Click here to close now.




















Welcome!

Microservices Expo Authors: Liz McMillan, Elizabeth White, Pat Romanski, Trevor Parsons, SmartBear Blog

Related Topics: Microservices Expo

Microservices Expo: 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
In his session at 17th Cloud Expo, Ernest Mueller, Product Manager at Idera, will explain the best practices and lessons learned for tracking and optimizing costs while delivering a cloud-hosted service. He will describe a DevOps approach where the applications and systems work together to track usage, model costs in a granular fashion, and make smart decisions at runtime to minimize costs. The trickier parts covered include triggering off the right metrics; balancing resilience and redundancy ...
SYS-CON Events announced today that G2G3 will exhibit at SYS-CON's @DevOpsSummit Silicon Valley, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Based on a collective appreciation for user experience, design, and technology, G2G3 is uniquely qualified and motivated to redefine how organizations and people engage in an increasingly digital world.
SYS-CON Events announced today that HPM Networks will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. For 20 years, HPM Networks has been integrating technology solutions that solve complex business challenges. HPM Networks has designed solutions for both SMB and enterprise customers throughout the San Francisco Bay Area.
Whether you like it or not, DevOps is on track for a remarkable alliance with security. The SEC didn’t approve the merger. And your boss hasn’t heard anything about it. Yet, this unruly triumvirate will soon dominate and deliver DevSecOps faster, cheaper, better, and on an unprecedented scale. In his session at DevOps Summit, Frank Bunger, VP of Customer Success at ScriptRock, will discuss how this cathartic moment will propel the DevOps movement from such stuff as dreams are made on to a prac...
SYS-CON Events announced today that Pythian, a global IT services company specializing in helping companies leverage disruptive technologies to optimize revenue-generating systems, has been named “Bronze Sponsor” of SYS-CON's 17th Cloud Expo, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. Founded in 1997, Pythian is a global IT services company that helps companies compete by adopting disruptive technologies such as cloud, Big Data, advance...
The pricing of tools or licenses for log aggregation can have a significant effect on organizational culture and the collaboration between Dev and Ops teams. Modern tools for log aggregation (of which Logentries is one example) can be hugely enabling for DevOps approaches to building and operating business-critical software systems. However, the pricing of an aggregated logging solution can affect the adoption of modern logging techniques, as well as organizational capabilities and cross-team ...
Culture is the most important ingredient of DevOps. The challenge for most organizations is defining and communicating a vision of beneficial DevOps culture for their organizations, and then facilitating the changes needed to achieve that. Often this comes down to an ability to provide true leadership. As a CIO, are your direct reports IT managers or are they IT leaders? The hard truth is that many IT managers have risen through the ranks based on their technical skills, not their leadership ab...
In today's digital world, change is the one constant. Disruptive innovations like cloud, mobility, social media, and the Internet of Things have reshaped the market and set new standards in customer expectations. To remain competitive, businesses must tap the potential of emerging technologies and markets through the rapid release of new products and services. However, the rigid and siloed structures of traditional IT platforms and processes are slowing them down – resulting in lengthy delivery ...
Several years ago, I was a developer in a travel reservation aggregator. Our mission was to pull flight and hotel data from a bunch of cryptic reservation platforms, and provide it to other companies via an API library - for a fee. That was before companies like Expedia standardized such things. We started with simple methods like getFlightLeg() or addPassengerName(), each performing a small, well-understood function. But our customers wanted bigger, more encompassing services that would "do ...
Docker containerization is increasingly being used in production environments. How can these environments best be monitored? Monitoring Docker containers as if they are lightweight virtual machines (i.e., monitoring the host from within the container), with all the common metrics that can be captured from an operating system, is an insufficient approach. Docker containers can’t be treated as lightweight virtual machines; they must be treated as what they are: isolated processes running on hosts....
SYS-CON Events announced today the Containers & Microservices Bootcamp, being held November 3-4, 2015, in conjunction with 17th Cloud Expo, @ThingsExpo, and @DevOpsSummit at the Santa Clara Convention Center in Santa Clara, CA. This is your chance to get started with the latest technology in the industry. Combined with real-world scenarios and use cases, the Containers and Microservices Bootcamp, led by Janakiram MSV, a Microsoft Regional Director, will include presentations as well as hands-on...
DevOps has traditionally played important roles in development and IT operations, but the practice is quickly becoming core to other business functions such as customer success, business intelligence, and marketing analytics. Modern marketers today are driven by data and rely on many different analytics tools. They need DevOps engineers in general and server log data specifically to do their jobs well. Here’s why: Server log files contain the only data that is completely full and accurate in th...
Skeuomorphism usually means retaining existing design cues in something new that doesn’t actually need them. However, the concept of skeuomorphism can be thought of as relating more broadly to applying existing patterns to new technologies that, in fact, cry out for new approaches. In his session at DevOps Summit, Gordon Haff, Senior Cloud Strategy Marketing and Evangelism Manager at Red Hat, discussed why containers should be paired with new architectural practices such as microservices rathe...
Any Ops team trying to support a company in today’s cloud-connected world knows that a new way of thinking is required – one just as dramatic than the shift from Ops to DevOps. The diversity of modern operations requires teams to focus their impact on breadth vs. depth. In his session at DevOps Summit, Adam Serediuk, Director of Operations at xMatters, Inc., will discuss the strategic requirements of evolving from Ops to DevOps, and why modern Operations has begun leveraging the “NoOps” approa...
Puppet Labs has announced the next major update to its flagship product: Puppet Enterprise 2015.2. This release includes new features providing DevOps teams with clarity, simplicity and additional management capabilities, including an all-new user interface, an interactive graph for visualizing infrastructure code, a new unified agent and broader infrastructure support.
Early in my DevOps Journey, I was introduced to a book of great significance circulating within the Web Operations industry titled The Phoenix Project. (You can read our review of Gene’s book, if interested.) Written as a novel and loosely based on many of the same principles explored in The Goal, this book has been read and referenced by many who have adopted DevOps into their continuous improvement and software delivery processes around the world. As I began planning my travel schedule last...
SYS-CON Events announced today that DataClear Inc. will exhibit at the 17th International Cloud Expo®, which will take place on November 3–5, 2015, at the Santa Clara Convention Center in Santa Clara, CA. The DataClear ‘BlackBox’ is the only solution that moves your PC, browsing and data out of the United States and away from prying (and spying) eyes. Its solution automatically builds you a clean, on-demand, virus free, new virtual cloud based PC outside of the United States, and wipes it clean...
It’s been proven time and time again that in tech, diversity drives greater innovation, better team productivity and greater profits and market share. So what can we do in our DevOps teams to embrace diversity and help transform the culture of development and operations into a true “DevOps” team? In her session at DevOps Summit, Stefana Muller, Director, Product Management – Continuous Delivery at CA Technologies, answered that question citing examples, showing how to create opportunities for ...
What does “big enough” mean? It’s sometimes useful to argue by reductio ad absurdum. Hello, world doesn’t need to be broken down into smaller services. At the other extreme, building a monolithic enterprise resource planning (ERP) system is just asking for trouble: it’s too big, and it needs to be decomposed.
The Microservices architectural pattern promises increased DevOps agility and can help enable continuous delivery of software. This session is for developers who are transforming existing applications to cloud-native applications, or creating new microservices style applications. In his session at DevOps Summit, Jim Bugwadia, CEO of Nirmata, will introduce best practices, patterns, challenges, and solutions for the development and operations of microservices style applications. He will discuss ...