Transparent Fault Tolerance for Web Services based Architectures

Service-based architectures enable the development of new classes of Grid and distributed applications. One of the main capabilities provided by such systems is the dynamic and flexible integration of services, according to which services are allowed to be a part of more than one distributed system and simultaneously serve different applications. This increased flexibility in system composition makes it difficult to address classical distributed system issues such as fault-tolerance. While it is relatively easy to make an individual service fault-tolerant, improving fault-tolerance of services collaborating in multiple application scenarios is a challenging task. In this paper, we look at the issue of developing fault-tolerant service-based distributed systems, and propose an infrastructure to implement fault tolerance capabilities transparent to services.

Meaningful UDDI web services description

There is a lack of meaningful description of Web Services in UDDI, however, it is necessary for automatic services discovery. In this paper, a language is proposed for semantics description of Web Services which complements the UDDI standards to derive relationships among Web Services. The semantics description can be used to automatically derive relationships among Web Services. We describe how the semantics description of Web Services, based on the proposed language, can be integrated with UDDI.

Agents for invocation of web services

Web services are becoming popular and widely accepted on the Internet. UDDI is the standard for publishing and discovery of web services. In this paper, we investigate semantics description of web services based on domain ontology; based on this language, we propose an architecture for invoking agents to consume services within the UDDI registry. The semantics service description language together with agent creation
architecture provides a new way to discover and utilise published web services. This method is flexible and extendable to accomplish complex web service requests.

Content exploration for e-learning using XML Web services

Obtaining high quality content in an e-learning portal is critical to maximise the learning experience. For e-learning portals the content specialists are the publishers. Typically, publishers are nominated by portal administrators to make their content available to instructors. Instructors subsequently customise the portal by selecting content according to their requirements. The choice of content is limited to that provided by the publishers. This is a rigid system owing to the fact that instructors do not have access to an exhaustive range of content. We propose a system based on XML Web services which can be adopted by publishers in adherence with a number of emerging Web standards including SOAP and UDDI to disseminate their content. This system can be leveraged by portals to preview and subsequently acquire content which best suits the requirements as determined by instructors.

Interoperable and transparent dynamic deployment of web services for service oriented grids

Dynamic deployment of Web services is a term used frequently when describing the selection and deployment of a service to a grid host. Although current grid systems (such as Globus) provide dynamic deployment, the requirements of the service being deployed are not considered. Therefore truly dynamic deployment cannot be achieved as the services deployed are restricted to the grid system used. We present a dynamic deployment mechanism as part of self configuration in a service oriented grid environment. The dynamic deployment mechanism takes the requirements of the service into consideration, including parameters such as the operating system required to execute the service, the required software libraries, any additional required software packages, price and Quality of Service (QoS) parameters.

Protecting web services with service oriented traceback architecture

Service oriented architecture (SOA) is a way of reorganizing software infrastructure into a set of service abstracts. In the area of applying SOA to Web service security, there have been some well defined security dimensions. However, current Web security systems, like WS-Security are not efficient enough to handle distributed denial of service (DDoS) attacks. Our new approach, service oriented traceback architecture (SOTA), provides a framework to be able to identify the source of an attack. This is accomplished by deploying our defence system at distributed routers, in order to examine the incoming SOAP messages and place our own SOAP header. By this method, we can then use the new SOAP header information, to traceback through the network the source of the attack. According to our experimental performance evaluations, we find that SOTA is quite scaleable, simple and quite effective at identifying the source.

Protecting web services from distributed denial of service attacks

The outcome of the research was the development of three network defence systems to protect corporate network infrastructure. The results showed that these defences were able to detect and filter around 94% of the DDoS attack traffic within a matter of seconds.

Reliability of web services

This thesis explores the fault tolerance issues of web services computing and proposes a model for reliability of transaction-oriented web services applications.

Defending grid web services from XDoS attacks by SOTA

Grid Web Services are still relevantly a new to business systems, and as more systems are being attached to it, any threat to it could bring collapse and huge harm. Some of these potential threats to Grid Web services come in a new form of a new denial of service attack (DoS), called XML Denial of Service or XDOS attacks. Though, as yet, there have not been any reported attacks from the media, we have observed these attacks are actually far less complex to implement than any previous Denial of Service (DoS), but still just as affective. Current security applications for grid web services (WS-Security for example), based on our observations, and are not up to job of handling the problem. In this paper, we build on our previous work called Service Oriented Traceback Architecture (SOTA), and apply our model to Grid Networks that employ web services. We further introduce a filter defence system, called XDetector, to work in combination with SOTA. Our results show that SOTA in conjunction with XDetector makes for an effective defence against XDoS attacks and upcoming DXDoS.