Janaka Balasooriya

Service-Oriented Cloud Computing Architecture

Cloud computing is getting popular and IT giants such as Google, Amazon, Microsoft, IBM have started their cloud computing infrastructure. However, current cloud implementations are often isolated from other cloud implementations. This paper gives an overview survey of current cloud computing architectures, discusses issues that current cloud computing implementations have and proposes a Service-Oriented Cloud Computing Architecture (SOCCA) so that clouds can interoperate with each other. Furthermore, the SOCCA also proposes high level designs to better support multi-tenancy feature of cloud computing.

An Approach for Service Composition and Testing for Cloud Computing

As cloud services proliferate, it becomes difficult to facilitate service composition and testing in clouds. In traditional service-oriented computing, service composition and testing are carried out independently. This paper proposes a new approach to manage services on the cloud so that it can facilitate service composition and testing. The paper uses service implementation selection to facilitate service composition similar to Google’s Guice and Spring tools, and apply the group testing technique to identify the oracle, and use the established oracle to perform continuous testing for new services or compositions. The paper extends the existing concept of template based service composition and focus on testing the same workflow of service composition. In addition, all these testing processes can be executed in parallel, and the paper illustrates how to apply service-level MapReduce technique to accelerate the testing process.

SyD: a middleware testbed for collaborative applications over small heterogeneous devices and data stores

Developing a collaborative application running on a collection of heterogeneous, possibly mobile, devices, each potentially hosting data stores, using existing middleware technologies such as JXTA, BREW, compact .NET and J2ME requires too many ad-hoc techniques as well as cumbersome and time-consuming programming. Our System on Mobile Devices (SyD) middleware, on the other hand, has a modular architecture that makes such application development very systematic and streamlined. The architecture supports transactions over mobile data stores, with a range of remote group invocation options and embedded interdependencies among such data store objects. The architecture further provides a persistent uniform object view, group transaction with Quality of Service (QoS) specifications, and XML vocabulary for inter-device communication. This paper presents the basic SyD concepts and introduces the architecture and the design of the SyD middleware and its components. We also provide guidelines for SyD application development and deployment process. We include the basic performance figures of SyD components and a few SyD applications on Personal Digital Assistant (PDA) platforms. We believe that SyD is the first comprehensive working prototype of its kind, with a small code footprint of 112 KB with 76 KB being device-resident, and has a good potential for incorporating many ideas for performance extensions, scalability, QoS, workflows and security.

Fundamental Capabilities of Web Coordination Bonds: Modeling Petri Nets and Expressing Workflow and Communication Patterns over Web Services

Developing collaborative applications over the Web has become increasingly important. In order to accomplish this, Web services need to be extended beyond the basic service architecture (invoke and respond) to self-coordinating Web processes collaborating among themselves (transient to long lasting). A core set of artifacts is needed to allow these Web processes to hook together in a desired structure to enforce automatic information flow, group constraints, and data/control dependencies. We have proposed Web Coordination Bonds as such a set of artifacts with the required theoretical underpinning for effective collaboration among Web services. Here, we establish that Web bonds are at least as powerful as the extended Petri nets (modeling power). We demonstrate their expressiveness by modeling a comprehensive set of benchmark workflow scenarios and distributed communication patterns. Such fundamental treatments are unique, and are essential for further progress in the technology for distributed software over Internet.

Web coordination bonds: a simple enhancement to Web services infrastructure for effective collaboration

The Web services need to extend beyond the basic service architecture (invoke and respond) to self-coordinating Web processes collaborating among themselves in the desired configuration as per users application (transient to long lasting). A core set of artifacts are needed to allow these Web processes to hook together in a desired structure to enforce automatic information flow, group constraint satisfaction, and data and control dependencies, all without any central coordinating authority. We propose Web coordination bonds, analogous to the chemical bonds, as a set of such core artifacts for effective collaboration among Web services. There are two types of Web bonds: subscription bonds allow information, control and event flows whereas negotiation bonds enforce dependencies and contracts. Web bonds are simple yet powerful, and we demonstrate how they can be employed to create (model) and enforce (deploy and execute) producer-consumer and shared-resource relationships, workflow scenarios, and atomic transactions. We have developed and prototyped a middleware called system on devices (SyD) incorporating Web bonds, and have employed it to prototype a few distributed applications which bond existing Web services together to collaborate. Much remains to be done, including theoretical treatment of Web coordination bonds.

A Middleware Architecture for Enhancing Web Services Infrastructure for Distributed Coordination of Workflows

This paper discusses a layered workflow software architecture for distributed coordination of workflows over Web services and proposes fundamental enhancements to the web services infrastructure that facilitate the layered workflow software architecture. We verify our layered approach using a detailed simulation and a proof-of-concept prototype implementation. Our proposed architecture for Web service coordination management middleware (WSCMM) is a simple but powerful enhancement to the web service infrastructure enabling the services to locally manage their dependencies and to handle messages resulting from multiple workflows. We have carried out a detailed simulation to identify key components of our middleware architecture. We also compare and contrast our architecture with the current web service technologies. Our experiments demonstrate that we can develop both centralized and distributed workflows over the architecturally enhanced web services with relative simplicity. In addition, our lightweight coordination components with footprint no larger than 150 KB allow these workflows to be executed even on a handheld.

Ontology-based Information Sharing in Service-Oriented Database Systems

This paper presents a novel information sharing framework using Service-Oriented Database System (SODB) for service registry and repository that facilitates data integration. A SODB is a database architecture composed with reusable services to support searching, querying, deleting, and storing data. As SODB is organized in a service-oriented manner, SODB can be easily changed or maintained by reusing different services. Thus, it can be used to share information in the cloud. The Information Sharing System (ISS) component of the SODB employs domain ontology to share data sources. The domain ontology utilizes mathematical equivalence relations to map data sources into appropriate domain ontology. It also facilitates dynamic query composition across data sources. This paper also presents the design, implementation, and performance evaluation of the ISS component. Our implementation is based on a real application, the Arizona Healthcare Cost Containment System (AHCCCS). This application demonstrates that the ISS can facilitate complex information integration. Finally, this paper presents the performance of the ISS using WAPT (Web Application Testing) for Microsoft Windows XP, and the response time consistently fall in between 0.1 to 0.15 second for each request.

Distributed coordination of workflows over web services and their handheld-based execution

The current state of the art of workflow composition over web services employ a centralized composite process to coordinate the constituent web services. Therefore, the coordinator process is complex, less scalable, and bulky. This paper introduces an architecture and associated techniques for distributed coordination of these workflows, and a prototype system, namely BondFlow system, with capability to control workflow execution using a handheld device. We distribute the centralized coordination logic of traditional workflows by (i) extending the stateless web services into self-coordinating entities using coordinator proxy objects, and (ii) creating the workflow over these entities by interconnecting them into a distributed network of objects using web bond primitives. Previously, we have developed web bond primitives to enforce interdependencies among autonomous entities. The prototypedr BondFlow systeh provides a platform to configure such distributed workflows, producing coordination components with a footprint small enough to be executed on a handheld (footprint no larger than 150 KB).

A methodology for engineering collaborative applications over mobile Web objects using SyD middleware

Future Web applications will be more collaborative and will use the standard and ubiquitous Internet protocols. We have previously developed system on mobile devices (SyD) middleware to rapidly develop and deploy collaborative applications over heterogeneous and possibly mobile devices hosting web objects. In this paper, we present the software engineering methodology for developing SyD-enabled Web applications and illustrate it through a case study on a system of calendar application, with implementation on iPAQs and its performance metrics study. SyD-enabled Web objects allow us to create a collaborative application rapidly with limited coding. In this case study, the modular software architecture allowed us to hide the inherent heterogeneity among devices, data stores, and networks by presenting a uniform and persistent object view of mobile calendar objects interacting through XML/SOAP requests and responses. The performance results we obtained show that the application scales well as we increase the group size and adapts well within the constraints of mobile devices.

Development of NeuronBank: A Federation of Customizable Knowledge Bases of Neuronal Circuitry

Knowledge of neuronal circuitry is foundational to the neurosciences, but no tools have been developed for cataloguing this knowledge. Part of the problem is that the concepts used to describe neural circuits are rapidly evolving and vary substantially across different species. The NeuronBank project (http://neuronbank.org) is developing an informatics infrastructure for managing the dynamic, domain-specific knowledge of neural circuitry, providing a reference source, an outlet for publishing new knowledge, and a useful research tool. Our solution is a federation of customizable knowledge bases, each adaptable to store knowledge of the neural circuitry of a single species. The federation is united by a common set of web services and a central portal that provides core functionality across various knowledge bases. This service-oriented architecture provides domain-specific representations of specialized scientific knowledge while maintaining interoperability across a broad discipline.