Karthik Gomadam

hRESTS: An HTML Microformat for Describing RESTful Web Services

The Web 2.0 wave brings, among other aspects, the programmable Web: increasing numbers of Web sites provide machine-oriented APIs and Web services. However, most APIs are only described with text in HTML documents. The lack of machine-readable API descriptions affects the feasibility of tool support for developers who use these services. We propose a microformat called hRESTS (HTML for RESTful Services) for machine-readable descriptions of Web APIs, backed by a simple service model. The hRESTS microformat describes main aspects of services, such as operations, inputs and outputs. We also present two extensions of hRESTS: SA-REST, which captures the facets of public APIs important for mashup developers, and MicroWSMO, which provides support for semantic automation.

SA-REST: Semantically Interoperable and Easier-to-Use Services and Mashups

Services based on the representational state transfer (REST) paradigm, a lightweight implementation of a service-oriented architecture, have found even greater success than their heavyweight siblings, which are based on the Web Services Description Language (WSDL.) and SOAP. By using XML-based messaging, RESTful services can bring together discrete data from different services to create meaningful data sets; mashups such as these are extremely popular today.

An Online Platform for Web APIs and Service Mashups

On the newly programmable Web, mashups are flourishing. Designers create mashups by combining components of existing Web sites and applications. Although rapid mashup proliferation offers many opportunities, a lack of standarization and compatibility offers considerable challenges. IBM Sharable Code is an online service platform for developing and sharing situational Web 2.0 applications and mashups. The platform is based on an innovative domain-specific language that streamlines and standardizes the development and deployment of applications consuming and exposing Web APIs. Parts of the DSL and the resulting applications and mashups can be shared and reused by members of the IBM Sharable Code community. In this article, the authors offer an overview of the platforms architecture and the DSL language at its core.

SA-REST and (S)mashups : Adding Semantics to RESTful Services

The evolution of the Web 2.0 phenomenon has led to the increased adoption of the RESTful services paradigm. RESTful services often take the form of RSS/Atom feeds and AJAX based light weight services. The XML based messaging paradigm of RESTful services has made it possible to compose various services together. Such compositions of RESTful services is widely referred to as Mashups. In this paper, we outline the limitations in current approaches to creating mashups. We address these limitations by proposing a framework called as SA-REST. SA-REST adds semantics to RESTful services. Our proposed framework builds upon the original ideas in WSDL-S, our W3C submission, which was subsequently adapted for Semantic Annotation of WSDL (SAWSDL), now a W3C proposed recommendation. We demonstrate use of microformats for semantic annotation of RESTful services and then the use of such semanti- cally enabled services with better support for interoperability for creating dynamic mashups called SMashups.

Semantics to energize the full services spectrum

Using an ontological approach to better exploit services at the technical and business levels.

A Faceted Classification Based Approach to Search and Rank Web APIs

Web application hybrids, popularly known as mashups, are created by integrating services on the Web using their APIs. Support for finding an API is currently provided by generic search engines or domain specific solutions such as Google and ProgrammableWeb. Shortcomings of both these solutions in terms of and reliance on user tags make the task of identifying an API challenging. Since these APIs are described in HTML documents, it is essential to look beyond the boundaries of current approaches to Web service discovery that rely on formal descriptions. In this work, we present a faceted approach to searching and ranking Web APIs that takes into consideration attributes or facets of the APIs as found in their HTML descriptions. Our method adopts current research in document classification and faceted search and introduces the serviut score to rank APIs based on their utilization and popularity. We evaluate classification, search accuracy and ranking effectiveness using available APIs while contrasting our solution with existing ones.

Spatio-Temporal-Thematic Analysis of Citizen Sensor Data: Challenges and Experiences

We present work in the spatio-temporal-thematic analysis of citizen-sensor observations pertaining to real-world events. Using Twitter as a platform for obtaining crowd-sourced observations, we explore the interplay between the 3 dimensions in extracting insightful summaries of observations. We present our experiences in building a web mashup application, Twitris [1] that also facilitates the spatio-temporal-thematic exploration of social signals underlying events.

Optimal Adaptation in Web Processes with Coordination Constraints

We present methods for optimally adapting Web processes to exogenous events while preserving inter-service constraints that necessitate coordination. For example, in a supply chain process, orders placed by a manufacturer may get delayed in arriving. In response to this event, the manufacturer has the choice of either waiting out the delay or changing the supplier. Additionally, there may be compatibility constraints between the different orders, thereby introducing the problem of coordination between them if the manufacturer chooses to change the suppliers. We focus on formulating the decision making models of the managers, who must adapt to external events while satisfying the coordination constraints, using Markov decision processes. Our methods range from being centralized and globally optimal in their adaptation but not scalable, to decentralized that is suboptimal but scalable to multiple managers. We also develop a hybrid approach that improves on the performance of the decentralized approach with a minimal loss of optimality

A semantic template based designer for Web processes

The growing popularity of service oriented computing based on Web services standards is creating a need for paradigms to represent and design business processes. Significant work has been done in the representation aspects with regards to WSBPEL. However, design and modeling of business processes is still an open issue. In this paper, we present a novel designer for business processes, which allows for intuitive modeling of Web processes, as well as using a template based approach for semi-automatically integrating partners either at design time or at deployment time. This work has been done as part of the METEOR-S project, which concentrates on adding semantics to the entire Web process lifecycle.

A Semantic Framework for Identifying Events in a Service Oriented Architecture

We propose a semantic framework for automatically identifying events as a step towards developing an adaptive middleware for Service Oriented Architecture (SOA). Current related research focuses on adapting to events that violate certain non-functional objectives of the service requestor. Given the large of number of events that can happen during the execution of a service, identifying events that can impact the non-functional objectives of a service request is a key challenge. To address this problem we propose an approach that allows service requestors to create semantically rich service requirement descriptions, called semantic templates. We propose a formal model for expressing semantic templates and for measuring the relevance of an event to both the action being performed and the nonfunctional objectives. This model is extended to adjust the relevance of the events based on feedback from the underlying adaptation framework. We present an algorithm that utilizes multiple ontologies for identifying relevant events and present our evaluations that measure the efficiency of both the event identification and the subsequent adaptation scheme.