Developing with an Enterprise Service Bus

1. Developing with an Enterprise Service Bus Brian Cochran & Eric Stevens

2. Who We Are • Own and Operate Architecture Consulting Company specializing in ESB technology and implementations. • Working on an ESB implementation in the utility industry for last 18 months. • Expertise in extremely high volume transactional environments. Making use of ESB as a Grid enabler. • Background in architecting financial service and insurance solutions for Fortune 1000. • Primarily open source centric.

3. Outline • What is an ESB? • Where and why should you use one? • What tools should you use? • What do you need to do (a look at the popular Loan Broker example)? • What are the “gotchas”? • Who is using this stuff?

4. Software Agility Agility Customizations Renovation Roadmap Green Field

5. SOA Background What is a Service Oriented Architecture? • Loosely Coupled Business Services • Cross Platform • Distributed Environment Quoting App Submission Credit Inquiry Presentation Tier Not Just Business Tier Data Tier

6. Defining ESB • A Framework that helps in implementing Service Oriented Architectures • Can be used for other things • SOA does not require an ESB • Provides framework for • Messaging • Transformation • Routing • Orchestration NQuote NRate JCredit J2Quote

7. Applications of an ESB • Rapid Integration of different systems • Reuse of existing applications • Parallel Grid based Applications • To force decoupling of components • Build Asynchronous Applications

8. Lending Twig Loan Broker(adapted from the EIP book) I need a simple loan quoting site for Bank Fred ASAP! Yeah right, you’ve never done anything simple in your life.

9. Lending Twig Loan Broker Hibernate public class LoanBrokerImpl implements LoanBroker { // injected dependencies CreditAgencyService creditAgency = null; BankServiceFacade bankFacade = null;  // service method pulic LoanQuote createQuote(QuoteRequest req){ CreditReport cr =creditAgency.createCreditReport( req.getSSN()); LoanQuote lq = bankFacade.createQuote(req.getSSN(), req.getAmount(),cr);  return lq;} } Spring JSF Struts

10. Service Enabling Lending Twig Our partner wants to call our software as a Web Service and is talking about SOA things. Do we do that? I can see where this is going. Everyone is going to want to communicate with our software in different ways and use it in ways we never intended.

11. Finding an ESB Well I certainly don’t want to expose the Integration technology to my POJOs. And I’m betting That WS isn’t going to be the only way people try to integrate with this stuff. Let me look at using an ESB. Celtix TIBCO Mule Cape Clear Service Mix

12. Mule ESB • Light Weight and Embeddable • Supports POJO Components • Based on “Enterprise Integration Patterns” • Support for over 20 different protocols • Support for Pluggable Component Containers (Spring, JNDI, Hivemind, etc.) • Highly scalable (SEDA and Distributed Messaging)

13. Some Mule Supported Technologies Tcp Http VM SSL System Stream Jdbc Axis AS400 Data Queue Ftp Glue Space GigaSpaces XMPP File Udp Multicast Jms Rmi Ejb Email Resource Adapter Soap Oracle AQ Quartz Xfire JBI Spring Extensions Pico Extensions Plexus Extensions HiveMind Extensions Jotm Support Acegi Security PGP Security

14. Exposing Services public class LoanBrokerImpl implements LoanBroker { public LoanQuote createQuote( QuoteRequest req) {…} } LoanBroker.java mule-config.xml <!–- descriptor --> <mule-descriptor name=“loanBroker“ implementation=“loanBroker"> <inbound-router> <endpoint address=“axis:http://host/loanBroker” /> <endpoint address=“vm://vmLoanBroker” /> </inbound-router> </mule-descriptor> spring-context.xml <bean id=“loanBroker” class=“LoanBroker” />

15. Mule Architecture Guide(from mule.codehaus.org) Component Endpoints

16. Multiple Services • We want support four new banks in our system and offer the consumer • the best rate. But: • Not all of them have web services, some use JMS, some use EJBs. • Not all banks write all loans, so we acquired SmartLender Rule Base, • a .NET service that will help us figure out which banks will • offer on which loan requests. • Sounding like an Accidental Architecture. Some issues are: • We don’t want a bunch of logic in our • existing LoanBroker based on which Bank? • How are we going to get the response back to the user • in any sort of reasonable time?

17. Loan Broker(from EIP book)

18. Lessons Learned • Concentrate on Interface Definition over Component Design (its hard). • Configuration explosion is easy (you must standardize). • Immature Development model can make things difficult (asynchronous, routers, transformers, etc.). • State management makes it difficult to be truly service oriented. • Use iterative, test driven development. • Get high level buy in

19. Who’s using this stuff? Mule: • HP • Sony • Deutche Bank • CitiBank

20. Other Real World Application Used network concepts of an ESB to build data collection system over millions of embedded devices. • Handle Proprietary Network Protocols using transformers and driver services • Facilitate parallel processing over large amounts of data using ESB patterns. • Integrate with external ERP and network management systems to manage the installation and maintenance of installed devices.

21. More Information • mule.codehaus.org – Mule Web Site • Enterprise Integration Patterns – Gregor Hohpe, Bobby Woolf • http://www.atlantacs.com/ • Atlanta CS – bc@atlantacs.com

22. Questions?