Understanding Enterprise Service Bus (ESB) for Effective Integration

1. An Overview of JBI • May 2007

2. About Me • Application Architect with Daugherty Business Solutions • Working on a Fraud Detection Platform • NOT doing integrations right now :-( • Implemented several of Hohpe’s patterns in JMS

3. Part 0 - The “level-set” • We all know Java, except Stacey • We’ve played with Web services and WSDL • We know <sarcasm> and love </sarcasm> XML • May have used JMS or another messaging provider, IBM MQSeries, MSMQ etc.

4. A motivating example... • Consider the traditional client/server application...

5. Client/Server Problems • Tight coupling • Protocol independence? (TCP/IP connection-oriented protocol) • No platform independence - 32 or 64 bit, PC to Mainframe, etc. • No recovery • No failover

6. Enterprise “Opportunities” • Data is transported between apps • Data needs to be understood by both apps • Require a communication channel to move the information • Two endpoints must be available • Information is transported as a message

7. Definitions...

8. Service-Oriented Architecture (SOA) • A design approach (paradigm) that encapsulates application logic in a set of services that interact using a common communications protocol. • Communications protocols can be XML-based Web services, JMS, CORBA etc.

9. Enterprise Service Bus(ESB) • Data grid capable of spanning the Enterprise globally • Standards-based integration • Integrates with anything that supports SOAP and Web services • Highly distributed, deployed services

10. ESB continued... • Distributed Data transformation • Remote configuration and management • Uses XML as the lingua franca of communication • Real-time Business data

11. Web Service • Based on open standards • Discoverable, distributed Service • XML based interaction • Platform agnostic • Vendor neutral

12. Web Service Roles • Services can assume different roles when involved in different integration scenarios: • Service provider • Service requestor • Intermediary • Initial sender • Ultimate receiver

13. WSDL (whiz-dul) • WSDL 1.1 originally submitted by Ariba, IBM and Microsoft • XML document describing a Web service • Binding section “operation” attribute is the exposed service • Each operation requires a SOAP action to be defined

14. Document Structure <definitions> <types> </types> <message> </message> <portType> </portType> <binding> </binding> </definitions>

15. Document Sample <definitions name=”OrderingService”> <message name=”placeOrderRequest”> <part name=”custName” type=”string”/> <part name=”prodNum” type=”string”/> </message> <message name=”placeOrderRequest”> <part name=”custName” type=”string”/> <part name=”prodNum” type=”string”/> </message> <portType name=”OrderingPort”> <operation name=”placeOrder”> <input message=”placeOrderRequest”/> <output message=”placeOrderResponse”/> </operation> </portType> <binding type=”OrderingPort” name=”OrderingBinding”> <soap: binding style=”rpc” transport=”http”/> <operation name=”placeOrder”/> </binding> <service name=”SalesOrderService”> <port binding=”OrderingBinding”> <soap:address location=”http://...”/> </port> </service> </definitions>

16. SOAP (not the cleaner) • A W3C Spec, originally submitted by Microsoft • A protocol for exchanging XML-based messages and accessing Webservices • Allows for RPC and Document styles of communication • SOAP message consists of Envelope and Body

17. Sample SOAP Request <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"> <soap:Body> <getProductDetails xmlns="http://warehouse.example.com/ws"> <productID>827635</productID> </getProductDetails> </soap:Body> </soap:Envelope> Source: http://en.wikipedia.org/wiki/SOAP

18. Sample SOAP Response <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"> <soap:Body> <getProductDetailsResponse xmlns="http://warehouse.example.com/ws"> <getProductDetailsResult> <productName>Toptimate 3-Piece Set</productName> <productID>827635</productID> <description>3-Piece luggage set. Black Polyester.</description> <price currency="NIS">96.50</price> <inStock>true</inStock> </getProductDetailsResult> </getProductDetailsResponse> </soap:Body> </soap:Envelope> Source: http://en.wikipedia.org/wiki/SOAP

19. Messaging • Some form of data exchange between a provider/sender and a consumer/receiver of information through an Enterprise channel

20. Message...Hohpe’s • A data record that the messaging system can transmit through a “Message Channel” • Consists of header information used by the messaging system that describes the data being transmitted, its origin, its destination etc. (Note: Message Routing semantics)

21. Message...Buschmann/Henney/Schmidt • Message queuing systems, such as IBM MQSeries or Microsoft MSMQ messages, define a user-defined body with which higher layers can implicitly transmit user data. (Infers Message Routing intelligence)

22. Message...Krafzig/Banke/Slama • Consists of header and a payload. The structure of the header file is usually predefined by the system and contains network routing information

23. So, how does JBI define a Message? • Called a Normalized Message • Consists of 3 parts: • a payload - XML document that conforms to WSDL message type • message properties/metadata (a.k.a routing information) • message attachments

24. What do they all agree on? • A message contains a data payload and supplemental information that allows it to be intelligently routed through some sort of message delivery channel

25. Basic Integration • Sending messages through a channel that may, or may not, provide transformations and/or business logic between endpoints.

26. So what were integrations prior to JBI?

27. Integrations, silly!

28. Integration Patterns

29. Integration Components • Application(s) • Channel • Message • Endpoints • Message Router

30. Applications • Can be either a provider or consumer of a particular service • Acts as an Endpoint, stay tuned...more on this in a few minutes

31. Channel • Logical address, not physical • Agreed upon by both consumer and producer • A good example: http://www.foo.com • JMS: Topic or Queue

32. Message • A representation of “some” data • The payload that either consumer or producer care about • E.g. Raw bytes, formatted text (XML) etc. • Metadata describing routing information through ESB

33. Endpoints • Initiator or receiver of information • one end of the entire integration • Or can be a router of information to other consumers • JMS: Topics have subscribers

34. Message Router • Logcially routes messages based on payload, content or other metadata • Example Patterns: Message Broker, Message Dispatcher, Splitter, Filter

35. Message Transformations • When sender and receiver do not agree on the format • Converts a message from one format to another • Hohpe’s patterns: Message Translator, Content Enricher, Normalizer etc.

36. Ok John, get to the point!

37. Java Business Integrations

38. JBI - The What? • JSR 208, Standard Specification • Infrastructure and Component framework for integrations • JBI Components plug into the JBI Framework

39. JBI - What? part deux • Divided into Service Engine Components and Binding Components • Components communicate through mediated Message Exchanges

40. Service Engine (SE)Components • Plug-in components provide business logic, transformational services etc. • Some SE's can contain other SE's, “container of containers” • ServiceMix provides SE's for JMS, EJB, Drools, HTTP and many many more

41. Binding (BC) Components • Provide connectivity to components external to the JBI environment • Send and receive messages for some particular protocol and transports • Provide a sort of adapter for messages and the transport and protocol

42. JBI Management • Management Structure based on JMX • Standardizes: • Installation • Managing component lifecycle • Deploying services to components • Components can act as a container for other components

43. JBI Roles • Similar to JEE, based on roles for development and deployment • Integration Architect – designs the overall approach to solving integration problems • Integration Technologist – identifies particular services needed for solving integration problems

44. Roles continued... • System Administrator – installs, configures and monitors the JBI environment • JBI Component Developer – provides Java components that conform to the JBI-spec contracts

45. JBI Architecture • WSDL-based Messaging Model • Declarative (XML) service model • Supports plug-in components • Management configuration through JMX

46. WSDL Messaging Model • Produces or Consumes services using WSDL 1.1 or WSDL 2.0 specifications • Abstract Model • Concrete Model

47. Abstract Model • Message Types defined in XML schema • Operations defined with a name and a Message Exchange Pattern (MEP) and a type • Interfaces - collections of related operations (not the same as a Java interface) • Communication protocol neutral

48. Concrete Model • Build upon the Abstract Service Model • Maps abstract definition to communication protocol and communication endpoint • Binding type - communication protocol • Endpoints - designates endpoint information • Service - name, type and endpoint of service

49. Normalized Message Router (NMR) • Receives Message Exchanges from JBI components • Routes to appropriate handling component • Decouples Producers from Consumers enabling different processing

50. Normalized Message • Defined earlier • JBI’s “version” of a plain Message • Consists of 3 parts: • Message metadata for routing • Payload • Arbitrary attachments