Click here to close now.

Welcome!

Microservices Journal Authors: Pat Romanski, Srinivasan Sundara Rajan, Blue Box Blog, Elizabeth White, John Treadway

Related Topics: Microservices Journal

Microservices Journal: Article

Building SOA with Tuscany SCA

A simple service-oriented infrastructure

Many articles have already been written about service-oriented architecture (SOA) and Service Component Architecture (SCA), for example, see references [1] and [2]. In this article we'll focus on a freely available, open source implementation of the Service Component Architecture that provides a simple way to implement SOA solutions. This SCA implementation is being developed in the Apache Tuscany Incubator project. The project started in 2006 and is being used by many who are looking for a simple SOA infrastructure. The recent Tuscany SCA version 1.0, which was released in September 2007, supports the Service Component Architecture specifications 1.0. In addition to implementing the SCA specifications, Tuscany is also a nursery for new ideas. Some of these ideas will find their way into the specifications and some will be regarded as extensions available in Apache Tuscany Incubator. For example, support for Ruby, JavaScript, XQuery, data binding and Web 2.0 are currently extensions beyond the specification.

This article will walk you through what is available in Apache Tuscany Incubator and therefore highlight the benefits of SCA.

Using Tuscany SCA
A Common Approach to Application Construction and Deployment

Enterprise software development is increasingly influenced by technology choices, regulations, competition and expectations for responsiveness to change. Enterprises need the flexibility to adopt new business practices (like outsourcing of mortgage handling by a bank), enforce new regulations, and extend or down-size without much cost (mergers and acquisitions). In addition, as the complexity of the enterprise grows, a common management paradigm becomes a necessity for managing business applications. Service Component Architecture provides a simple programming model to address these challenges. SCA's simple language maps easily to the business. Let's consider we are building a banking application that handles account inquiries. Table 1 maps business-level questions to SCA.

SCA provides a consistent model of distributed applications and of the components from which they are constructed. This model explicitly separates business logic (Component/Services/References) from the details of how a running application is assembled (Composite/Wire) and deployed. This promotes a common terminology and supports a common understanding of the capability of applications and the way those applications work together. This common model also provides the hooks for tooling, governance, monitoring, and management in the service-oriented world.

When it comes to building a solution for real, one of the most important questions is likely to be "how can existing IT infrastructure and skills be used?" Tuscany SCA does not invent new technologies for component implementations (Implementation) and message exchange (Binding). It neither requires you to learn a new programming language nor communications protocols. You are free to leverage your existing investment in applications, technology, and skills as long as suitable support exists in Tuscany SCA. This is not much of a hurdle; Tuscany SCA has a straightforward extensibility model so new or proprietary technologies can easily be included.

The following sections describe Tuscany SCA in the context of three familiar scenarios. It should be noted that Tuscany SCA is not restricted to these scenarios. The sample code and configuration used here can be found in the Tuscany SCA Java distribution [3] and is available under the Apache License [4].

Enterprise Applications
In a typical enterprise, business functions are implemented using various technologies, business data is represented in different formats, and business applications communicate using heterogeneous protocols. It is almost impossible to converge all applications onto one technology stack such as Web services and so it remains difficult and costly to integrate different applications in an enterprise. Enterprises face many challenges including the following.

•  Business applications are tightly coupled with the IT infrastructure and early design decisions have to be made before real deployment.
•  Application developers are forced to learn and understand many technologies beyond business domain knowledge
•  Business logic is polluted and coupled to various technology-specific API calls imposed by the IT infrastructure. It's not easy to write and not easy to change.

SCA separates business services from the concerns related to specific hardware, software and network protocols by providing a unified programming model that allows the SCA runtime to handle these issues transparently. Let's look at a simple business scenario to see how Tuscany SCA can help enterprise application integration. The scenario here is the BigBank demo from the Tuscany SCA distribution [5]. As illustrated in Figure 1, the application comprises a number of assembled components and ultimately returns a total account balance in response to account inquires.

The use of the SCA programming model allows the BigBank developer to decouple the process of designing and creating the scenario from infrastructure concerns. In the BigBank composite, basic units of business logic are modelled as SCA components called AccountComponent, StockQuoteComponent, etc. Their business logic is implemented using Java and various scripting languages. Components are assembled by wiring references to services. Once all business logic is implemented, appropriate bindings are applied to references and services to indicate how the components should communicate.

The XML-based SCA configuration language describes all of the information about loosely coupled enterprise services and the bindings to be used. Since binding information can be changed in the SCA configuration without changing the business logic, the implementation code is not polluted with protocol handling information and, furthermore, bindings can be changed during deployment without impacting the application.

The following SCA configuration shows the AccountService exposed using JSONRPC (binding.jsonrpc) and Web services (binding.ws). The service can easily be made accessible over RMI by simply adding binding.rmi.

<component name="AccountServiceComponent">
    <implementation.java class="bigbank.account.AccountServiceImpl" />

    <service name="AccountService">
       <tuscany:binding.jsonrpc uri="/AccountJSONService" />
       <binding.ws
       wsdlElement="http://bigbank#wsdl.port(AccountService/AccountServiceSoap)" />
    </service>

    ...
</component>

The following SCA configuration shows bindings applied to component references. Again these bindings can be changed or augmented without changing the business logic.

<component name="AccountServiceComponent">
    ...
    <reference name="calculatorService">
       <tuscany:binding.rmi host="localhost" port="8099" serviceName="CalculatorRMIService" />
    </reference>

    <reference name="stockQuoteService">
       <binding.ws uri="http://localhost:8081/services/StockQuoteWebService" />
    </reference>
    ...
</component>

More Stories By Haleh Mahbod

Haleh Mahbod is a program director with IBM, managing the team contributing to the Apache Tuscany as well as SOA for PHP open source. She has extensive development experience with database technologies and integration servers.

More Stories By Raymond Feng

Raymond Feng is a senior software engineer with IBM. He is now working on the Service Component Architecture (SCA) runtime implementation in Apache Tuscany project as a committer. Raymond has been developing SOA for more than 4 years and he was a key developer and team lead for WebSphere Process Server products since 2002.

More Stories By Simon Laws

Simon Laws is a member of the IBM Open Source SOA project team working with the open source Apache and PHP communities to build Java, C++, and PHP implementations of the Service Component Architecture (SCA) and Service Data Object (SDO) specifications. Prior to this role he was working in the distributed computing space building service-oriented solutions for customers with a particular interest in grid computing and virtualization.

Comments (2) View Comments

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


Most Recent Comments
anonymous 03/12/08 06:13:08 PM EDT

SCA sounds a lot like CORBA..
or is it just me seeing this?

anonymous 11/11/07 09:28:46 PM EST

SCA = CORBA
CORBA = failure
SCA = ??

@MicroservicesExpo Stories
How do you securely enable access to your applications in AWS without exposing any attack surfaces? The answer is usually very complicated because application environments morph over time in response to growing requirements from your employee base, your partners and your customers. In his session at 16th Cloud Expo, Haseeb Budhani, CEO and Co-founder of Soha, will share five common approaches that DevOps teams follow to secure access to applications deployed in AWS, Azure, etc., and the frict...
The concept and subsequent adoption of 'Containerization'' is growing at a rapid speed with the support of almost every other major player in the industry. This concept is much more efficient than the Virtualization which has been a major option for Infrastructure optimization in the past decade. The following factors distinguish a Container from a Virtual Machine. Containers contain Only the Application Specific libraries and binaries. They do not include a guest operating system. Rather ...
SYS-CON Events announced today that Column Technologies, a global technology solutions company, will exhibit at SYS-CON's DevOps Summit 2015 New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Established in 1998, Column Technologies is a leader in application performance and infrastructure management for commercial and federal markets. The company is headquartered in the United States, with a diverse and talented team of more than 350 employees around th...
Financial services organizations were among the earliest enterprise adopters of cloud computing. The ability to leverage massive compute, storage and networking resources via RESTful APIs and automated tools like Chef and Puppet made it possible for their high-horsepower IT users to develop a whole new array of applications. Companies like Wells Fargo, Fidelity and BBVA are visible, vocal and engaged supporters of the OpenStack community, running production clouds for applications ranging from d...
Back in 2009 I posted about the “Great Cloud Shakeout” and the coming market consolidation into a few very large clouds. Nearly 5 1/2 years later and it’s about (long past?) time I took another look to see how I did. Back then I predicted that the market would be dominated by “mega CSPs” by the name of Amazon, Google and Microsoft. Note that this was during a period of Cambrian Explosion in the CSP market – it seems like everybody in the hosting business wanted to be a cloud provider....
As we recently previewed (read more about our London PoP in Jesse's post), Blue Box is opening a new Data Center in London, but hadn't announced the provider. Today we're excited to partner with TelecityGroup, whom we've selected as our data center partner in London. We chose their Powergate location, which is one of the U.K.'s most advanced, flexible and energy efficient carrier-neutral data centres. Why does that matter to you? Well, when customers choose Blue Box, they're trusting us with ...
Cloud Expo New York is happening from June 9 - 11. This event brings together the worlds of Cloud Computing, DevOps, IoT, WebRTC, Big Data and SDDC. We hope to see you there-members of the Blue Box team will exhibit in booth 218 next to the DevOps area. Plus, our Chief Product Officer, Hernan Alvarez, will present his talk "The Cloud Has a Down-and-Dirty Lining" as part of the Operations track in the DevOps Summit portion of the event on June 9 at 11 am. Learn more about his session her...
SYS-CON Events announced today Sematext Group, Inc., a Brooklyn-based Performance Monitoring and Log Management solution provider, will exhibit at SYS-CON's DevOps Summit 2015 New York, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Sematext is a globally distributed organization that builds innovative Cloud and On Premises solutions for performance monitoring, alerting and anomaly detection (SPM), log management and analytics (Logsene), search analytics (S...
SYS-CON Events announced today Isomorphic Software, the global leader in high-end, web-based business applications, will exhibit at SYS-CON's DevOps Summit 2015 New York, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Isomorphic Software is the global leader in high-end, web-based business applications. We develop, market, and support the SmartClient & Smart GWT HTML5/Ajax platform, combining the productivity and performance of traditional desktop software ...
SYS-CON Events announced today that Cisco, the worldwide leader in IT that transforms how people connect, communicate and collaborate, has been named “Gold Sponsor” of SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Cisco makes amazing things happen by connecting the unconnected. Cisco has shaped the future of the Internet by becoming the worldwide leader in transforming how people connect, communicate and collaborat...
We just finished the first O’Reilly Software Architecture Conference and the overwhelming most popular topic was microservices. Why all the hype about an architectural style? Microservices are the first post-DevOps revolution architecture. The DevOps revolution highlighted how much inadvertent friction an outdated operations mindset can cause, starting the move towards automating away manual tasks.
SYS-CON Media announced today that Blue Box as launched a popular blog feed on Cloud Computing Journal. Cloud Computing Journal aims to help open the eyes of Enterprise IT professionals to the economics and strategies that utility/cloud computing provides. Blue Box Cloud gives you unequaled agility, without the burden of designing, deploying and managing your own infrastructure. It’s the right choice when public cloud just won’t do. Blue Box Cloud is a managed Private Cloud as a Service (...
SYS-CON Events announced today that Ciqada will exhibit at SYS-CON's @ThingsExpo, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Ciqada™ makes it easy to connect your products to the Internet. By integrating key components - hardware, servers, dashboards, and mobile apps - into an easy-to-use, configurable system, your products can quickly and securely join the internet of things. With remote monitoring, control, and alert messaging capability, you will mee...
With the advent of micro-services, the application design paradigm has undergone a major shift. The days of developing monolithic applications are over. We are bringing in the principles (read SOA) hereto the preserve of applications or system integration space into the application development world. Since the micro-services are consumed within the application, the need of ESB is not there. There is no message transformation or mediations required. But service discovery and load balancing of ...
SYS-CON Events announced today that Open Data Centers (ODC), a carrier-neutral colocation provider, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Open Data Centers is a carrier-neutral data center operator in New Jersey and New York City offering alternative connectivity options for carriers, service providers and enterprise customers.
SYS-CON Events announced today that Akana, formerly SOA Software, has been named “Bronze Sponsor” of SYS-CON's 16th International Cloud Expo® New York, which will take place June 9-11, 2015, at the Javits Center in New York City, NY. Akana’s comprehensive suite of API Management, API Security, Integrated SOA Governance, and Cloud Integration solutions helps businesses accelerate digital transformation by securely extending their reach across multiple channels – mobile, cloud and Internet of Thi...
SYS-CON Events announced today that StorPool Storage will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. StorPool is distributed storage software that allows service providers, enterprises and other cloud builders to run data storage on standard x86 servers, instead of using expensive and inefficient storage arrays (SAN).
SYS-CON Events announced today that Soha will exhibit at SYS-CON's DevOps Summit New York, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Soha delivers enterprise-grade application security, on any device, as agile as the cloud. This turnkey, cloud-based service enables customers to solve secure application access and delivery challenges that traditional or virtualized network solutions cannot solve because they are too expensive, inflexible and operational...
Chef and Canonical announced a partnership to integrate and distribute Chef with Ubuntu. Canonical is integrating the Chef automation platform with Canonical's Machine-As-A-Service (MAAS), enabling users to automate the provisioning, configuration and deployment of bare metal compute resources in the data center. Canonical is packaging Chef 12 server in upcoming distributions of its Ubuntu open source operating system and will provide commercial support for Chef within its user base.
SYS-CON Events announced today that Site24x7, the cloud infrastructure monitoring service, will exhibit at SYS-CON's 16th International Cloud Expo®, which will take place on June 9-11, 2015, at the Javits Center in New York City, NY. Site24x7 is a cloud infrastructure monitoring service that helps monitor the uptime and performance of websites, online applications, servers, mobile websites and custom APIs. The monitoring is done from 50+ locations across the world and from various wireless carr...