Casey K. Fung

Integrated quality of service (QoS) management in service-oriented enterprise architectures

One of the significant challenges for making service-oriented architectures (SOA) effective for enterprise systems is quality of service (QoS) management because of the dynamic, flexible, and compositional nature of SOA. QoS management must be integrated into service-oriented enterprise architectures. It must support a set of common QoS characteristics and provide comprehensive QoS services end to end, from application, to middleware, and to network and from source hosts to destination hosts across a network. We describe such an integrated QoS management architecture and its services. We classify QoS characteristics into four categories and each of which is decomposed into a set of measurable attributes. We integrate these characteristics into an XML-based language for applications and QoS providers to express QoS requirements and contracts. We model an integrated QoS management architecture based on standard specifications from organizations like ISO and OMG. We implement a comprehensive set of QoS management services with innovation resource management techniques and adaptation mechanisms. We provide test data to validate our architecture and solution first in a publish/subscribe style of enterprise SOA. In comparison with other work in QoS management, our architecture and solution provide innovative techniques, extensions, and generalizations beyond traditional task-oriented QoS management in object-oriented middleware and domain specific applications.

A semantic infosphere

We describe a prototype implementation of a semantic filtering capability added to an existing XML-based publish and subscribe infrastructure. An ontology is used to provide vocabulary for expressing both 1) the semantic annotations that characterize the published documents and 2) the subscriptions specifying the class of documents to be routed to a given client. A description logic (DL) classifier is used to determine which subscribers an incoming document is routed to. We outline the key elements of the ontology for the battlefield domain and give some sample annotations and subscriptions. This is the basis for describing a number of scenarios showing how this filtering capability could be used practice. We critically analyze the suitability of a DL language and reasoner in general, and the particular implementation choices (DAML+OIL, FaCT and OilEd) for performing this task. A key result of the work is to demonstrate the importance of testing semantics-based technologies on practical problems. We discovered a number of new and interesting areas for future work, which in turn can direct the focus of the research community.

A Service-Oriented Composition Framework with QoS Management

Quality of Services (QoS) management in compositions of services requires careful consideration of QoS characteristics of the services and effective QoS management in their execution. This paper describes an approach to implementation of QoS management in compositions of Web services in the context of Computational Quality Attributes and Service Level Agreements. Building on prior research work of others in the use of Message Detail Records, this paper integrates the results from several research threads to propose a QoS Management Architecture to support dynamic processing of service- and flow level quality attributes to support QoS requests and analyses in Web-service-oriented architectures. The study of QoS management in a Web service composition framework was motivated by the evolution of the composition framework for a toolkit for integration and experimentation of distributed system applications. A message tracking model is proposed for supporting QoS end-to-end management by applying the Computational Quality Attribute (CQA) concepts of Flow-Service-Quality engineering. Quality attributes are defined, computed and acted upon as dynamic characteristics of systems, with values constantly changing in operation. A CQA provision is illustrated, with a simple Web Services travel reservation example. The example is elaborated to illustrate QoS end-to-end management using the Simple Object Access Protocol (SOAP) message tracking model.

A study of service composition with QoS management

Quality of service (QoS) management in compositions of services requires careful consideration of QoS characteristics of the services and effective QoS management in their execution. A Web service is a software system that supports interoperable application-to-application interaction over the Internet. Web services are based on a set of XML standards such as simple object access protocol (SOAP). The interactions of SOAP messages between Web services form the theoretical model of SOAP message exchange patterns (MEP). Web Services Business Process Execution Language (WSBPEL) defines an interoperable integration model that facilitates automated process integration in intra- and inter-corporate environments. A service-level agreement (SLA) is a formal contract between a Web services requestor and provider guaranteeing quantifiable issues at defined levels only through mutual concessions. Based on a prior research work on message detail record (MDR), this paper further proposes a SOAP message tracking model for supporting QoS end-to-end management in the context of WSBPEL and SLA. This paper motivates the study of QoS management in a Web service composition framework with the evolution of a distributed toolkit in an industrial setting.

Achieving survivability in business process execution language for Web services (BPEL) with exception-flows

Survivability is defined as the capability of a service to fulfill its mission in a timely manner, even in the presence of attacks, failures, or accidents. Because of the severe consequences of failure, organizations are focusing on service survivability as a key risk management strategy for business processes. There are three key survivability properties: resistance, recognition, and recovery. Recovery, a hallmark of survivability, is the capability to maintain critical components and resource during attack, limit the extent of damage, and restore full services following attack. Exception handling is a way to deals with the recovery aspect of survivability. Business process execution language for Web services (BPEL) has been proposed for formal specification of business processes and interaction protocols. BPEL defines an interoperable integration model that facilitates expansion of automated process integration in both intra- and intercorporate environments. A business process description requires the specification of both the normal flow and the possible variations due to exceptional situations that can be anticipate and monitored. This paper bridges the analysis of business process survivability and its recovery aspect in terms of exception handling in the context of BPEL. The feasibility of the proposed model is demonstrated using an illustrative travel reservation example.

Evolution of composition framework in a distributed system toolkit

Network Centric Information Infrastructure (NCII) is a toolkit of prefabricated software components together with a composition framework for integration and experimentation. Typical distributed system applications of a toolkit such as NCH can be applied to air traffic management, shop floor control and in-flight connection to Internet. The composition framework has gone though through three generations of changes in the past five years and it is a good illustration of a paradigm shift from object-oriented architecture, through component-based architecture to service-based architecture.

Dynamic Regeneration of Workflow Specification with Access Control Requirements in MANET

Distributed software systems are the basis for innovative applications. The key for achieving survivable and maintainable distributed systems is agility because the non-deterministic nature of distribution would otherwise leave the system uncontrollable, especially in emerging mobile ad-hoc networks. A mobile ad-hoc network (MANET) is based on a self-organizing and rapidly deployed network of mobile services to collaborate without using any pre-existing fixed network infrastructure. Survivability is defined as the capability of a service to fulfil its mission in a timely manner, even in the presence of attacks, failures, or accidents. There are four key survivability properties: resistance, recognition, recovery and adaptation. Recovery, a hallmark of survivability, is the capability to maintain critical components and resource during attack, limit the extent of damage, and restore full services following attack. Exception handling is a way to deal with the recovery aspect of survivability. Resistance can be viewed as the process of limiting access to critical and vulnerable resources only to authorized users, programs, processes, or other systems. This paper bridges the analysis of secure business process and its recovery aspect in terms of exception handling in the context of access control requirements. We propose an integrated approach to engineer a survivable distributed system through dynamic regeneration of workflow specifications in the context of Business Process Execution Language for Web Services (BPEL) and eXtensible Access Control Markup Language (XACML)

Information and knowledge management in online rich presence services

Nowadays many information technology services are moving towards online via ubiquitous networks, computing and information at unlimited speed anytime and anywhere with different kinds of technical platforms, especially in Web 2.0. In general, presence information expresses user willingness and ability to communicate with other users across a set of services for real-time communications. Web 2.0 uses the Web as a platform for embracing the interconnectivity and interactivity of Web-delivered content among different online users and communities, which have recently been assumed by the technology of services computing such as Web services. Web services are based on a set of XML standards such as Universal Description, Discovery and Integration (UDDI), Web Services Description Language (WSDL), Simple Object Access Protocol (SOAP), Business Process Execution Language for Web Services (BPEL4WS), and etc. The rapid development of Web 2.0 for massive social network collaboration facilitates the “rich presence services” to expose information and knowledge gathered through online social networks which assists intelligent decision making and analysis. Rich presence is described as an enhanced form of presence awareness in which a service can observe other online service/user attributes, such as personal identifiable information, location, time, behavior, movement, type-of-software, type-of-device, and type-of-network. The use of Web 2.0 technologies may generate both user-generated content as well as contextual information about users, for example, their current location and availability. Rich presence also refers to the aggregation of this information that makes presence attributed to consenting services available for use by other services/users. This result generates a consolidation of virtual, physical, and online services into a single richpresence platform based on content-based publish/subscribe services for efficient filtering and dissemination of presence information. Online rich presence services divulge only the availability of other services. In this context, knowledge management comprises a range of strategies and practices used in an online rich presence service to create, manage, coordinate, distribute, and enable adoption of information. Such information comprises knowledge, either embedded in services or embedded in business processes, focuses on organizational quality of services (QoS) objectives such as performance, and competitiveness. Therefore, this special issue aims to examine the information and knowledge management model in this emerging context for the next generation applications. All the 8 papers in this issue will have deep research results to report the advance of online rich presence services such as information discovery, knowledge management, recommendation and collaborative filtering, services compositions, supply chain management, trust framework, grid and cloud computing. In the first paper “Feasilibility and A Case Study on Content Optimization Services on Cloud” (Wong 2013), Wong focuses on content optimization services that modify and reorganize content to reduce the size of content and enhance the performance of processing on the content. Wong presents the economics related to these services with practical considerations when these services are implemented on a cloud, which is typically perceived to be a more economical and scalable option compared to traditional dedicated servers. C. K. Fung Boeing Research and Technology, Seattle, WA, USA e-mail: casey.k.fung@boeing.com

Dynamic Workflow Generation with Interoperable Security Alerts in MANET

Distributed software systems are the basis for innovative applications. Agility is the key for achieving survivable and maintainable distributed systems because the non-deterministic nature of distribution would otherwise leave the system uncontrollable, especially in emerging mobile ad-hoc networks. A mobile ad-hoc network (MANET) is based on a self-organizing and rapidly deployed network of mobile services that collaborate without using any preexisting fixed network infrastructure. Survivability is defined as the capability of a service to fulfill its mission in a timely manner, even in the presence of attacks, threats, or failures. Any failure of a single system may affect a business process; however, the monitoring of many mobile services simultaneously is not an easy task. This paper bridges the analyses of business processes and security threats with an alert mechanism. We propose an integrated approach to engineer a survivable distributed system through dynamic workflow generation in the context of Web Services Business Process Execution Language (WSBPEL), and Really Simple Syndication (RSS).