Exception Handling for Repair in Service-Based Processes (original) (raw)

Faults and recovery actions for self-healing web services

2006

Failures during Web service execution may depend on a wide variety of causes. In this paper we propose a classification of Web service faults, discussing three levels of faults, namely infrastructural & middleware, Web service, and Web application, and their mutual dependencies. In order to add selfhealing capabilities to Web service environments, possible recovery actions at the Web service and Web application levels are illustrated and discussed with respect to a running example involving coordinated Web services.

Towards a Self-Healing Approach to Sustain Web Services Reliability

2011

Web service technology expands the role of the Web from a simple data carrier to a service provider. To sustain this role, some issues such as reliability continue to hurdle Web services widespread use, and thus need to be addressed. Autonomic computing seems offering solutions to the specific issue of reliability. These solutions let Web services self-heal in response to the errors that are detected and then fixed. Self-healing is simply defined as the capacity of a system to restore itself to a normal state without human intervention. In this paper, we design and implement a self-healing approach to achieve Web services reliability. Two steps are identified in this approach: (1) model a Web service using two behaviors known as operational and control, and (2) monitor the execution of a Web service using a control interface that sits between these two behaviors. This control interface is implemented in compliance with the principles of aspect-oriented programming and case-based reasoning.

Modeling Architectural Level Repair in Web Services

Proceedings of the Third International Conference on Web Information Systems and Technologies, 2007

Failures during Web service execution may depend on a wide variety of causes, such as network faults, server crashes, or application-related errors, such as unavailability of a requested Web service, errors in the orchestration or choreography of applications, missing data or parameters in an execution flow, or low Quality of Service (QoS). Providing efficient solutions requires handling adaptability not only at the behavioral level, but also at the architectural level. Most of existing standard solutions focus on the behavioral level using reconfiguration mechanisms. In this paper, we propose a model-based approach providing adaptability actions at the architectural level. Typical architectural reconfiguration actions, such as duplication of services or substitution of a non conforming service are introduced. An example is illustrated and discussed with respect to a running example involving coordinated Web services. a. a This work has been funded by the IST WS-DIAMOND European project.

Automated self-healing framework for service-oriented systems

2013 ACS International Conference on Computer Systems and Applications (AICCSA), 2013

In this paper, we propose a technique for serviceoriented architectures (SOA) to dynamically evaluate the performance of Web services based on their previous history, and user requirements. The likelihood of fault occurrence is then used to create recovery plans. The 'best' recovery plan is then chosen to be either executed immediately, or saved for a later execution. We assess the overall system dependability using the generated plan and the available invocation information of the included services. Experiment results indicate the applicability of our technique, and show the improved performance in comparison with similar existing approaches.

On Modeling and Developing Self-Healing Web Services Using Aspects

2007

Like any computing application, Web services are subject to failure and unavailability due to multiple reasons like Web service faulty-code and unreliable communicationinfrastructure. A manual correction of Web services failure is error-prone and time-consuming. An effective Web services environment should be able to monitor its state, diagnosis faults, and automatically recover from failures. This process is known as self-healing. In this paper, we address self-healing issues of Web services using Aspect-Oriented Programming (AOP). AOP supports separation of self-healing concerns from Web services code and promotes maintenance and reusability.

Model-Based QoS-Enabled Self-Healing Web Services

2008 19th International Conference on Database and Expert Systems Applications, 2008

Failures during web service execution may depend on a wide variety of causes, such as network faults, server crashes, or application-related errors, such as unavailability of a requested web service, errors in the orchestration of choreography of applications, missing data or parameters in an execution flow, or low Quality of Service (QoS). In this paper, we propose a healing architecture able to handle web service faults in a selfhealing way, discussing infrastructural faults and web service and Web application faults. The self-healing architecture manages repair actions, such as substitution of a faulty service or duplication of overloaded services. Implemented prototypes involving QoS in coordinated web services are illustrated and discussed. 1

Fault-Tolerant Business Processes

2011

Service-oriented computing (SOC) paradigm promotes the idea of assembling application components into a network of loosely coupled services. Web services are the most promising SOC-based technology. A BPEL process definition represents a composite service that encapsulates some complex business logic including the invocation to other (external) web services. The complexity of a BPEL process together with the invocation of external services subject to network and computer failures requires countermeasures to tolerate this kind of failures. In this paper we present an overview of FT-BPEL, a fault-tolerant implementation of BPEL that copes both with failures of the machine running the BPEL process and network failures in a transparent way, that is, after a failure the system is able to resume the BPEL process consistently.

Adding Self-healing Behaviour to Dynamic Web Service Composition

2006

The dynamic nature of the Web imposes the automation of web service compositions. Since these compositions serve high level business purposes, it is mandatory to address the reliability issue. The autonomic computing paradigm, introduced by IBM, offers a guideline for building self-managing systems. An important principle of this paradigm is the self-healing behaviour which represents the ability of a system to recover from faulty situations. This paper investigates how to increase the reliability of automatic web service compositions by proposing a framework for adding self-healing behaviour. First, we analyze the general domain of autonomic web services and then, we propose a formal description and architecture for adding self-healing behaviour to web service compositions.

On the enhancement of bpel engines for self-healing composite web services

Applications and the …, 2008

The dynamic nature of the Internet poses various challenges to the successful execution of composite Web services. Failures are samples of these challenges. It needs to be addressed for the smooth progress of Web service composition. Unfortunately, the de facto standard for modeling composition namely BPEL is not equipped with mechanisms that let Web services "heal" themselves in case of failures. In addition, current BPEL engines lack appropriate facilities that permit satisfying self-healing requirements like handling in a transparent way functional failures of component Web services during runtime. This paper presents an approach for enhancing BPEL engines with such facilities. This enhancement happens through the following steps: identify possible categories of failures, develop solutions to automatically recover from these failures, and suggest architectural extensions to BPEL engines (with focus on ActiveBPEL) to support these solutions. We also present a proof-of-concept prototype that illustrates our ideas.