WS-replication: a framework for highly available web services (original) (raw)
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Proceedings of the 15th international conference on World Wide Web - WWW '06, 2006
Due to the rapid acceptance of web services and its fast spreading, a number of mission-critical systems will be deployed as web services in next years. The availability of those systems must be guaranteed in case of failures and network disconnections. An example of web services for which availability will be a crucial issue are those belonging to coordination web service infrastructure, such as web services for transactional coordination (e.g., WS-CAF and WS-Transaction). These services should remain available despite site and connectivity failures to enable business interactions on a 24x7 basis. Some of the common techniques for attaining availability consist in the use of a clustering approach. However, in an Internet setting a domain can get partitioned from the network due to a link overload or some other connectivity problems. The unavailability of a coordination service impacts the availability of all the partners in the business process. That is, coordination services are an example of critical components that need higher provisions for availability. In this paper, we address this problem by providing an infrastructure, WS-Replication, for WAN replication of web services. The infrastructure is based on a group communication web service, WS-Multicast, that respects the web service autonomy. The transport of WS-Multicast is based on SOAP and relies exclusively on web service technology for interaction across organizations. We have replicated WS-CAF using our WS-Replication framework and evaluated its performance.
High Availability with Clusters of Web Services
2004
Internet is open 24 hours a day, 7 days a week, so hardware, software, and communications must be always online. Additionally, the total number of users and its workload is completely unpredictable. If you decide to use web services, you will have no solution for problems like those. This paper shows a new technique that can be applied to web services technology in order to be able to deploy web services with high availability features using clustering. This new technique is based on the virtualization of the real web services used to serve the client requests, creating new virtual web services that will be the ones invoked by the clients. At the back-end, the implementation web services (the real ones) will be invoked inside a cluster.
Making Web Services Dependable
2006
Web services offer great promise for integrating and automating software applications within and between enterprises over the Internet. However, ensuring that Web services are dependable, and can satisfy their clients' requests when the clients need them is a real challenge because, typically, a business activity involves multiple Web services and a Web service involves multiple components, each of which must be dependable. In this paper, we describe fault tolerance techniques, including replication, checkpointing, and message logging, in addition to reliable messaging and transaction management for which Web services specifications exist. We discuss how those techniques can be applied to the components of the Web services involved in the business activities to render them dependable.
A Generalized Service Replication Process in Distributed Environments
Replication is one of the main techniques aiming to improve Web services’ (WS) quality of service (QoS) in distributed environments, including clouds and mobile devices. Service replication is a way of improving WS performance and availability by creating several copies or replicas of Web services which work in parallel or sequentially under defined circumstances. In this paper, a generalized replication process for distributed environments is discussed based on established replication studies. The generalized replication process consists of three main steps: sensing the environment characteristics, determining the replication strategy, and implementing the selected replication strategy. To demonstrate application of the generalized replication process, a case study in the telecommunication domain is presented. The adequacy of the selected replication strategy is demonstrated by comparing it to another replication strategy as well as to a non-replicated service. The authors believe that a generalized replication process will help service providers to enhance QoS and accordingly attract more customers.
IMPROVING QUALITY OF WEB SERVICES BY USING REPLICATION
2008
ABSTRACT Web services define a kind of middleware for implementing distributed applications independent of underlying platforms and used programming languages. In the development of new software systems, functionality of existing services can be re-used to reduce development time and costs. This process of re-use can be done by web service composition.
Coordinated Web Services Orchestration
process definition the sequence of exchanged messages typically originates from the sequence of business process activities and from the need of coordination of those activities across the participants of the process. As such business concerns (e.g. the sequence of business process steps) are often mixed with technical aspects (e.g. the sequence of coordination messages). In this article we present an architecture to separate business and technical concerns, which results in a clearer overview of the high-level business process and improves the flexibility and maintainability of the orchestration architecture. The described architecture depends on existing Web service standards. Different eventing and coordination specifications are discussed. The ultimate architecture is mainly based on the WS-Brokered Notification and WS-Coordination Framework specifications.
A Lightweight Fault Tolerance Framework for Web Services
2007
In this paper, we present the design and implementation of a lightweight fault tolerance framework for Web services. With our framework, a Web service can be rendered fault tolerant by replicating it across several nodes. A consensusbased algorithm is used to ensure total ordering of the requests to the replicated Web service, and to ensure consistent membership view among the replicas. The framework is built by extending an open-source implementation of the WS-ReliableMessaging specification, and all reliable message exchanges in our framework conform to the specification. As such, our framework does not depend on any proprietary messaging and transport protocols, which is consistent with the Web services design principles. Our performance evaluation shows that our implementation is nearly optimal and the framework incurs only moderate runtime overhead.
Ftweb: A fault tolerant infrastructure for web services
EDOC Enterprise Computing …, 2005
The web services architecture came as answers to the search for interoperability among applications. In recent years there has been a growing interest in deploying on the Internet applications with high availability and reliability requirements. However, the technologies associated with this architecture still do not deliver adequate support to this requirement. The model proposed in this article is located in this context and provides a new layer of software that acts as a proxy between client requests and service delivery by providers. The main objective is to ensure client transparent fault tolerance by means of the active replication technique. This model supports the following faults: value, omission and stops. This paper describes the features and outcomes obtained through the implementation of this model.
Providing dependability for web services
Proceedings of the 2008 ACM symposium on Applied computing - SAC '08, 2008
Web services have been widely employed to allow interoperability among applications and/or technologies. However, the standard technologies and protocols which provide the foundation for Web Services do not address issues such as fault tolerance and dependability of services. Aiming to solve this limitation, this paper proposes a software architecture for providing dependability for Web Services. This architecture is responsible for increasing service availability and maintaining all replicas of a service in a consistent state, having as main characteristic the separation of these replicas in groups.
DeW: A Dependable Web Services Framework1
2003
Physical-location-independence means a plan will execute as long as a copy of its referenced WSs is available. This concept enables the client proxy objects to continue operation in the presence of both failures and WS migrations that balance system load.