| Architect: SOA Integration
SOA Integration in the Legacy Environment
by Tom Laszewski and Jason Williamson
Organizations with legacy applications don't have to throw the baby out with the bathwater when undertaking new initiatives.
Published October 2008
There is an increasing drive for organizations to move away from monolithic, static applications to Service-oriented Architecture (SOA) and the promise of agile, cost-effective, future-proof services. That is certainly the case among the many Fortune 500 companies with which the authors are involved in legacy modernization efforts. Monolithic systems form the core of nearly all of these companies.
But while services and the notions of agility and portability form the basis of our discussions of new application development initiatives with these organizations, legacy applications are the elephant in the room. What does SOA mean for organizations that have applications that are years, even decades old, applications that are maintained with a dwindling workforce and costly to change? These are issues that every IT manager must deal with.
The simple fact is that these monolithic systems are at the heart of banking, transportation, and manufacturing sectors around the world. But organizations do not have to throw the baby out with the bathwater when it comes to new initiatives. This article provides several examples that illustrate how Oracle technologies can be used to integrate legacy environments.
SOA in Context
The term SOA has been used, perhaps overused, to the point that it has lost its currency among decision makers. So before we dive into our use cases, let's take a moment to define what SOA means in terms of the legacy mainframe environment and legacy modernization.
Think of SOA as a framework for building applications, rather than as a specific set of technologies or protocols. SOA is a way of providing computing resources by exposing discrete business processes for use by consumers. More than a set of protocols and technologies—such as SOAP and WSDL or Java/RMI—SOA is a blueprint for building applications. Web services are one option for implementing this framework. Other technologies that can be leveraged to employ a service-oriented architecture include Business Activity Monitoring (BAM), Business Process Execution Language (BPEL), Enterprise Service Bus (ESB), and Business Process Management (BPM) engines. Technically, FTP is a SOA interface!
Integrating SOA into a Legacy Framework
The fundamental idea of enabling a legacy application starts with identifying the core building blocks and access points in the mainframe. There are three main points of integration into the legacy mainframe:
SOA Integration: Top Four Scenarios and Oracle Solutions
Technical journals and IT analysts have made the point that SOA is neither a product nor solution, but a journey. In that same sense, modernization is just such a journey, but one for which some additional packing is necessary, so to speak. This modernization journey will take unexpected twists and turns and visit unanticipated places as business objectives, key personnel, and technologies change.
The information presented here is based on factors and situations we have found to be common among the customers and partners we have assisted on their modernization journeys. The specifics of each situation and environment -- business drivers, strategic direction, tactical solutions under consideration, or biggest pain point ? may vary. But it is our hope that by the end of this section any questions about when, where, and how to start will have answered.
Oracle Products Included in the Solution
The Oracle Fusion Middleware family of products contains all the necessary components for a Service-Oriented Legacy Service Bus/SOA Integration architecture. But before we get started, let's cover why the selected products make the most sense, and explain why other products were omitted.
Why Web services?
Why Oracle Legacy Adapters?
Why Oracle BPEL Process Manager?
Oracle BPEL Process Manager allows SOA service implementations, human interaction, and system workflow to be orchestrated quickly and easily using graphical drag-and-drop techniques that allow direct user involvement in system orchestration, thereby reducing the amount of custom code required, and increasing application agility.
Why Oracle Enterprise Service Bus?
Oracle ESB provides a messaging and integration layer for directly connecting applications and web services through a common infrastructure. Oracle ESB combines an asynchronous messaging backbone with intelligent message transformation and routing to ensure that messages are passed reliably. The mainframe is known for its quality of service and reliability.
Oracle ESB makes use of Oracle Application Server's grid capabilities to allow the formation of an ESB grid that crosses multiple platforms.
Why Oracle Enterprise Manager (OEM)?
Why Oracle Identity Management?
Why Oracle WebCenter Portal?
Why Oracle Data Integrator?
Why Oracle Business Activity Monitoring (BAM)?
Why Oracle Business Intelligence?
Scenario One: Enterprise Information Integration
Also known as: Data Integration, file sharing, file messaging.
The current infrastructure for information integration is fragile, expensive, and difficult to maintain.
The problem is often characterized by issues with no common work-flow approach, a lack of data quality and data profiling capabilities, customized transformation logic unique to each data feed, lack of real time monitoring capability, and an inability to quickly add new data feeds.
Data needs to be shared with new systems developed on open systems and with other mainframe systems, both internal and external to the organization. Most legacy systems have incoming or outgoing data feeds.
Stand-alone applications and organizations are things of the past. The need now is for information-sharing between applications and businesses.
The solution includes Oracle ESB, Oracle BPEL, Oracle Legacy Adapters, Oracle E-Business Suite Adapters, and Oracle OEM, as depicted below:
Scenario One Summary
An important objective of Legacy SOA Integration is to avoid disruption of the current business processing and legacy system. This solution holds true to this objective by leaving the data feed unchanged.
Performing even minor changes to data feeds can be problematic:
The current data feed will remain intact, will download via FTP to a directory, and will most likely remain batched. This solution involves technologies such as Legacy Adapters and Oracle Messaging because they can be adapted when changes to business processes are made.
Common Error Processing
Data persistence Web service
Scenario Two: Web Enablement
Also known as: Screen Scraping, Re-interfacing.
Customer support people, sales representatives, customers, and partners would like to access the system through the Web. However, no single interface is available to allow updates to both the legacy system and the Oracle system.
Old green-screen technologies have many limitations, not the least of which is that they are not very intuitive. Access to several screen or systems is necessary in order to access essential information, and there is no point-and-click. In addition, users often have to go to multiple systems to either query or update the same or similar data.
Users want their data now, wherever they are, and at any time of the day or night. Users also want legacy systems and new Oracle environments to work together.
A business process that requires a user to query and then update multiple systems slows everything down, and in many cases may cause data inconsistencies.
Technologies that provide better application interfaces have been in the marketplace for years. But of even greater significance is the entry into the workforce of a generation of explicitly web-savvy users, and their ranks continue to grow.
This solution includes Oracle WebCenter, JSF/JSP, Oracle Legacy Adapters, and Oracle OEM, as depicted below:
Scenario Two: Summary
The key to this scenario is the interface. Therefore, Oracle WebCenter and/or JSP/JSF will be used. For the first iteration of this scenario, JSP and/or JSF can be used to simplify development and speed deployment. A more sophisticated alternative would use JSF to develop JSR-168 portlets, which would then be deployed using Oracle WebCenter.
Scenario Three: Report Off-Load Using Data Migration
Also known as: Data migration, Legacy Operational Data Store, Reporting Modernization.
IT Perspective: The legacy reporting infrastructure costs millions to run and has resulted in a six-month backlog of report requests.
User Perspective: Even with 100 green-bar reports there is insufficient information on which to make business decisions.
Users need access to information in a variety of formats and dimensions. They also need to be able to easily create ad hoc and what-if scenarios.
It is not uncommon for a mainframe-centric organization to rely solely on spreadsheets for strategic sales forecasting.
Generating reports on the mainframe is expensive, and places obstacles between business users and the information they need to make decisions. In a typical organization users will create their own reports using Excel, SQL, and other desktop tools, often resulting in duplicated data throughout the enterprise.
This solution includes Oracle Data Integrator, Oracle BPEL, Oracle Legacy Adapters, Oracle BAM, Oracle BI Suite and Oracle OEM.
Scenario Three Summary
This summary will explain the rationale behind the selection of Oracle products used in this scenario.
Oracle Data Integrator (ODI)
Scenario Four: End-to-End SOA
Also known as: Software as a Service (SaaS), Legacy SOA Integration.
This solution includes Oracle WebCenter, Oracle PBM, Oracle BPEL, Oracle Legacy Adapters, Oracle BAM, Oracle ESB, Oracle OID and SSO, and Oracle OEM.
Scenario Four Summary
As with the previous scenario, this summary will explain the rationale behind the selection of the Oracle products used in this scenario.
Oracle OID and SSO
SOA Integration: Final Summary
This article provides an overview of how a legacy environment can be integrated into current and future initiatives. The examples and techniques presented here represent only a few of the possibilities. The authors provide a more detailed, hands-on approach in the book Oracle Modernization Solutions (Packt Publishing, ISBN: 1847194648).
Jason Williamson, Product Manager of Modernization Solutions at Oracle, is part of the team responsible for developing and implementing Oracle's Modernization strategy, cultivating a partner ecosystem for implementing solutions that modernize to Oracle products. Jason works with Oracle product management and Oracle partners to drive integration, innovation and adoption for modernization to open systems.
Tom Laszewski is Technical Director of the Oracle Modernization Solutions team, where he works on a daily basis with EDS and HP alliances, technical architectures, and account managers to ensure the success of joint modernization projects. Tom is also responsible for Oracle Modernization customer assessments and workshops, modernization reference architectures and modernization best practices.