Amal Alhosban

WebNeg: A Genetic Algorithm Based Approach for Service Negotiation

Automated negotiation among Web services not only provides an effective way for the services to bargain for their optimal customizations, but also allows the discovery of overlooked potential solutions. A number of negotiation supporting techniques have been used to find solutions that are acceptable to all parties in the negotiation. However, employing these solutions for automated negotiations among Web services has its own challenges. In this paper, we present the design of a Negotiation Web service that would be used by both the consumers and providers of Web services for conducting negotiations. This negotiation service uses a genetic algorithm(GA) based approach for finding acceptable solutions in multi-party and multi-objective negotiations. In addition to the traditional genetic operators of crossover and mutation, the search is enhanced using anew operator called the Norm. Norm operator represents the cumulative knowledge of all the parties involved in the negotiation process. GA performance with the new Norm operator is compared to the traditional GA, hill-climber and random search techniques. Experimental results indicate the practicality of our approach in facilitating the negotiations involved in a Web service composition process. Specifically, the proposed GA with Norm operator performs better than other approaches.

Automated Negotiation Among Web services

Automated negotiation among Web services not only provides an effective way for the services to bargain for their optimal customizations, but also allows the discovery of overlooked potential solutions. A number of negotiation supporting techniques have been used to find solutions that are acceptable to all parties in the negotiation. However, employing these solutions for automated negotiations among Web services has its own challenges. In this chapter, we present the design of a Negotiation Web service that would be used by both the consumers and providers of Web services for conducting negotiations. This negotiation service uses a genetic algorithm (GA) based approach for finding acceptable solutions in multi-party and multi-objective negotiations. In addition to the traditional genetic operators of crossover and mutation, the search is enhanced using a new operator called the Norm. Norm operator represents the cumulative knowledge of all the parties involved in the negotiation process. GA performance with the new Norm operator is compared to the traditional GA, hill-climber and random search techniques. Experimental results indicate the practicality of the approach in facilitating the negotiations involved in a Web service composition process. Specifically, the proposed GA with Norm operator performs better than other approaches.

Bottom-Up Fault Management in Service-Based Systems

Service Oriented Architecture (SOA) enables the creation of distributed applications from independently developed and deployed services. As with any component-based system, the overall performance and quality of the system is an aggregate function of its component services. In this article, we present a novel approach for managing bottom-up faults in service-based systems. Bottom-up faults are a special case of system-wide exceptions that are defined as abnormal conditions or defects occurring in component services, which if not detected and/or managed, may lead to runtime failures. Examples of bottom-up faults include network outage, server disruption, and changes to service provisioning (e.g., new operation parameter required) that may have an impact on the way component services are consumed. We propose a soft-state signaling-based approach to propagate these faults from participants to composite services. Soft-state refers to a class of protocols where the state of a service is constantly refreshed by periodic messages, and user/service takes up the responsibility of communicating and maintaining its state. Soft-state-based protocols have a number of advantages including implicit error recovery and easier fault management, resulting in high availability for systems. Although soft-state has been widely used in various Internet protocols, this work is the first (to the best of our knowledge) to adopt soft-state for fault management in composite services. The proposed approach includes protocols for fault propagation (pure soft-state and soft-state with explicit removal) and fault reaction (rule-based). We also present experiment results to assess the performance and applicability of our approach.

A Web Service Negotiation Management and QoS Dependency Modeling Framework

Information Management Systems that outsource part of the functionality to other (likely unknown) services need an effective way to communicate with these services, so that a mutually beneficial solution can be generated. This includes bargaining for their optimal customizations and the discovery of overlooked potential solutions. In this article, we present an automated negotiation framework for information systems (denoted as WebNeg) that can be used by both the parties for conducting negotiations. WebNeg uses a Genetic Algorithm (GA)-based approach for finding acceptable solutions in multiparty and multiobjective scenarios. The GA is enhanced using a new operator called Norm, which represents the cumulative knowledge of all the parties involved in the negotiation process. Norm incorporates the dependencies of different quality attributes of independently developed component services for the system composition. This enables WebNeg to find a better solution in the context of the current requirements. Experiment results indicate the applicability and improved performance of WebNeg (in comparison with existing similar works) in facilitating the negotiation management involved in a web service-based information composition process.

Automated Negotiation Using Semantic Rules

With the extensive adaptation of Web service based applications in dynamic businesses applications including on demand computing, highly configurable virtual solutions and cloud computing based systems demand automated tools for composing and managing these services in composite systems. The use of standard protocols for publishing, discovery, invocation, process definition and SLA definition etc. (e.g. UDDI, WSDL, SOAP, BPEL, WS-Agreement, WS-Policy) has made it possible to compose highly usable composite systems with minimal efforts. On the other hand the existence of a number of functionally equivalent service provide the system designers with the flexibility of choosing the most appropriate services for the system. Hence, automated negotiation among Web services provides an effective way for the services to bargain for their optimal customizations and allow the discovery of overlooked potential solutions. In this paper, we present a Web service negotiation framework that would be used by both the customer and providers of Web services for conducting automated negotiations for quality of service properties of Web services. Our proposed framework is highly flexible, protocol independent and supports participant polices for communication, negotiation and service level agreement creation. We further extend our approach by extending WS-Negotiation and WS-Renegotiation to model multi-round negotiation for multiple attributes of negotiated services in a multi-service and multi-party negotiation scenarios. We also describe a semantic web rules based approach for converting compatible participant policies for mutual comprehension of Web service. We describe in detail the process of negotiating service level agreements using the semantic web rules based approach.

Dependency modeling in automated web services quality component negotiations

Web services are a popular choice for component oriented systems that support dynamic compositions. Automated negotiation among Web services provides an effective way for the services to bargain for their optimal customizations and allows the discovery of overlooked potential solutions. Unique and dynamic Quality of Service (QoS) requirements of service consumers pose challenges for effective approaches of service compositions with multiple QoS parameters. In this paper, we present a negotiation Web service that would be used by both the consumer and provider Web services for conducting negotiations for dependent QoS parameters. We use a genetic algorithm(GA) based approach for finding acceptable solutions in multi-party and multi-objective scenarios. Experimental results indicate the applicability and improved performance or our approach in facilitating the negotiations involved in a Web service composition process.

GFDA: Route Discovery Algorithms for On-demand Mobile Ad Hoc Routing Protocols

Abstract Route discovery in manymobile ad hoc protocols is based on flooding. However, flooding suffers from high overhead, which can increase contention and communication delays. In this paper,we propose twonewroute discovery algorithms that are aimed towards reducing these delays. Both algorithms are suitable for use with ad hoc protocols where nodes periodically broadcast Hello Messages. Using the GloMoSim simulator, the proposed algorithms were evaluated and compared to existing methods. The simulation results show that the proposed approach can reduce routing overhead, number of broken links, average delay, and the number of dropped packets. Small improvements in message delivery ratios are also observed.

Automated Web service quality component negotiation using NSGA-2

Web services are a popular choice for component oriented systems. Web services not only provide a platform independent architecture but also support dynamic compositions to facilitate on the fly creation of composite solutions. Automated negotiation among Web services provides an effective way for the services to bargain for their optimal customizations and allows the discovery of overlooked potential solutions. Dynamic and unique Quality of Service (QoS) requirements of diverse service consumers, pose challenges for effective approaches of service compositions with multiple QoS parameters. In this paper, we present a negotiation Web service that would be used by both the consumer and provider Web services for conducting negotiations for dependent QoS parameters. We use a genetic algorithm(GA) based approach for finding multiple Pareto optimal solutions in multi-party and multi-objective negotiation scenarios, that may satisfy users requirements. Experimental results indicate the applicability of or our approach in facilitating the negotiations involved in a Web service composition process.

A bat algorithm based approach of QoS optimization for long term business pattern

Business process automation using software as a service is well accepted software deployment and distribution model that is grown exponentially in the last few years. SaaS can provide solutions that are suitable for both one off as well as long running systems. Multiple component services are combined to formulate a composite solution. This modular nature of the systems allows the flexibility to replace faulty services or introduce better performing components into the initial solution. On the other hand it makes it easier to deal with situations where a long running system may need to deal with a service which is no longer available or has a competitor which offers similar to better service as a much more attractive package. To fully utilize this nature of the software we need to understand the structure of the system. In this paper we present a bat algorithm based solution for different Quality of Service parameters of a component service considering the different invocation patterns of these component services in the system for optimum values of the QoS parameters. We evaluate the efficiency of our proposed technique on WSDream-QoSDataset [20] and show its effectiveness.

FT-SOA: A Failure-Prediction Technique in Service-Oriented Systems

A modern organizations day to day operations rely heavily on the proper functioning of its IT systems. Increasingly, most of these systems are starting to be based on the Service Oriented Architectures (SOAs). SOAs enable the automatic creation of business applications from independently developed and deployable Web services. When a SOA component suffers failure it results in sub-par operational performance and ultimately hampers the revenue stream of the organization. There are two approaches to minimize the failure risk in SOA: (a) Fault Intolerance tries to eliminate the faults before it occurs in a system. (b) Fault-Tolerance techniques deal with faults that occur on run time and try averting that faults from turning into system failures. Most of the current fault management techniques focus on the latter. However, in our study we develop a hybrid model. The method proposed in this paper (FT-SOA) predicts the failure based on HSMM and clustering techniques for SOAs and Web services. We focus on failure prediction because it plays a major role in having a highly available system. The objective of the online fault prediction is to predict the occurrence of faults in the system, based on the current information such as: service weight, previous history and reputation. A new prediction method is created to assess the fault likelihood in the near future execution of a specific service in a composite solution. We compare our approach with similar techniques to show the applicability of our approach.