SLAng: A language for defining service level agreements

Application or web services are increasingly being used across organisational boundaries. Moreover, new services are being introduced at the network and storage level. Languages to specify interfaces for such services have been researched and transferred into industrial practice. We investigate end-to-end quality of service (QoS) and highlight that QoS provision has multiple facets and requires complex agreements between network services, storage services and middleware services. We introduce SLAng, a language for defining Service Level Agreements (SLAs) that accommodates these needs. We illustrate how SLAng is used to specify QoS in a case study that uses a web services specification to support the processing of images across multiple domains and we evaluate our language based on it

Delivery of Personalized and Adaptive Content to Mobile Devices:A Framework and Enabling Technology

Many innovative wireless applications that aim to provide mobile information access are emerging. Since people have different information needs and preferences, one of the challenges for mobile information systems is to take advantage of the convenience of handheld devices and provide personalized information to the right person in a preferred format. However, the unique features of wireless networks and mobile devices pose challenges to personalized mobile content delivery. This paper proposes a generic framework for delivering personalized and adaptive content to mobile users. It introduces a variety of enabling technologies and highlights important issues in this area. The framework can be applied to many applications such as mobile commerce and context-aware mobile services

Building a SOA-Based Model for Purchase Order Management in E-Commerce Systems

Purchase Order Management (POM) is one of the most popular E-Commerce applications conducted between B2C and B2B systems. In many cases nowadays POM components use integration approaches that lack interoperability and manageability features. The purpose of this paper is to build a SOA based model for POM in E-Commerce system that achieves the goals of interoperability and manageability. In this paper a technical model of POM E-Commerce system is presented and analyzed. A new POM model based on SOA solution is proposed that overcomes the shortcoming of currently used model. The main contribution of this paper is to align a SOA-based model to the B2C and B2B E-Commerce domain

Using Process Technology to Control and Coordinate Software Adaptation

We have developed an infrastructure for end-to-end run-time monitoring, behavior/performance analysis, and dynamic adaptation of distributed software. This infrastructure is primarily targeted to pre-existing systems and thus operates outside the target application, without making assumptions about the target's implementation, internal communication/computation mechanisms, source code availability, etc. This paper assumes the existence of the monitoring and analysis components, presented elsewhere, and focuses on the mechanisms used to control and coordinate possibly complex repairs/reconfigurations to the target system. These mechanisms require lower level effectors somehow attached to the target system, so we briefly sketch one such facility (elaborated elsewhere). Our main contribution is the model, architecture, and implementation of Workflakes, the decentralized process engine we use to tailor, control, coordinate, etc. a cohort of such effectors. We have validated the Workflakes approach with case studies in several application domains. Due to space restrictions we concentrate primarily on one case study, briefly discuss a second, and only sketch others

TECHNOLOGICAL ENABLERS FOR PREVENTING SERVICE FAILURE WITH E-COMMERCE WEBSITES

Problems with digital services still occur at times, even for the most reliable services. Considering the consequences of these failures and their effects on the customer’s overall service quality perception and satisfaction, preventing these failures, and delivering reliable digital services, is a critical business competency. In addition, the fact that digital services are often co-produced by both service providers and their customers, shows the increasing role of both service providers and customers in preventing digital service failures (or service problems). In this study, we view the concept of digital service failure from the perspective of expectation-conformation theory, develop an Archimate architecture model and use it to design a typology of technological enablers (technologies and technological approaches) that can be used by businesses and their customers to prevent service failures at different stages of online purchase via e-commerce websites. The typology is relevant and useful for management information systems (MIS) academics and practitioners, particularly for information technology and digital service management researchers and the practitioner community

Web Content Delivery Optimization

Milliseconds matters, when they’re counted. If we consider the life of the universe into one single year, then on 31 December at 11:59:59.5 PM, “speed” was transportation’s concern, and now after 500 milliseconds it is web’s, and no one knows whose concern it would be in coming milliseconds, but at this very moment; this thesis proposes an optimization method, mainly for content delivery on slow connections. The method utilizes a proxy as a middle box to fetch the content; requested by a client, from a single or multiple web servers, and bundles all of the fetched image content types that fits into the bundling policy; inside a JavaScript file in Base64 format. This optimization method reduces the number of HTTP requests between the client and multiple web servers as a result of its proposed bundling solution, and at the same time optimizes the HTTP compression efficiency as a result of its proposed method of aggregative textual content compression. Page loading time results of the test web pages; which were specially designed and developed to capture the optimum benefits of the proposed method; proved up to 81% faster page loading time for all connection types. However, other tests in non-optimal situations such as webpages which use “Lazy Loading” techniques, showed just 35% to 50% benefits, that is only achievable on 2G and 3G connections (0.2 Mbps – 15 Mbps downlink) and not faster connections

A Reinforcement Learning Based Model for Adaptive ServiceQuality Management in E-Commerce Websites

Providing high-quality service to all users is adifficult and inefficient strategy for e-commerce providers,especially when Web servers experience overload condi-tions that cause increased response time and requestrejections, leading to user frustration and reduced revenue.In an e-commerce system, customer Web sessions havediffering values for service providers. These tend to: givepreference to customer Web sessions that are likely tobring more profit by providing better service quality. Thispaper proposes a reinforcement-learning based adaptivee-commerce system model that adapts the service qualitylevel for different Web sessions within the customer’snavigation in order to maximize total profit. The e-com-merce system is considered as an electronic supply chainwhich includes a network of basic e- providers used tosupply e-commerce services for end customers. The learneragent noted as e-commerce supply chain manager(ECSCM) agent allocates a service quality level to thecustomer’s request based on his/her navigation pattern inthe e-commerce Website and selects an optimized combi-nation of service providers to respond to the customer’srequest. To evaluate the proposed model, a multi agentframework composed of three agent types, the ECSCMagent, customer agent (buyer/browser) and service provideragent, is employed. Experimental results show that theproposed model improves total profits through costreduction and revenue enhancement simultaneously andencourages customers to purchase from the Websitethrough service quality adaptation

Combining Mobile Agents and Process-based Coordination to Achieve Software Adaptation

We have developed a model and a platform for end-to-end run-time monitoring, behavior and performance analysis, and consequent dynamic adaptation of distributed applications. This paper concentrates on how we coordinate and actuate the potentially multi-part adaptation, operating externally to the target systems, that is, without requiring any a priori built-in adaptation facilities on the part of said target systems. The actual changes are performed on the fly onto the target by communities of mobile software agents, coordinated by a decentralized process engine. These changes can be coarse-grained, such as replacing entire components or rearranging the connections among components, or fine-grained, such as changing the operational parameters, internal state and functioning logic of individual components. We discuss our successful experience using our approach in dynamic adaptation of a large-scale commercial application, which requires both coarse and fine grained modifications

Performance measurements of Web services

Web services are rapidly evolving application-integration technologies that allow applications in heterogeneous environments to communicate with each other. In this thesis we perform a measurements-based study of an e-commerce application that uses web services to execute business operations. We use the TPC-W specification to generate a session-based workload. The component level response times and the hardware resource usage on the different machines are measured. The component level response times are extracted from the application server logs. From the results it is seen that as the workload increases the response times of the web services components increase. From the hardware resource usage it is clear that web service components require more processing time due to the processing of XML data required in each web service call. The method used in this thesis allows us to study the impact that different components can have on the overall performance of an application