Piyush Maheshwari

Policy-driven middleware for self-adaptation of web services compositions

We present our policy-based middleware, called Manageable and Adaptive Service Compositions (MASC), for dynamic self-adaptation of Web services compositions to various changes. MASC integrates and extends our earlier middleware called the Web Services Message Bus (wsBus). In particular, we discuss MASC support for customization of Web services compositions to address business exceptions and wsBus support for correction (fault management) of Web services compositions to improve reliability. We have evaluated the former support on a stock trading case study and the latter support on a supply chain management case study. Our solutions are complementary to the existing approaches and provide: coordination of fault management between SOAP messaging and business process orchestration, greater diversity of monitoring and control constructs, specification of both technical and business aspects used for adaptation decisions, higher level of abstraction easier for use by non-technical people, and externalization of monitoring and adaptation actions from definitions of business processes.

A broker-based approach for improving Web services reliability

As Web services start to be deployed for mission-critical applications and for e-business scenarios, higher quality of service (QoS) and continuous service delivery become a critical issue to ensure high availability and reliability in spite of the failure or unavailability of the participating services or networks. These challenges call for vast improvements in the Web services containers and the mediation infrastructure. To address these requirements, we propose Web services message bus (wsBus), a lightweight service-oriented middleware for reliable and fault tolerant Web services interactions. This paper first discusses wsBus architecture and features and then it reports some experimental results to illustrate the effectiveness of wsBus in adding reliable and uninterrupted services to a supply chain management system.

wsBus: QoS-aware middleware for reliable Web services interactions

Service-oriented architecture (SOA) using Web services is considered as the state-of-the-art for distributed systems integration. As Web services start to be deployed across enterprise boundaries and for collaborative e-business scenarios, higher quality of service (QoS) and reliable inter-application messaging becomes a critical issue to ensure guaranteed and ordered delivery even in the case of system or network failures or temporary service outage. To address these requirements, we propose wsBus, a lightweight service-oriented middleware for dependable Web services interactions using broker pattern. We discuss the system architecture and features then report our experiences in building wsBus as well as some initial performance results.

Enhancing Web services with message-oriented middleware

This paper outlines the design and implementation of WSMQ, which is a message-oriented middleware specifically designed to enhance the reliability of Web services. Highlights of this application feature fault tolerance of Web services communication, Quality of Services including authentication and prioritization, security enhancement and performance improvements in Web services over the existing architecture. The implementation of these features aims to address the existing issues surrounding Web services, and further its advancement towards a new standard for distributed application development.

WS-Policy4MASC - A WS-Policy Extension Used in the MASC Middleware

WS-Policy4MASC is a new XML language that we developed for specification of monitoring and control (particularly, adaptation) policies in the Manageable and Adaptable Services Compositions (MASC) middleware. It extends the Web Services Policy Framework (WS-Policy) by defining new types of policy assertions. Goal policy assertions specify requirements and guarantees to be met in desired normal operation. Action policy assertions specify actions to be taken if certain conditions are met or not met. Utility policy assertions specify monetary values assigned to particular situations. Meta-policy assertions are used to specify which action policy assertions are alternatives and which business value-driven conflict resolution strategy should be used. WS- Policy4MASC also enables detailed specification of additional information necessary for run-time policy-driven management. We evaluated feasibility of the WS- Policy4MASC solutions by implementing a policy repository and other modules in MASC. We examined their usefulness on a set of realistic scenarios.

Towards a policy-driven framework for adaptive Web services composition

The variation of contexts in which a Web service could be used and the resulting variation in functional and quality of service (QoS) requirements motivates further research to extend Web services platforms to cater for differentiated service offerings and dynamic adaptability. Adaptability is an important requirement in the context of Web services to cater for the need of diverse set of client applications requesting customized view of consumed Web services to fit their own contexts and preferences. This paper presents an ongoing project to devise a novel service composition framework, named AdaptiveBPEL that leverages aspect-oriented software development (AOSD) techniques to open up the service composition for dynamic change in order to provide a greater degree of configurability and dynamic adaptability of Web services. This framework can: 1) easily adapt to changes in business rules, and collaboration policies governing service interactions; 2) provide different levels of functional and QoS offerings. The adaptation process is policy-driven to declaratively define the adaptive service behavior through dynamic injection of functional and non-functional extensions into a core service composition to allow on-demand and per-instance service adaptability.

Benchmarking message-oriented middleware: TIB/RV versus SonicMQ

Message‐oriented middleware (MOM) has become a vital part of the complex application integration projects. MOM is used to pass data and workflow in the form of messages between different enterprise applications. The performance of integrated applications greatly depends on how effectively the MOM performs. This paper presents a benchmark comparison between two industry well‐known MOMs—TIBCO Rendezvous (TIB/RV) and SonicMQ. Although the two MOMs are very similar in certain respects, their native implementation and architecture are very different. We provide an unbiased benchmark reference to the middleware selection process. The primary objective of our work is to evaluate and compare the MOMs by testing their effectiveness in the delivery of messages in publish/subscribe and point‐to‐point message domains, their program stability and the system resource utilization. Copyright

Notice of Violation of IEEE Publication Principles Dynamic Binding Framework for Adaptive Web Services

Dynamic selection and composition of autonomous and loosely-coupled Web services is increasingly used to automate business processes. The typical long-running characteristic of business processes imposes new management challenges such as dynamic adaptation of running process instances. To address this, we developed a policy-based framework, named manageable and adaptable service compositions (MASC) , to declaratively specify policies that govern: (1) discovery and selection of services to be used, (2) monitoring to detect the need for adaptation, (3) reconfiguration and adaptation of the process to handle special cases (e.g., context-dependant behavior) and recover from typical faults in service-based processes. The identified constructs are executed by a lightweight service-oriented management middleware named MASC middleware. We implemented a MASC proof-of-concept prototype and evaluated it on stock trading case study scenarios. We conducted extensive studies to demonstrate the feasibility of the proposed techniques and illustrate the benefits of our approach in providing adaptive composite services using the policy-based approach. Our performance and scalability studies indicate that MASC middleware is scalable and the introduced overhead are acceptable.

Supporting ATAM with a collaborative web-based software architecture evaluation tool

As software companies are becoming increasingly globalised, a number of issues arise with respect to the social and environmental aspects of conducting the Architecture Tradeoff Analysis Method (ATAM), a software architecture evaluation method developed by the Software Engineering Institute. It would be fair to question the applicability of the ATAM to commercial companies. In this paper, we show that there are important issues and potential weaknesses in the ATAM from a social context. We provide suggestions for a means of overcoming these potential pitfalls through the assistance of the ubiquitous Internet. We then describe a tool dubbed ACE (ATAM Collaborative Environment), a Web-based software system that provides a common environment where stakeholders and software evaluators alike can take part in an ATAM evaluation without having to be physically collocated.

Enterprise application integration using a component-based architecture

Enterprise Application Integration (EAI) and Business-to-Business integration (B2B) leverage several key technologies including middleware and message brokers. However, an effective integration solution largely depends on the right combination of technologies that provide the glue between disparate applications. To build a technology infrastructure that can adapt to changes as the integration architecture evolves is crucial. The solution to the integration problem is forcing companies to think in distributed terms. In this paper, we show that a formula for successful deployment of an integrated organization is to have a technology infrastructure, consisting of a standard middleware and application server, that incorporates a distributed object infrastructure as well as platform to develop and integrate component-based applications. In particular, the paper evaluates the suitability of CORBA and EJBs as the enablers of EAI, and also the suitability of XML as a data definition and integration language.