Guijun Wang

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.

Service level management using QoS monitoring, diagnostics, and adaptation for networked enterprise systems

As enterprise services increasingly interconnect as networked services in a service-oriented architecture (SOA), service level management (SLM) is becoming a complex problem and can no longer be handled by traditional monitoring tools like Microsoft SMS. SLM is a process managing the quality of services demanded by clients and offered by providers. This paper presents two contributions to the research of SLM. First, instead of considering monitoring as an isolated service, it incorporates monitoring as an integral part of a comprehensive QoS management framework. This framework consists of QoS management concepts and services including service level contract management, admission control, resource management, monitoring, diagnostics, and adaptation. Using this framework, clients are able to negotiate quality of service contracts with providers and providers are able to optimize system resources to meet contract requirements. The second contribution is the incorporation of diagnostic service in the QoS management framework. Based on data feed from monitoring service, diagnostic service is able to detect any condition changes and to reason about the causes of any degradation conditions in the networked enterprise system. With condition detection and situation understanding, QoS management can then proactively activate adaptation mechanisms to maximize the systems ability to meet QoS contract requirements of concurrent clients. Our monitoring service uses both reporting approach and probing approach to acquire the information of the health status of elements of a networked system. The monitored data is then fed to our diagnostic service to reason about root causes of anomalies, using graphical models. Depending on the system health status and root causes, appropriate adaptations are triggered proactively to improve the system performance under the constraints of concurrent QoS contracts. We validate our SLM approach using QoS management services integrated in a publish/subscribe style of SOA. We then demonstrate via experiments some benefits of QoS monitoring, diagnostics, and adaptation services for responsiveness SLM.

A policy-based approach for QoS specification and enforcement in distributed service-oriented architecture

A significant challenge of successful application of the service-oriented architecture (SOA) in large-scale distributed systems is the quality of service (QoS) management, which provides various QoS guarantee levels for concurrent clients through effective resource allocations and adaptations. In this paper, we propose a policy-based approach for specifying QoS management strategies and enforcing QoS guarantees. This approach enables easy adaptation of new business rules and adaptation to system resource changes. This approach is also effective for supporting QoS management, as demonstrated in our experiments in a publish/subscribe system.

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.

A Multi-Layer Security Enabled Quality of Service (QoS) Management Architecture

Service-oriented architectures are dynamic, flexible and compositional in nature. Security and Quality of Service (QoS) management are two significant challenges for Service-Oriented-Architectures (SOA) in a multi-domain environment. We have researched and developed a SOA based QoS framework architecture and implemented a facility according to the architecture. This facility implementation consists of a set of QoS management services with XML-based policy driven resource management techniques, monitoring and diagnostics, and adaptation mechanisms. It is built on a publish/subscribe based middleware and has been successfully demonstrated in an enterprise testbed environment. We have expanded the QoS architecture to include QoS Security characteristics that incorporates the concept of Multi- Level Security (MLS). We call this expanded architecture a QoS-MLS architecture. This architecture addresses the security and QoS challenges in a coherent and integrated approach for enterprise SOA. In this paper we describe this QoS- MLS architecture which is the result of the integration of MLS into a QoS Management facility at the middleware layer.

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.

Intelligent aggregation of purchase orders in e-procurement

A large enterprise generates millions of purchase orders (PO) each year buying various types of goods and services. Each PO has a cost associated with it. This cost comprises multiple elements including the price of the good or service, the shipping and handling of the purchase, and the overhead in initiating, generating, tracking, and managing the PO. To reduce the cost of doing business, it is imperative to reduce the total cost of POs in enterprise e-procurement in an automated fashion. One way to reduce enterprise procurement cost is to aggregate demands so that the total cost of a bunch of POs is reduced by a better price, a lowered shipping and handling fee, and a reduced overhead. The cost of goods and services often depend on several factors including volume, timing, and other business objectives. This paper describes an intelligent aggregation approach for automatically aggregating demands to reduce procurement cost in enterprise e-procurement. Our aggregation approach for e-procurement consists of an information model for representing products (goods or services) and representing purchase orders for such products, a corporate agreement system, a negotiation engine, and a rule-based aggregation engine. The information model is based on an extension of the classic entity-relationship model. The extension enables association of rules and constraints with and among attributes. These rules and constraints must be satisfied during PO aggregation and thus ensure the aggregate PO to be consistent with original individual POs. A rule-based aggregation engine examines POs as they arrive and interact with other decision aids to determine whether aggregation of a particular bunch of POs makes any business sense. Aggregation can happen in two business scenarios, one for POs constrained by existing corporate agreements and another for POs to be refined by online negotiations. The aggregation engine interacts with a corporate agreement system to obtain supplier policies in the first scenario. For the second scenario, it interacts with the negotiation engine to obtain suppliers policies during iterations of the negotiation process. Relevant policies are those that define product pricing, shipping and handing, and post-sale sendees as well as warranties and returns. Examples are given to demonstrate how automated intelligent aggregation of purchases is performed and how it reduces cost in enterprise e-procurement.

Service Level Management in Global Enterprise Services: from QoS Monitoring and Diagnostics to Adaptation, a Case Study

We developed a quality of service (QoS) management system to support service level management (SLM) for global enterprise services. The QoS management system is integrated with one of our enterprise services in a preproduction system, an identical system as the production system but in a test environment. Lab experiments showed that our integrated solution helps global enterprise services to better maintain the service level agreements. Test results have validated our architecture design and integration approach. This paper describes our QoS management architecture and its integration within the enterprise service system with a focus on QoS monitoring, diagnostics and adaptation. We will also present the validation test results as a case study in this paper.

Message from the AQuSerM 2011 Chairs

The Advances in Quality of Service Management (AQuSerM) workshop is a satellite event of the IEEE International EDOC Conference (EDOC 2011). The AQuSerM workshop was established as a forum for presenting advances in QoS-oriented techniques and tools for managing enterprise architectures, encompassing approaches to monitoring, diagnostics, runtime analysis and prediction and adaptation. Modeldriven approaches are a special focus of the workshop.