Towards restful web service composition for healthcare domain

The need for adaptability in software is growing, driven in part by the emergence of autonomic computing. In many cases, it is desirable to enhance existing programs with adaptive behavior, enabling them to execute effectively in dynamic environments. Existing web service invocation and adaptation mechanisms are limited only to the scope of web service choreography in terms of web service selection. 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. In this paper we used Aspect oriented programming (AOP) to invoke Web Services (WS) and Representational State Transfer (REST) web services and to enable dynamic adaptation in existing programs. We propose an approach to implement dynamic adaptability especially in Aspect weaving at the time invoking web services and REST web service. We have used AspectJ; Java based language to create aspects in Eclipse supported framework.

Internet is providing the platform for accessing different kinds of services in a distributed and heterogeneous environment. Software components are available on Internet in the form of Web Services. Service Oriented Architecture (SOA) possesses various characteristics by executing Web Services using Simple Object Access Protocol (SOAP). SOAP has certain limitations such as tightly coupled invocation, performance in terms of response data, non-uniform interface and no hyperlink support. These limitations can be resolved by implementing principles of Representational State Transformation (REST). REST is an architectural style implemented by resources known as RESTful Web Services. At present, light-weight RESTful services are dominating the development of services due to simplicity of RESTful architecture. Service access and invocation is simple in RESTful framework as it uses Uniform Resource Identifier (URIs) and Hyperlinks. In this paper, we explore the idea of RESTful Service Mashup by integrating individual Web Services which can satisfy end users' requirements. For this work, we propose a recursive algorithm. The implementation work is on Android 2.2 (froyo), API level 8 and above. It is supported on most of Android based mobile devices.

RESTful Web service composition with BPEL for REST

In today`s world of science & technology mobile device especially Smartphones plays the role of “"Jinn" who fulfill demand of the user. Smartphone through its Internet facility allows users to access various internet based web services ubiquitously to fulfill his/her demand. Web Services can be of two types SOAP or Restful services. Many researchers have mentioned that SOAP based services are heavy to consume on mobile device despite the fact that most of the companies still uses SOAP services but answer to this challenge is Restful Web Services. Restful services also surfers from many problems like processing of work or accessing services on device due to mobile phone`s small screen size, low processing power, less memory storage capacity etc. That`s why the heavy processing work is shifted on Cloud and only client part will be on mobile device, this integration is called as Mobile Cloud Computing (MCC). In MCC important point need to consider is to improve the performance of web services in terms of speed, memory usage and reducing latency. To resolve these issues, this paper has proposed MCC architecture. We have divided this paper is into two parts, in the first part; we did comparative analysis of Web Service consumption on mobile devices using cloud and various parameters used. In second part we have proposed architecture for mobile Web Services in Cloud which compress response data using Gzip and use of web caching to reduce overhead of repeated or previously accessed Web Service.

Representational State Transfer (REST). It’s all the rage these days. And, actually, has been for the last few years (at least). Even so, many developers are still trying to wrap their heads around what it actually means to build a RESTful service. No doubt if you’re developer, or anyway near development activities, you’ve had a run-in with designing, building, or fixing a REST service. It’s become one of those things that everyone wants to do, but not many know exactly why they should or shouldn’t. On top of that, there’s a wide variety of technologies out there for building RESTful services, many of which actually get in the way of understanding what REST is really about.

Security is not taken into account by default in the Representational State Transfer (REST) architecture, but its layered architecture provides many opportunities for implementing it. In this paper, a security mechanism for Web Service communication through mobile clients devices is proposed, that conforms to the REST architecture as much as possible. This approach has been inspired by some known security mechanisms, but implemented in such a way that it focusses on statelessness and aims to be lightweight. Results indicate that the custom security mechanism outperforms the Transport Layered Security (TLS) based system. Because of the genericness of REST, the proposed security mechanism can be adopted by a wide variety of other RESTful Web Services.

Representational State Transfer (REST) web services rapidly increased their importance in the last years. Nowadays a lot of services use this architectural style to benefit from the advantages and characteristics of a RESTful system. To call a web service REST compliant several constraints have to be fulfilled by software developers. The compliance of these guidelines is often not ensured even though many services call themselves RESTful. By applying Model Driven Software Development aspects to the design of REST applications a system was developed to decrease the effort which is needed to follow those constraints and reduce the time it takes to design and implement a REST web service. The process involves the modeling and editing of several abstract models which act as an input for a code generator that creates a JAX-RS web service. The models are defined by using the Eclipse Modeling Framework (EMF) with additions for graphical modeling. Since the current outcome of the existing prototype is not completely REST compliant certain improvements have to be made. This thesis reveals flaws during the modeling process in several meta models and in their transformations. It states enhancements how to improve and ease the process as well as increasing the quality and REST compliance of the generated outcome. To verifiy an improved state of the software a show case is used as a reference throughout the document. Finally the applied changes to the approach and the system structure are realized and demonstrated regarding this show case.

New value-added business, generated by Web service composition in BPEL, provides more powerful and flexible features. SOAP-based web services invoked in BPEL are heavy with redundant information and lower performance. RESTful Web service is brought forward to new value-added business as an alternative solution. However, it's a big challenge to compose RESTful Web services with SOAP-based Web Services in SOA BPEL business processes. BPEL is not designed to use RESTful Web services because these types of services do not use WSDL to describe themselves. This paper proposes a novel approach for integrating RESTful Web services and SOAP-based Web services in business processes described in BPEL. The approach is applied to a practical multimedia conference BPEL process, and the experimental data show the stability of the new RESTful BPEL process with a higher performance.

Service Oriented Architecture (SOA) introduced the web services as distributed computing components that can be independently deployed and invoked by other services or software to execute composite services that represent an end-to-end business process. An important problem in the SOA is the web service selection and composition problem which involves selecting the right web services mix to construct the best service composition that achieves the consumers Service Level Agreement (SLA) requirements. In this chapter we propose different methods to solve the problem of the business processes execution engine web service selection and services composition construction in the Service Oriented Architecture (SOA).  The chapter provides different mechanisms to improve the web services selection and composition using dynamic techniques. The main goal is to satisfy the services' requirements expressed as the SLA and to enhance the services selection and composition by increasing the availability and decreasing the response time of the service compositions.

The REpresentational State Transfer (REST) architectural style describes the design principles that made the World Wide Web scalable and the same principles can be applied in enterprise context to do loosely coupled and scalable application integration. In recent years, RESTful services are gaining traction in the industry and are commonly used as a simpler alternative to SOAP Web Services. However, one of the main drawbacks of RESTful services is the lack of standard mechanisms to support advanced quality-of-service requirements that are common to enterprises. Transaction processing is one of the essential features of enterprise information systems and several transaction models have been proposed in the past years to fulfill the gap of transaction processing in RESTful services. The goal of this paper is to analyze the state-of-the-art RESTful transaction models and identify the current challenges.

Distributed simulations are mainly used to interoperate heterogeneous simulators or geographically distributed models. We present here RESTful-CD++, the first distributed simulation middleware based on REST (Representational State Transfer) Web-services. RESTful-CD++ middleware enables heterogeneous independent-developed simulation components to intero-perate with much flexibility and simplicity. REST has the potential to advance distributed simulation state-of-the-art towards plug-and-play or automatic/semi-automatic interoperability. This because of its lightweight approach hides internal software implementation by using universal uniform interface and describing connectivity semantics in form of messages, usually XML. In contrast, other approaches expose functionalities in heterogeneous RPCs that often reflect internal implementation and describe semantics in form of procedure parameters. Further, REST enables simulations to mashup with Web 2.0 applications, which makes simulation in link with any device attached to the Web dynamically at runtime. The CD++ tool is now the first simulation engine to use RESTful middleware to perform distributed simulation in large-scale.

In this chapter, a high-level comparison of both SOAP (Simple Object Access Protocol) and REST (Representational State Transfer) is made. These are the two main approaches for interfacing to the web with web services. Both approaches are different and present some advantages and disadvantages for interfacing to web services: SOAP is conceptually more difficult (has a steeper learning curve) and more “heavy-weight” than REST, although it lacks of standards support for security. In order to test their efficiency (in time), three experiments have been performed using both technologies: first a basic client-server model implementation to test communications has been implemented; then, a master-slave based genetic algorithm (GA) to solve an optimization problem has been used; and finally, as third experiment, an approach to evolutionary distributed optimization of multilayer perceptrons (MLP) using REST and language Perl has been done. In these experiments, a master-slave based evolutionary algorithm (EA) has been implemented, where slave processes evaluate the costly fitness function (training a MLP to solve a classification problem). As expected, the parallel version of the developed programs obtains similar or better results using much less time than the sequential version, obtaining a good speedup. The results obtained have shown that both SOAP and REST can be used as communication protocol for distributed evolutionary computation, obtaining a good speedup. Results obtained are comparable, and only for large amounts of data (big messages), REST communications take longer than SOAP communications.KeywordsEvolutionary ComputationSimple Object Access ProtocolMaster ProcessOperator PriorityGood SpeedupThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Managing Service Level Agreement (SLA) for composite semantic web services is a very complex process, as it involves many complex tasks such as components discovery, provisioning, monitoring, recovery, and coordination. Indeed, managing all these tasks manually is a very cumbersome operation, nevertheless it is time consuming and prone to errors. To overcome such problems, automated SLA management for composite semantic web services is needed. This requires the SLA of the composite service to be described in a machine-understandable format such that it can be understood and processed by the automated SLA management tool. Currently, there is no SLA description language for composite semantic web services, but there exists an SLA description language for atomic web services, known as the Web Service Level Agreement (WSLA). Hence, in this paper, we aim to extend the WSLA language to describe composite semantic web services' SLAs, then we show how we can automatically generate the components' SLAs from the composite semantic web services' SLAs; adopting the CRECENT framework that we previously proposed for managing composite web services.

Aiming at the hot and difficult issues in Web services and service composition, this paper analyzes and studies the selection of Web services and service composition from the functional and non functional attributes of Web services, and mainly makes the following work and innovation. First of all, the functional attributes of Web services are studied, Web services on various service provision platforms are collected, and Web services are classified. Secondly, aiming at the shortcomings of existing Web service QoS attribute evaluation models, an improved method is proposed, which introduces a comprehensive evaluation mechanism of variable weight vector. Based on the constant weight comprehensive evaluation method, the state variable weight vector is established to dynamically adjust the attribute weights of various service QoS indicators, so as to improve the accuracy and objectivity of the Web service QoS attribute evaluation. Finally, in view of the defects and deficiencies of traditional algorithms in the selection of Web service composition, the particle swarm optimization algorithm with linearly decreasing inertia weight and learning factor is introduced, which better balances the self cognition and social learning ability of particles, and improves the search speed and global search ability of particles. And a large number of experiments are carried out to compare it with the traditional algorithm, which verifies the effectiveness and superiority of the improved particle swarm optimization algorithm.

Service-oriented architecture (SOA) is being increasingly used by developers both in web applications and in mobile applications. Within web services there are two main implementations: SOAP communication protocol and REST. This work presents a comparative study of performance between these two types of web services, SOAP versus REST, as well as analyses factors that may affect the efficiency of applications that are based on this architecture. In this experimental evaluation we used an application deployed in a Wildfly server and then used the JMeter test tool to launch requests in different numbers of threads and calls. Contrary to the more general idea that REST web services are significantly faster than SOAP, our results show that REST web services are 1% faster than SOAP. As this programming paradigm is increasingly used in a growing number of client and server applications, we conclude that the REST implementation is more efficient for systems which have to respond to less calls but have more requests in a connection.