Aspect] is a simple and practical aspect-oriented extension to Java With just a few new constructs, AspectJ provides support for modular implementation of a range of crosscutting concerns. In AspectJ's dynamic join point model, join points are well-defined points in the execution of the program; pointcuts are collections of join points; advice are special method-like constructs that can be attached to pointcuts; and aspects are modular units of crosscutting implementation, comprising pointcuts, advice, and ordinary Java member declarations. AspectJ code is compiled into standard Java bytecode. Simple extensions to existing Java development environments make it possible to browse the crosscutting structure of aspects in the same kind of way as one browses the inheritance structure of classes. Several examples show that AspectJ is powerful, and that programs written using it are easy to understand.

An overview of AspectJ

http://emamispnu.persiangig.com/Projects/Cloud%20Computing/science_2.pdf

Review: A survey on security issues in service delivery models of cloud computing

The Object Management Group's (OMG) Model Driven Architecture (MDA) strategy envisages a world where models play a more direct role in software production, being amenable to manipulation and transformation by machine. Model Driven Engineering (MDE) is wider in scope than MDA. MDE combines process and analysis with architecture. This article sets out a framework for model driven engineering, which can be used as a point of reference for activity in this area. It proposes an organisation of the modelling 'space' and how to locate models in that space. It discusses different kinds of mappings between models. It explains why process and architecture are tightly connected. It discusses the importance and nature of tools. It identifies the need for defining families of languages and transformations, and for developing techniques for generating/configuring tools from such definitions. It concludes with a call to align metamodelling with formal language engineering techniques.

Model Driven Engineering

Recent technology trends in the Web Services (WS) domain indicate that a solution eliminating the presumed complexity of the WS-* standards may be in sight: advocates of REpresentational State Transfer (REST) have come to believe that their ideas explaining why the World Wide Web works are just as applicable to solve enterprise application integration problems and to simplify the plumbing required to build service-oriented architectures. In this paper we objectify the WS-* vs. REST debate by giving a quantitative technical comparison based on architectural principles and decisions. We show that the two approaches differ in the number of architectural decisions that must be made and in the number of available alternatives. This discrepancy between freedom-from-choice and freedom-of-choice explains the complexity difference perceived. However, we also show that there are significant differences in the consequences of certain decisions in terms of resulting development and maintenance costs. Our comparison helps technical decision makers to assess the two integration styles and technologies more objectively and select the one that best fits their needs: REST is well suited for basic, ad hoc integration scenarios, WS-* is more flexible and addresses advanced quality of service requirements commonly occurring in enterprise computing.

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Restful web services vs. "big"' web services: making the right architectural decision

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A survey on Internet of Things architectures

The service-oriented modeling and architecture modeling environment (SOMA-ME) is first a framework for the model-driven design of service-oriented architecture (SOA) solutions using the service-oriented modeling and architecture (SOMA) method. In SOMA-ME, Unified Modeling Language (UML™) profiles extend the UML 2.0 metamodel to domain-specific concepts. SOMA-ME is also a tool that extends the IBM Rational® Software Architect product to provide a development environment and automation features for designing SOA solutions in a systematic and model-driven fashion. Extensibility, traceability, variation-oriented design, and automatic generation of technical documentation and code artifacts are shown to be some of the properties of the SOMA-ME tool.

SOMA-ME: a platform for the model-driven design of SOA solutions

Service Oriented Architecture (SOA) has gained popularity as a design paradigm for realizing enterprise software systems through abstract units of functionality called services While the key design principles of SOA have been discussed at length in the literature, much of the work is prescriptive in nature and do not explain how adherence to these principles can be quantitatively measured in practice In some cases, metrics for a limited subset of SOA quality attributes have been proposed, but many of these measures have not been empirically validated on real-life SOA designs In this paper, we take a deeper look at how the key SOA quality attributes of service cohesion, coupling, reusability, composability and granularity may be evaluated, based only on service design level information We survey related work, adapt some of the well-known software design metrics to the SOA context and propose new measures where needed These measures adhere to mathematical properties that characterize the quality attributes We study their applicability on two real-life SOA design models from the insurance industry using a metrics computation tool integrated with an Eclipse-based service design environment We believe that availability of these measures during SOA design will aid early detection of design flaws, allow different design options and trade-offs to be considered and support planning for development, testing and governance of the services

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Measuring the Quality of Service Oriented Design

Existing web service composition and adaptation mechanisms are limited only to the scope of web service choreography in terms of web service selection/invocation vis-a-vis pre-specified Service Level Agreement constraints. Such a scope hardly leaves ground for a participating service in a choreographed flow to re-adjust itself in terms of changed non functional expectations and most often these services are discarded and new services discovered to get inducted into the flow. In this paper, we extend this idea by focusing on run-time adaptation of non-functional features of a composite Web service by modifying the non-functional features of its component Web services. We use aspect-oriented programming (AOP) technology for specifying and relating non-functional properties of the Web services as aspects at both levels of component and composite. This is done via a specification language for representing non-functional properties, and a formally specifiable relation function between the aspects of the component Web services and those of the composite Web service. From the end users' viewpoint, such upfront aspect-oriented modeling of non-functional properties enables on-demand composite Web service adaptation with minimal disruption in quality of service. We demonstrate the applicability and merits of our approach via an implementation of a simple yet real-life example.

/pdf/run-time-adaptation-of-non-functional-properties-of-1g0h6ejlb6.pdf

Run-Time Adaptation of Non-functional Properties of Composite Web Services Using Aspect-Oriented Programming

According to one embodiment of the present invention, a method computing resources are dynamically provisioned to meet service level objectives in a cloud computing environment. Resources available for provisioning to the cloud computing environment are determined and the quality thereof monitored. Current resource needs for a cloud job tenancy are determined, and selected resources are dynamically provisioned from resources available for provisioning based on the current resource needs and the quality of the resources available in order to meet the cloud job tenancy and the service level objectives.

Predictive and dynamic resource provisioning with tenancy matching of health metrics in cloud systems

A web service request is received by an intermediary that performs a conversion of the requestor's service interface to the service interface supported by a service provider matching the requested service, then invokes that service. A reverse conversion is performed when passing a reply to the requester. The web serving intermediary maintains a library of each target service in terms of the target service's tModel and on its binding protocol support. The intermediary receives web service requests from requestors including their source tModel and target web service information. The intermediary identifies a mapping aspect to invoke the target web service from the aspect library. The target service tModel is embodied in the mapping aspect which is weaved into the code invoking the target service at runtime. In this way, the interface logic is decided at run time.

Karthikeyan Ponnalagu

Papers

SOMA-ME: a platform for the model-driven design of SOA solutions

Measuring the Quality of Service Oriented Design

Run-Time Adaptation of Non-functional Properties of Composite Web Services Using Aspect-Oriented Programming

Predictive and dynamic resource provisioning with tenancy matching of health metrics in cloud systems

Aspect oriented web service invocation