Migration from COBOL to SOA: Measuring the Impact on Web Services Interfaces Complexity

Enterprises willing to develop Service-Oriented Software (SOS) need to manage their Web Services (WSs) for flexible, agile, quality composition. This paper presents architecture and a specification of a CASE tool for: (1) WSs development and deployment, (2) software composition, and (3) management of WSs, compositions, and the platform on which they run. It specifies the components of the CASE tool architecture that are: (1) a meta-model representing WSs from different perspectives, namely WSs description, legacy systems they wrap, software composed out of them, and their running platform, and (2) a set of management artifacts built on top of the meta-model.

Web service interfaces are considered as one of the critical components of a Service-Oriented Architecture (SOA) and they represent contracts between web service providers and clients (subscribers). These interfaces are frequently modified to meet new requirements. However, these changes in a web service interface typically affect the systems of its subscribers. Thus, it is important for subscribers to estimate the risk of using a specific service and to compare its evolution to other services offering the same features in order to reduce the effort of adapting their applications in the next releases. In addition, the prediction of interface changes may help web service providers to better manage available resources (e.g. programmers’ availability, hard deadlines, etc.) and efficiently schedule required maintenance activities to improve the quality. In this paper, we propose to use machine learning, based on Artificial Neuronal Networks, for the prediction of the evolution of Web services interface design. To this end, we collected training data from quality metrics of previous releases from 6 Web services. The validation of our prediction techniques shows that the predicted metrics value, such as number of operations, on the different releases of the 6 Web services were similar to the expected ones with a very low deviation rate. In addition, most of the quality issues of the studied Web service interfaces were accurately predicted, for the next releases, with an average precision and recall higher than 82 %. The survey conducted with active developers also shows the relevance of prediction technique for both service providers and subscribers.

Analyzing factors of affecting Web Service invocation performance is a hot topic. Among the factors, service interface complexity is a key one investigated by much research work. However, these researches mainly analyze the impact on the performance of primitives, some simple data structures like mesh interface object, or array of them. For the complex data structures, these works lack of a systematic approach to characterize the impact. This paper firstly makes a detailed statistics of service interface complexity based on a large sample space (10K+ WSDL files) on the World Wide Web, and we find about 41.6% services contain complex data structures. The statistic results guide us to conduct many experiments for finding out the correlation of service interface complexity to invocation performance. We discover an interesting feature on commonly used Web Service platforms (Axis/gSOAP/.Net), called Data Structural Form Unaware. As each parameter or return value can be represented as a tree with two kinds of nodes, structure type node and primitive type node, then the feature means that the overhead caused by parameters or return values is independent of the organization of nodes in the trees, but it is only related with the number and the type of nodes. By this feature, we present a simple model to quantify the impact of service interface complexity. Using our model, a Service Interface Performance Vector can be calculated by parsing a WSDL file to estimate the overhead of service interface design. This vector, together with the invocation probability of each operation, generates the Service Interface Performance Score, a comprehensive complexity indicator which can be used to evaluate and rank the service interfaces. At last, a rank report of services on the WWW is shown. Our work can play a guiding role in service interface designing, service interface performance predicting, and ranking.

While legacy systems are becoming incompatible with evolving web service applications, migration of legacy systems towards service-oriented computing is arousing wide concern for the purpose of salvaging the past investments on those systems. In this paper, a black-box strategy is proposed to export customized interactive functionality of legacy systems towards web services using a wrapping methodology suitable to GUI-based legacy systems. Our strategy also proposes a solution to deploy web services that consist of interoperations between user and legacy systems in a service-oriented architecture. Finally, a distributed framework that executes web services and integrates graphical user interfaces of legacy systems is presented.

With the rapid development of Internet, Web Service technology is gradually applied to many areas of life. The security problems occurred in practical applications of Web Service has received more and more attention from the public. Aiming at the security problems existing in the application process of Web Service, a secure real-time internal and external network data exchange method based on Web Service protocol is proposed in this paper, it is agreed that the external network only allows data exchange with the internal network through the Web Service interface, that is, the internal network starts the Web Service service, the external network accesses the service, and then obtains the internal network data or informs the internal network for business processing. Web attack detection is put to the front end to ensure maximum security of Web Service system, which can meet the requirements of more secure and robust web applications while guaranteeing the business security of visitors.

Legacy systems are valuable assets for organisations. They continuously evolve with new emerged technologies in rapidly changing business environment. Web services, together with service-oriented architectures, facilitate legacy system webification and evolution in service-oriented computing environment. Traditional approaches to integrate legacy systems with Web service technology are wrapping a legacy system as a black-box without adequate system understanding. In this paper, we proposed a reengineering approach which applies an improved agglomerative hierarchical clustering algorithm to restructure legacy code and to facilitate legacy code extraction for Web service construction. It supports service identification and service packaging and archives legacy system migration into service-oriented architectures by providing functional legacy code as Web services.

We present a language for specifying web service interfaces. A web service interface puts three kinds of constraints on the users of the service. First, the interface specifies the methods that can be called by a client, together with types of input and output parameters; these are called signature constraints. Second, the interface may specify propositional constraints on method calls and output values that may occur in a web service conversation; these are called consistency constraints. Third, the interface may specify temporal constraints on the ordering of method calls; these are called protocol constraints. The interfaces can be used to check, first, if two or more web services are compatible, and second, if a web service A can be safely substituted for a web service B. The algorithm for compatibility checking verifies that two or more interfaces fulfill each others' constraints. The algorithm for substitutivity checking verifies that service A demands fewer and fulfills more constraints than service B.

It is common that multiple Web services coordinate to achieve a common goal. If two Web services happen to reside on the same runtime system, it is inefficient to communicate via Web services interface. This research proposes our short circuit switch (SCS), which is an intelligent Web services discovery and invocation engine that can be attached to deployed Web services. Our preliminary empirical experience shows that our short circuit switch engine exhibits high performance.

This paper describes the architecture of an airport operation database system (AODBS), which is the most important part of airport information integration system (AIIS) developed by the author. This airport operation database system is a distributed computing system with a multi-layer structure and connected to the rest of the AIIS through web service and message queue interface. The application modules of AODBS are written in C#, web modules written in Java and client modules written in Delphi, the modules communicate with others through web service. In the system, an object-oriented (OO) model of airport operation is developed and object relational mapping (ORM) technique is used to connect the OO model and database. The airport operation database system consists of a database server, three application servers, a web server and about 100 clients. The Architecture of AODBS described in this paper is proved to be reasonable and efficient by actual operation in the airport.

The Web, as we know it, is a collection of human readable pages that are virtually unintelligible to computer programs. For that reason, it has been called the “eyeball” Web. While the Web emerged as a World Wide repository of digitized information, by and large, the very same information is not available for automatic computation. In recent years two parallel efforts emerged that have the potential of overcoming this paradox: the first effort is the Semantic Web which provides the tools for the explicit markup of the content of Web pages; the second effort is the development of Web Services which results in a Web where programs act as independent agents to become the producers and consumers of information and enable automation of business transactions.In this talk I will focus on research that attempts to bridge the gap between the Web as we know it, the Semantic Web and Web services. Under this approach, I propose the vision of Web services as autonomous goal-directed agents which select other agents to interact with, and flexibly negotiate their interaction model, acting at times in client server mode, or at other times in peer to peer mode. The resulting Web services, that I call Autonomous Semantic Web services, utilize ontologies and semantically annotated Web pages to automate the fulfillment of tasks and transactions with other Web agents. In particular, Autonomous Semantic Web services use the Semantic Web to support capability based discovery and interoperation at run time. A first step towards this vision is the development of formal languages and inference mechanisms for representing and reasoning with core concepts of Web services. DAML-S (the Darpa Agent Markup Language for Services) is the first attempt to define such a language. I will give a brief overview of DAML-S and its relations with the Semantic Web and Web services. In addition, I will provide concrete examples of computational models of how DAML-S can be viewed as the first step in bridging the gap between the Semantic Web and current proposed industry standards for Web services. I will provide concrete examples of DAML-S in action, discuss challenges still open in the bridging between the Semantic Web and Web services and provide a roadmap to get us from today’s Web to the Web of autonomous Semantic Web services.KeywordsFormal LanguageCore ConceptDigitize InformationAutomatic ComputationBusiness TransactionThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Like the case of any software, Web Services (WSs) developers could introduce anti-patterns due to the lack of experience and badly-planned changes. During the last decade, search-based approaches have shown their outperformance over other approaches mainly thanks to their global search ability. Unfortunately, these approaches do not consider the uncertainty of class labels. In fact, two experts could be uncertain about the smelliness of a particular WS interface but also about the smell type. Currently, existing works reject uncertain data that correspond to WSs interfaces with doubtful labels. Motivated by this observation and the good performance of the possibilistic K-NN classifier in handling uncertain data, we propose a new evolutionary detection approach, named Web Services Anti-patterns Detection and Identification using Possibilistic Optimized K-NNs (WS-ADIPOK), which can cope with the uncertainty based on the Possibility Theory. The obtained experimental results reveal the merits of our proposal regarding four relevant state-of-the-art approaches.

The explosive growth of the Internet and the Web services technology provides the underpinnings to multimedia web services. However, due to the rich media types in multimedia content and the diversity and heterogeneity in terms of the types of client devices and network connections as well as the special needs and preferences that end users might have, it is very difficult and expensive to provide interface separately for each individual user. Therefore, technologies that can enable universal access the services through an adaptive interface would become critical in the coming pervasive computing era. Further more, customers' requirements and business rules change more often, the need for adaptability in the service level is becoming manifest. In this work, an agent-based adaptive interface is proposed for multimedia Web services. Three intelligent agents: user model agent, content adaptation agent and service agent are introduced and embedded into the interface

Substrate Dependent Galvanotaxis of Directly Reprogrammed Human Neural Precursor Cells

Anchorage-independent myelomonocytic cells acquire adherence within minutes of differentiation stimuli, such as the proteolytically inactive N-terminal fragment of urokinase binding to its cognate glycosylphosphatidylinositol (GPI)-anchored receptor. Here, we report that urokinase-treated differentiating U937 monocyte-like cells exhibit a rapid and transient inhibition of p56/59(hck) and p55(fgr) whereas no changes in the activity of other Src family kinases, such as p53/56(lyn) and p59(fyn) were observed. U937 transfectants expressing a kinase-defective (Lys267 to Met) p56/59(hck) variant exhibit enhanced adhesiveness and a marked F-actin redistribution in thin protruding structures. Conversely, urokinase as well as expression of wild-type or constitutively active (Tyr499 to Phe) p56/59(hck) stimulates the directional migration of uninduced U937 cells. Accordingly, expression of constitutively active or kinase inactive p56/59(hck) selectively prevents urokinase receptor-dependent induction of either adhesion or motility, indicating that a specific activation state of p56/59(hck) is required for each cell response. In conclusion, modulation of the intracellular p56/59(hck) tyrosine kinase activity switches cell motility towards adherence, providing a mutually exclusive mechanism to regulate these properties during monocyte/macrophage differentiation in vivo.

Towards a context-based multi-type policy approach for Web services composition