Towards a re-engineering method for web services architectures

Recent developments in Web technologies – in particular through the Web services framework – have greatly enhanced the flexible and interoperable implementation of service-oriented software architectures. Many older Web-based and other distributed software systems will be re-engineered to a Web services-oriented platform. Using an advanced e-learning system as our case study, we investigate central aspects of a re-engineering approach for the Web services platform. Since our aim is to provide components of the legacy system also as services in the new platform, re-engineering to suit the new development paradigm is as important as re-engineering to suit the new architectural requirements

ImageJ2: ImageJ for the next generation of scientific image data

ImageJ is an image analysis program extensively used in the biological sciences and beyond. Due to its ease of use, recordable macro language, and extensible plug-in architecture, ImageJ enjoys contributions from non-programmers, amateur programmers, and professional developers alike. Enabling such a diversity of contributors has resulted in a large community that spans the biological and physical sciences. However, a rapidly growing user base, diverging plugin suites, and technical limitations have revealed a clear need for a concerted software engineering effort to support emerging imaging paradigms, to ensure the software's ability to handle the requirements of modern science. Due to these new and emerging challenges in scientific imaging, ImageJ is at a critical development crossroads. We present ImageJ2, a total redesign of ImageJ offering a host of new functionality. It separates concerns, fully decoupling the data model from the user interface. It emphasizes integration with external applications to maximize interoperability. Its robust new plugin framework allows everything from image formats, to scripting languages, to visualization to be extended by the community. The redesigned data model supports arbitrarily large, N-dimensional datasets, which are increasingly common in modern image acquisition. Despite the scope of these changes, backwards compatibility is maintained such that this new functionality can be seamlessly integrated with the classic ImageJ interface, allowing users and developers to migrate to these new methods at their own pace. ImageJ2 provides a framework engineered for flexibility, intended to support these requirements as well as accommodate future needs

A Case Study on Software Evolution towards Service-Oriented Architecture.

The evolution of any software product over its lifetime is unavoidable, caused both by bugs to be fixed and by new requirements appearing in the later stages of the product’s lifecycle. Traditional development and architecture paradigms have proven to be not suited for these continual changes, resulting in large maintenance costs. This has caused the rise of approaches such as Service Oriented Architectures (SOA), based on loosely coupled, interoperable services, aiming to address these issues. This paper describes a case study of the evolution of an existing legacy system towards a more maintainable SOA. The proposed process includes the recovery of the legacy system architecture, as a first step to define the specific evolution plan to be executed and validated. The case study has been applied to a medical imaging system, evolving it into a service model

Two ways to Grid: the contribution of Open Grid Services Architecture (OGSA) mechanisms to service-centric and resource-centric lifecycles

Service Oriented Architectures (SOAs) support service lifecycle tasks, including Development, Deployment, Discovery and Use. We observe that there are two disparate ways to use Grid SOAs such as the Open Grid Services Architecture (OGSA) as exemplified in the Globus Toolkit (GT3/4). One is a traditional enterprise SOA use where end-user services are developed, deployed and resourced behind firewalls, for use by external consumers: a service-centric (or ‘first-order’) approach. The other supports end-user development, deployment, and resourcing of applications across organizations via the use of execution and resource management services: A Resource-centric (or ‘second-order’) approach. We analyze and compare the two approaches using a combination of empirical experiments and an architectural evaluation methodology (scenario, mechanism, and quality attributes) to reveal common and distinct strengths and weaknesses. The impact of potential improvements (which are likely to be manifested by GT4) is estimated, and opportunities for alternative architectures and technologies explored. We conclude by investigating if the two approaches can be converged or combined, and if they are compatible on shared resources

Käytettävyyden ja kehityksen modernisointi mikropalveluilla

Vanhat ohjelmistojärjestelmät, joilla tarkoitetaan vanhoja ja vanhentuneita ohjelmistoja joita on tehty vanhentuneilla työskentelytavoilla, ovat todellisuus jonka kanssa suurin osa ohjelmistokehitysyrityksistä joutuvat kamppailemaan. Vanhat työskentelytavat ja teknologiat aiheuttavat usein ohjelmiston kehityksen ja julkaisun hidastumista, sillä niiden jatkuvassa käytössä voi piillä yhteensopivuus, turvallisuus, skaalautuvuus sekä ekonomisia ongelmia, muiden ongelmien muassa. Ohjelmistojärjestelmien modernisointi, uudelleensuunnittelu ja refaktorointi voivat lievittää vanhoista järjestelmistä nousevia ongelmia, oli se sitten työskentelytapojen muutoksella, teknologioiden päivityksellä tai ohjelmistoalustojen vaihdolla. On olemassa monia teknologioita ja metodeja jotka voivat helpottaa ohjelmistojärjestelmien modernisointia, mukaanlukien siirto käyttämään erilaista arkkitehtuuria, uusien teknologioiden käyttöönotto ja ohjelmistokehityksen tapojen vaihto. Näillä teknologioilla ja metodeilla, ja modernisaatiolla yleensäkkin, on omat riskinsä ja haasteensa, jotka tulee ottaa huomioon onnistuneen modernisaation aikaansaamiseksi; Nämä strategiset huomiot ovat avaintekijöitä modernisaatiossa. Tämä opinnäytetyö tutkii ohjelmistojen modernisaatiota yleisellä tasolla kirjallisuusarvostelun kautta, ja käyttää tietyn yrityksen tapaustutkimuksen dataa, joka on kerätty kyselyjen ja yhtiön lokien kautta, katsoen mitä teknologioita, konsepteja ja strategioita tarvitaan onnistuneeseen modernisaatioon, ja mitä vaikutuksia modernisaatiolla on modernisoitavaan ohjelmistojärjestelmään loppukäyttäjien sekä ohjelmistokehittäjien näkökulmasta. Tämän tutkimuksen lopputulos paljastaa miksi modernisaatio on monimutkainen aihe jossa on monia haasteita, mutta joka samaan aikaan tarjoaa monia hyötyjä modernisoitavalle ohjelmistojärjestelmälle. Näitä tuloksia on parasta käyttää ohjeina siihen, mihin ongelmiin kannattaa keskittyä modernisoinnin aikana, pitäen mielessä tapaustutkimuksen rajoitetun soveltamisalan.Legacy software systems, which refers to old and likely outdated software applications and practices, are a reality that most software development companies have to contend with. Old practices and technologies are often at fault for slowing down development and deployment of software, as they can have compatibility, security, scalability and economic issues with their continued use, among other issues. Software modernization, reengineering and refactoring can alleviate the issues stemming from legacy systems, whether it be in the form of altering practices, updating technologies or changing platforms. There are many technologies and methods that can facilitate the modernization of a software system, including a move to using different architectures, specific newer technologies and changing the methods of working and developing the software system. These technologies and methods, and modernization in general, come with their own risks and challenges that must be considered for a successful modernization to take place; These strategic considerations are a key factor in modernization. This thesis will explore software modernization in general through literature reviews and as a case study for a specific company using data from surveys and the case company’s logs, with a look into the technologies, concepts and strategies required for a successful modernization, and what kinds of effects modernization can have on the software system being modernized, both from a user perspective as well as from a developer perspective. The end-result of this exploration reveals that modernization is a complex subject with many challenges, but that also offers benefits to the software system being modernized. These results are best used as a guideline on what issues should be concentrated on during modernization, with a mindful consideration for the limited scope of the case study represented within