closer Look at Fedora's Ingest Performance

4th International Conference on Open RepositoriesThis presentation was part of the session : Fedora User Group PresentationsDate: 2009-05-21 10:30 AM – 12:00 PMIt is of paramount importance for large-scale applications that Fedora can handle huge amounts of data efficiently. While Fedora is generally known to be stable and reliable, there appears to be a lack of data and experience regarding large-scale installations and the performance implications thereof. FIZ Karlsruhe is currently working on several projects with large-scale Fedora repositories holding several million complex objects. We conducted extensive performance and scalability tests with the current Fedora software (mostly version 3.0), focusing on ingest operations. Our goal was to prove that Fedora actually scales well enough for our use cases. Our test runs provided us with data which helped us identifying limits and constraints, and devising some optimization recommendations

A Conceptual Framework for Adapation

This paper presents a white-box conceptual framework for adaptation that promotes a neat separation of the adaptation logic from the application logic through a clear identification of control data and their role in the adaptation logic. The framework provides an original perspective from which we survey archetypal approaches to (self-)adaptation ranging from programming languages and paradigms, to computational models, to engineering solutions

A Conceptual Framework for Adapation

We present a white-box conceptual framework for adaptation. We called it CODA, for COntrol Data Adaptation, since it is based on the notion of control data. CODA promotes a neat separation between application and adaptation logic through a clear identification of the set of data that is relevant for the latter. The framework provides an original perspective from which we survey a representative set of approaches to adaptation ranging from programming languages and paradigms, to computational models and architectural solutions