Mashup editors, like Yahoo Pipes and IBM Lotus Mashup Maker, allow non-programmer end-users to ldquomash-uprdquo information sources and services to meet their information needs. However, with the increasing number of services, information sources and complex operations like filtering and joining, even an easy to use editor is not sufficient. MashupAdvisor aims to assist mashup creators to build higher quality mashups in less time. Based on the current state of a mashup, the MashupAdvisor quietly suggests outputs (goals) that the user might want to include in the final mashup. MashupAdvisor exploits a repository of mashups to estimate the popularity of specific outputs, and makes suggestions using the conditional probability that an output will be included, given the current state of the mashup. When a suggestion is accepted, MashupAdvisor uses a semantic matching algorithm and a metric planner to modify the mashup to produce the suggested output. Our prototype was implemented on top of IBM Lotus MashupMaker and our initial results show that it is effective.

Automatically finding suitable Web services given a request is a difficult problem because the interface descriptions of Web services are often terse and cryptic. Dictionary and information retrieval based techniques have proven useful in disambiguating the semantics of service descriptions, but they are limited in their capability to consider the relationships between the words describing the Web services. Current ontology-based approaches typically require a user to explicitly create domain ontologies. This paper presents a novel technique that significantly improves the quality of semantic Web service matching by (1) automatically generating ontologies based on Web service descriptions and (2) using these ontologies to guide the mapping between Web services. Our approach differs from earlier work on service matching by considering the relationship between words rather than treating them as a bag of unrelated words. The experimental results indicate that with our unsupervised approach we can eliminate up to 70% of incorrect matches that are made by dictionary-based approaches.

This paper presents a novel technique that significantly improves the quality of semantic Web service matching by (1) automatically generating ontologies based on Web service descriptions and (2) using these ontologies to guide the mapping between Web services.

In this paper, we present a novel algorithm to compose Web services in the presence of semantic ambiguity by combining semantic matching and AI planning algorithms. Specifically, we use cues from domain-independent and domain-specific ontologies to compute an overall semantic similarity score between ambiguous terms. This semantic similarity score is used by AI planning algorithms to guide the searching process when composing services. Experimental results indicate that planning with semantic matching produces better results than planning or semantic matching alone. The solution is suitable for semi-automated composition tools or directory browsers

In this paper, we explore the use of domain-independent and domain-specific ontologies to find matching service descriptions. The domain-independent relationships are derived using an English thesaurus after tokenization and part-of-speech tagging. The domain-specific ontological similarity is derived by an inference on the semantic annotations associated with Web service descriptions. Matches due to the two cues are combined to determine an overall semantic similarity score. By combining multiple cues, we show that better relevancy results can be obtained for service matches from a large repository, than could be obtained using any one cue alone.

Summary form only given. An increasing number of distributed applications are currently being constructed as sets of connected components and dynamically deployed in wide area networks using frameworks such as CORBA, .NET, and Web Services. Such dynamic deployments enable applications to flexibly adapt to changes in client QoS requirements and network properties, but introduce a consistency problem because of replicated components. Ideally, the frameworks deploying the applications should ensure that the application consistency requirements are satisfied, even though the requirements can range from weak to strong and dynamically change at run-time. Thus, a key challenge is to design a flexible cache coherence protocol that uses application-specific information while still being application-neutral. We describe Flecc, an application-neutral cache coherence protocol used by a component-based framework (Partitionable Services Framework) to satisfy the consistency requirements of deployed applications. Flecc allows applications to specify appropriate consistency and granularity levels and define complex synchronization decisions as simple functions. We demonstrate the benefits of our cache coherence protocol by analyzing the behavior of a component-based application modeling an airline reservation system.

Increasingly, scalable distributed applications are being constructed by integrating reusable components spanning multiple administrative domains. Dynamic composition and deployment of such applications enables flexible QoS-aware adaptation to changing client and network characteristics. However, dynamic deployment across multiple administrative domains needs to perform cross-domain authentication and authorization, and satisfy various network and application-level constraints that may only be expressed in terms meaningful within a particular domain. Our solution to these problems, developed as part of the partitionable services framework, integrates a decentralized trust management and access control system (dRBAC) with a programming and run-time abstraction (object views). dRBAC encodes statements within and across domains using cryptographically signed credentials, providing a unifying and powerful mechanism for cross-domain authorization and expression of network and application constraints. Views define multiple implementations of a reusable component, thus enriching the set of components available for dynamic deployment and enabling fine-grained, customizable access control. We describe the runtime support for views, which consists of a view generator (VIG) and a host-level communication resource (Switchboard) for creating secure channels between pairs of components. We present a simple mail application to illustrate how dRBAC, views, and Switchboard can be used to customize reusable components and securely deploy them in heterogeneous environments.

Several recently proposed infrastructures permit client applications to interact with distributed network-accessible services by simply "plugging in" into a substrate that provides essential functionality, such as naming, discovery, and multi-protocol binding. However much work remains before the interaction can be considered truly seamless in the sense of adapting to the characteristics of the heterogeneous environments in which clients and services operate. This paper describes a novel approach for addressing this shortcoming: the partitionable services framework, which enables services to be flexibly assembled from multiple components, and facilitates transparent migration and replication of these components at locations closer to the client while still appearing as a single monolithic service. The framework consists of three pieces: (1) declarative specification of services in terms of constituent components; (2) run-time support for dynamic component deployment; and (3) planning policies, which steer the deployment to accomodate underlying environment characteristics. We demonstrate the salient features of the framework and highlight its usability and performance benefits with a case study involving a security-sensitive mail service.