The ESB as a Pattern for SOA o Exploring the Capabilities of an ESB o ESB Components o Process Choreography and the ESB o JSR-208 JBI Specification and the Impact on an ESB o Open Source ESB Projects o Summary 2
o There is no industry-agreed upon definition of what an ESB is o Some questions to consider : Is it a Pattern? Is it a Product? Is it an Architectural Component? Is it a Hardware Component? (i.e. DataPower Xl50) 4
"[This ESB] is an enterprise service bus which simplifies the integration and flexible reuse of business components using a standards-based , service- oriented architecture (SOA). Free of the inflexible and costly customization required by other middleware technologies , [this ESB] lets architects dynamically configure the reliable connection, mediation and control of services and their interactions ."
"[This ESB] is an Enterprise Service Bus (ESB) and SOA toolkit built from the ground up on the semantics and APls of the Java Business Integration (JBI) specification JSR 208 . It is lightweight and easily embeddable, has integrated Spring support and can be run at the edge of the network (inside a client or server) , as a standalone ESB provider or as a service within another ESB. You can use [This ESB] in Java SE or a Java EE application server. The aim of [This ESB] is to allow integration components and services to be integrate in a vendor independent way, allowing users and vendors to plug and play. "
"[This ESB] offers the first end-to-end, 100°/o Web services-based Enterprise Service Bus, spanning service creation through sophisticated service orchestration with native BPEL support . New features include deep support for a wide range of XML and Web services standards , Multi-protocol messaging , routing, and adapters, including full support for WS-Rel iableMessaging and the option of a fully integrated version of the JBoss JMS , extensive and intuitive transformation support for XML and non-XML applications and data, and complete support for BPEL 1.1 workflow and routing, including a suite of powerful Eclipse-based tools for the design, deployment, and management of complex workflows ."
define an ESB? "An Enterprise Service Bus (ESB) is a new architecture that exploits Web services, messaging middleware, intelligent routing, and transformation. ESBs act a a lightweight, ubiquitous integration backbone through which software services and application components flow."
of The ESB ESB Architecture Context o In the move towards SOA, client applications are decoupled from services. The ESB provides the communication bridge ... Client Application Service Provider (Java/EJB) Service Provider (GIGS/Mainframe) II Client Applicat ion ! Enterprise Service Bus Service Provider (Java/EJB) Service Provide r (GIGS/Mainframe)
The ESB The ESB Helps Facilitate The Following: o Service Location Transparency o Sharing of services across the enterprise o Ability to separate Business Services from Service Implementations 13
Implementation Service Business Service Def Place Trade WSDL Client Application Place Trade The Role of The ESB Implementation Services are coded within the Service Providers Business Services are exposed to client as a service name and specified input and output structures Enterprise Service Bus (i.e. through Java/EJB) (i.e. through WSDL) save TradeOrder() Service Provider 14 I I • • - • Java V Source Code for save TradeOrder()
·------- --- .. ----- -------- -- -- ------ ---- -- -- Transaction Management --- -- · Message Enhancement Enterprise Service Bus Service Orchestration ------ Protocol Transformation ---- -------- The Role of The ESB Service Mapping ------- ~ Process Choreography Message Processing
to a particular service provider based on deterministic or variable routing criteria Types of routing to consider Static or Deterministic Routing Content-based Routing Policy-based Routing Complex Rules-based Routing The Role of The ESB e8 Routing
structure and format of the incoming business service request to the structure and format expected by the service provider Some Examples Include: XML D LJ XML XML D LJ COBOL Copybook Object 8 :J XML The Role of The ESB e8 Message Transformat ion
modify the information contained in the message as required by the service provider Types of Message Enhancement Date format conversion Supplement data not included in original message Data conversion (i.e. spaces to zero) Rules-based Enhancement The Role of The ESB e8 Message Enhancement
type of protocol from the consumer as input (i.e. SOAP/JMS) and communicate to the service provider through a different protocol (i.e. I/OP) The Role of The ESB e8 Protocol Transformation A form of message transformation concerned with the message structure , not the message payload Has both physical connection attributes as well as logical connectivity attributes Examples SOAP/JMS DD IIOP XML/HTTP DD CICS/MQ XML/HTTP OD RMI/IIOP SOAP/MQ DD ATMI XML/HTTP DD OTMA
//ESB Must be able to process HTTP GET or POST Request //Extract XML From SOAP SET Output.XMLPayload = SOAP.body.xml //Create Protocol-specific Message Structure SET Output . Properti es.MessageSe t='l20ABTG002001 '; The Role of The ESB e8 Protocol Transformation SET Output.Properties .MessageType='PSFN _BNCB_PEND ITM_CI'; SET Output.Propert ies.MessageFormat= 'CwXML'; SET Output .MQMD .Format='MQHRF2 '; SET Output.MQRFH2 .(MQRFH2 .Field)Version= 2; SET Output.MQRFH2 .(MQRFH2 .Field)Format= 'MQSTR '; SET Output .MQRFH2 .(MQRFH2 .Field)NameValueCCSID= 1208; SET Output .MQRFH2 .(MQRF H2.Field)CodedCharSet ld=1208 ; SET Output.MQRFH2.mcd.Fmt= 'CwXML' ; SET Output.MQRFH2.mcd.Set= '120ABTG002001'; SET Output.MQRFH2.mcd.Type= 'PSFN_BNCB_PENDITM_CI'; • • •
business service into the corresponding service implementation and provide binding and location information The Role of The ESB e8 Service Mapping Could be implemented through XML, a database, or embedded within the Mediator ESB component Usually contains the following core information Implementation Service Name Service Protocol and binding information Protocol-specific info (i.e. timeouts, failover location) Service-specific routing information
and perform request management by accepting an input request and ensuring delivery back to the client via message synchronization The Role of The ESB e8 Message Processing For updates this might require the use of XA or messaging sync points to ensure guaranteed message process ing and delivery Client Application 1 Input Request Queue Enterprise Service Bus - - Output Request Queue i - - Error Notification Queue f
e8 Process The ability to manage complex business processes that require Choreography the coordination of multiple business services to fulfill a single business service request o Usually BPEL based Process Choreography can be thought of as a manifestation of a use case or business process PlaceFixed Income Trade Each of the business process nodes can be an independent business service CreateOrder SelectBid PlaceTrade ExecuteTrade
coordination of multiple implementation services The Role of The ESB Service Orchestration Can be BPEL based but is usually implemented through inter-service communication or aggregate services Difference between Service Orchestration and Process Choreography is based on the type of service being coordinated Process Choreography n Business Services Service Orchestration Implementation Service
single unit of work for a business service request by providing a framework for the coordination of multiple resources across multiple disparate services The Role of The ESB Transaction Management Specifically, the ESB should provide a compensatory transactional framework for a service request WS-Coordination JSR-95 Activity Service
Security The ability to protect enterprise services from unauthorized access In SOA there are no more silos; services become visible to the entire enterprise through the ESB The 4 "A's" of Security Authentication Authorization Auditing Administration ESB should provide authentication, authorization, and auditing ESB should access a security manager for authentication and authorization rather than have the direct responsibility
o There is no one single product that can effectively do all of the capabilities required of an ESB o An ESB can be broken down into the following components Mediator Service Registry Choreographer Rules Engine ESB Mediator t Choreographer Rules Engine Service Registry
The Role of The ESB Routing Communication Message Transformation Message Enhancement Protocol Transformation Message Processing Error Handling Service Orchestration Transaction Management Security
* Choreographer would be responsible for these capabilities only if it is the entrypoint into the ESB The Role of The ESB Message Processing* Process Choreog raphy Transaction Management* Security*
Engine * Specifica lly Rules-based Routing, Message Transformation, and Message Enhancement The Role of The ESB Routing* Message Transformation* Message Enhancement *
process choreography sit above or below the Mediator? Choreography as the ESB Entry Point Mediator as the ESB Entry Point Either as an ESB Entry Point Recommendation Mediator as the ESB Entry Point (Choreography Below) Based on small 0/o of services that must be choreographed Better Performance Better Scalability Less Complexity 37
ESB Entry Point Client Application ESB Mediator i Choreographer Service Registry Service Provider The Role of The ESB Advantages o Good Performance o Good Scalability o Reduced Complexity : Only those services requiring Choreography go through the Choreographer
ESB Entry Point Client Application ESB Choreographer Service Registry Mediator Service Provider The Role of The ESB Considerations Performance Issues o Maintenance Issues o Complexity Issues o Do ALL services require BPEL- based process coordination?
Mediator Relationship Choreographer and Mediator As The ESB Entry Point Client Application + ... .. ESB 7 / i Choreographer Mediator r- - -- Service Registry Service Provider Considerations Cl Client responsib le for determining service characteristics Capabi lities shared by multiple ESB components Message Processing Transaction processing Security No good separation of responsibility within ESB components
o Choreography contains business logic - does it really belong in an ESB? ESB is an infrastructure component Should business rules reside outside the ESB in the client?
Java Business Integration (JBI) Specification o The goal of JBI is to create a standards-based architecture for integrating middleware components to perform ESB capabilities o The JBI Spec is not concerned about how external consumers or service providers interact, but rather how internal consumers and providers interact o JBI is dependent on J2SE but not J2EE o JBI defines two types of components Service Engines (SEs) Binding Components (BCs)
JBI Advantages and the effect on Commercial ESBs o Third-party or Custom Service Engines (SE) and Binding Components (BC) can be swapped in and out without impacting applications or • services o Avoids "Vendor Lock-in" o Allows for "Best of Breed" technologies and solutions o We can mix Open Source and Commercial solutions o We can swap in and out integration services (i.e. capabilities) we don't need, creating a lighter-weight solution that meets our specific needs o Is this the wave of the future for ESBs?
Mule o Lightweight Messaging Middleware Framework that manages UMOs (Universal Messaging Objects) o UMOs contain communication endpoints that know how to receive and send requests UMO Appl ication Mule Container UMO Application External Service Provider
ESB JMXAdmin Tools WSIF Installation JavaMail Deployment File Control HTTP Normal ized Message Router Drools PXE JCache Groovy The Role of The ESB Monitoring ActiveSOAP Quartz XSLT
learned? There is a beer made by Redhook called ESB An ESB can defined through its capabilities , specifically the ones important to us Reviewed 10 Core Capabilities and what they really mean Reviewed the components that make up an ESB and the capability mapping for each component How Choreography can play a part within an ESB What is JBI all about (Standards-based Pluggable Architecture) Open Source Solutions
http://www.redhook .com Mule - http://mule.codehaus .org ServiceMix - http://servicemix .org Please fill out the session evaluation W. Mark Richards - wrichard@us .ibm.com 53
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