Aspect-Oriented Programming for Dynamic Web Service Monitoring and Selection

Abstract. In Service-Oriented Application Development, applications are composed by selecting and integrating third-party web services. To avoid hardwiring concrete services in client applications we introduced in previous work the Web Services Management Layer (WSML) and suggested a redirection mechanism based on Aspect Oriented Programming (AOP). Even though this mechanism enables hot swapping between semantically equivalent services based on their availability, this is not enough to create applications that are driven by business requirements. In this paper we introduce a more advanced selection mechanism that allows dynamic switching between services based on business driven requirements that can change over time. Choosing a service may be done based on cost, presence on approved partners list, as well as binding support, quality of service classifications, historical performance and proximity. We introduce a modular monitoring mechanism that is able to observe these criteria and trigger a more advanced service selection procedure. We show how the AOP language JAsCo with its dynamically pluggable aspects is well suited to achieve this. 1

Strengthening the security of cognitive packet networks

Route selection in cognitive packet networks (CPNs) occurs continuously for active flows and is driven by the users' choice of a quality of service (QoS) goal. Because routing occurs concurrently to packet forwarding, CPN flows are able to better deal with unexpected variations in network status, while still achieving the desired QoS. Random neural networks (RNNs) play a key role in CPN routing and are responsible to the next-hop decision making of CPN packets. By using reinforcement learning, RNNs' weights are continuously updated based on expected QoS goals and information that is collected by packets as they travel on the network experiencing the current network conditions. CPN's QoS performance had been extensively investigated for a variety of operating conditions. Its dynamic and self-adaptive properties make them suitable for withstanding availability attacks, such as those caused by worm propagation and denial-of-service attacks. However, security weaknesses related to confidentiality and integrity attacks have not been previously examined. Here, we look at related network security threats and propose mechanisms that could enhance the resilience of CPN to confidentiality, integrity and availability attacks