Using an ESB to Build a SOA SOA/ESB/Legacy Integration Bob Sadler April 2008
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Using an ESB to Build a SOA SOA/ESB/Legacy Integration Bob Sadler April 2008
Using an ESB to Build a SOA SOA/ESB/Legacy Integration Bob Sadler April 2008 E54B Advanced Architecture Technologies & Solutions For Internal MITRE Use © 2007 The MITRE Corporation. All rights reserved Agenda What is an ESB? Standards supported What are the benefits? What do you do with it? Notional ESB architecture ESB Features How does an ESB work? Pros and Cons of using an ESB to build a SOA © 2007 The MITRE Corporation. All rights reserved What is an ESB? ESB – Acronym for Enterprise Service Bus Middleware/integration backbone that ties applications, services, and resources together within a business area Connects Web services, J2EE, .NET, B2B, Portals, and Legacy applications (i.e., databases, ERPs, CRM, programs, etc.) Defines service mediation (i.e., intelligent message routing, transformation, and monitoring) Allows publishing and discovering of services (WSDL/UDDI) Enables the connection of software running in parallel on different platforms, written in different programming languages, and using different programming/data models Provides service governance, security, and error handling © 2007 The MITRE Corporation. All rights reserved Generic ESB Architecture Legacy Applications .NET Apps J2EE Apps Portal Enterprise Service Bus Web Services B2B (Partner Systems) © 2007 The MITRE Corporation. All rights reserved What are the benefits? Simplifies the integration process and the reuse of business components Adapts easily to new business requirements Easy to use, lower-cost, and standards-based integration Enables incremental application development and deployment, thus reducing risk and up-front investments Centrally managed © 2007 The MITRE Corporation. All rights reserved Standards Supported WSDL, SOAP, UDDI, WS-Addressing, WSReliableMessage, WS-Security, WS-Policy XML, XML Schema, XSLT, XPath, and XQuery JMS, JCA, J2EE © 2007 The MITRE Corporation. All rights reserved What do we do with it? ANSWER: Integrate Applications Most organizations have legacy systems, and new applications that they want to build Many of the legacy systems need to be integrated along with the new applications Many of the legacies are in a client/server configurations (tightly coupled) Some of the new applications could be SOA © 2007 The MITRE Corporation. All rights reserved Notional ESB Architecture Service Registry Web Service Apps Business Process Mgmt (BPM) Test Manager Portal Enterprise Service Bus Service Management Data Service Layer DB DB © 2007 The MITRE Corporation. All rights reserved User Capabilities Can input requests, services, and commands through client application or portal Can view/output responses, services, and commands through client or portal Can define business processes/services through Business Process Management (BPM) Can orchestrate business processes with Business Process Execution Language (BPEL) Can create/maintain/execute policies (i.e., governance) through service registry/repository Can have service and transport-level security Can develop/implement/test through test management tools Can integrate databases through Data Service Platform © 2007 The MITRE Corporation. All rights reserved Vendor Specific Products “My Experience” ESB – BEA AquaLogic Service Bus (ALSB) Data Service Layer – Composite Data Service Platform Databases – Oracle 10g Test Manager – iTKO LISA Portal – BEA AquaLogic Portal © 2007 The MITRE Corporation. All rights reserved ALSB Features (1) Intelligent routing – Message routing according to XQuery-based policies or callouts to external Web services – Support for both point-to-point and one-to-many routing scenarios to support request-response and publish-subscribe models – Dynamic routing destinations that enable service destinations to be set dynamically in the proxy pipeline. External rules can be configured to feed the actual business service to be routed at run time Message brokering – Support for multiple messaging models including synchronous, asynchronous, and publish-subscribe – Support for multiple message formats including SOAP, SOAP with attachments, XML, structured non-XML data, raw data, text, and email with attachments – WS-I compliance for SOAP/HTTP messages © 2007 The MITRE Corporation. All rights reserved ALSB Features (2) Message transformation – Validates incoming messages against schemas – Dynamic service selection, based on message content or headers with the ability to transform messages based on the target service Message transformation based on XQuery or XSLT – Multiple formats: XML and structured non-XML data Service bus security – Supports authentication, encryption and decryption, and digital signatures as defined in the Web service security (WS-Security) specification – Uses SSL to support traditional transport-level security for HTTP and JMS transport protocols – Supports one-way and two-way certificate based authentication – Supports message-level security – Supports HTTP basic authentication © 2007 The MITRE Corporation. All rights reserved ALSB Features (3) Service Level Agreement (SLA) – Administrators can set SLAs on a variety of attributes including throughput times, processing volumes, success/failure ratios of messages processed, number of errors, security violations, and schema validation issues – Administrators can configure alerts for SLA rules violations and trigger automated actions, and send alerts to the console, or email Error handling – Allows you to configure your system to format and send error messages, and return messages for consumers of services who expect a synchronous response Testing – Provides a built-in test console in the development environment – Allows you to test inline XQuery expressions used in the message flow Logging and monitoring – You can gather statistics about message invocations, errors, performance characteristics, messages passed, SLA violations, etc. © 2007 The MITRE Corporation. All rights reserved How does ALSB Work? Application client – Service consumer ESB – Proxy service – Intermediary Web service that exchange messages with client; Proxy services are published by ALSB; defined in terms of WSDLs, pipelines, routes, and branches; sends and formats messages to appropriate business services – Business service – Enterprise services that ALSB will route messages to; any service not implemented in pipeline; represent services external to ALSB; client stub Existing service – Back-end services © 2007 The MITRE Corporation. All rights reserved Intelligent Message Brokering Appl Client Proxy Business Service Service Backend Service © 2007 The MITRE Corporation. All rights reserved SOA Development © 2007 The MITRE Corporation. All rights reserved Cons of using an ESB to Build a SOA Don’t use ESB-oriented architecture, if it does not have “business value”. SOA must be based on business requirements An ESB is a means to an end, not the end itself SOA approach consists of several components such as service producers, service consumers, service registries and repositories. These components must be defined and developed first, then integrated with an ESB Integrating ESB with other software may be difficult, particularly legacies Organization may have to develop new skills, techniques, and technologies © 2007 The MITRE Corporation. All rights reserved Benefits of ESB Prototype Do an ESB prototype first Starting point for developing and evaluating tangible and reusable SOA services and products Enables a means of testing services with portals, databases, and other applications Provides a means of training staff on SOA/ESB concepts, development (i.e., SOA/ESB analysis, design, implementation, and testing) and tools Provides “lessons learned” before you build a production SOA integrated environment Production cost estimates and development schedules can become more accurate and realistic because of the experience gained from building an ESB prototype © 2007 The MITRE Corporation. All rights reserved SOA Development © 2007 The MITRE Corporation. All rights reserved SOA Guiding Principles Gain buy-in to service-oriented design from senior executives and stakeholders, based on the benefits they will receive from a SOA approach. Share “lessons learned” among SOA development and implementation teams to avoid duplicating earlier mistakes Create a SOA roadmap/development plan based on enterprise business strategy Define IT design and development policies, best practices, and standards Educate staff about SOA policies, practices, products, and tools Survey SOA range of technologies and techniques Implement SOA governance process that ensures teams are following design and development policies, architecture, and best practices Regularly measure the results of the SOA adoption in terms of added business values to the organization Leverage your legacy systems (e.g., existing architecture, infrastructure, and investments) Define a step-by-step procedure detailing how the SOA will be tested © 2007 The MITRE Corporation. All rights reserved Service Lifecycle Phases Planning Define/Develop services Discover services Integrate services Orchestrate services Secure services Manage services Test services Deployment Access services Analyze SOA/services and environment Monitor services © 2007 The MITRE Corporation. All rights reserved Planning Define the business value upfront (i.e. make a business case) Define the scope of SOA (i.e., business processes, number of services, organizations, external users, etc.) Establish boundaries and alignments with current and future business and IT initiatives Use a phased approach, starting with a single, low-risk application or a pilot program that spans business functions and eventually expand to an enterprise SOA Use architecture guidelines, requirements, and policies Define SOA standards Define roles and responsibilities Assess the maturity of the current and desired target state, followed by a roadmap for transformation toward SOA Define SOA tasks Plan task schedule and resources Start the governance process © 2007 The MITRE Corporation. All rights reserved Define/Develop Services Create service candidates by defining roles and collaboration as stated in business processes Identify candidates for potential business services from business model Potential business services should be reusable Design and build services that correspond to specific steps within a business process Identify services that can be combined into a composite service or application for carrying out a specific business function Use a Business Process Management (BPM) tool © 2007 The MITRE Corporation. All rights reserved Discover Services Define the service registry/directory Service directory acts as service broker between service provider and service consumer. It registers the services through its metadata or service contracts (i.e., it hold data about the services). Define service providers and consumers Service provider is a person, department, organization, or application that offers the service. It registers service contracts to the appropriate service –brokering nodes. Define Service Level Agreements/Contracts and metadata. Service consumer is a person, department, organization, or application that finds services with which its client would like to bind and interact. The service consumer may query service broker to find contracts and the metadata associated with services (i.e., service location, methods or remote services, message input/output formats, policies, and other parameters that a client uses to bind to a service) Service broker is an entity that facilitates registration, location, discovery, retrieval, synchronization, replication, and/or delivery of service © 2007 The MITRE Corporation. All rights reserved Integrate Services Integrate services with other services, applications or IT systems such as databases, data transformation services, reliable message delivery with routing, monitoring, and management (i.e., could be ESB and Service Management tools ) Integration often requires transformation of data to map between different data schemas, as well as dynamic routing for connecting the appropriate services at run time. This can be done in a Data Service Platform (DSP). © 2007 The MITRE Corporation. All rights reserved Orchestrate Services Orchestration is the combining of services into seamless, reliable process flows It differs from integration, because orchestration is the sequencing of services to fulfill a business task or process Orchestration is also called “gluing” services together into flow logic Can be done in Business Process Execution Language (BPEL) and Business Process Management (BPM) © 2007 The MITRE Corporation. All rights reserved Secure Services Define service security policies Define user access in SOA environment (i.e., authorizing and authenticating users, as well as provisioning them and managing their identities) must be mapped out before potentially sensitive information is exposed as a service Identify services and data with security requirements Provide information security controls to security requirements May be implemented in the Service Registry and/or ESB ESB provides message and transport level security Web service security standards can be applied (i.e., WSSecurity, SAML, SSL, XML-Signature, XML-Encryption, etc.) © 2007 The MITRE Corporation. All rights reserved Manage Services Define Service Level Agreements (SLA)s for services, and how to enforce them Create SOA operational policies for daily operations, maintenance, auditing and billing (if appropriate) of services Define metrics for service performance May be implemented and enforced in Service Registry and Service Management © 2007 The MITRE Corporation. All rights reserved Deployment Deployment Considerations: – – – – – – – – – Cross domain requirements Physical facilities/power Does services require 24/7 availability What are the security and scalability requirements Maximum number of concurrent users Service transaction time requirements Tools, training, and technologies Configuration and version control C&A and COOP/DR requirements © 2007 The MITRE Corporation. All rights reserved Service Access Services are typically exposed to users through a portal or a composite Web application May also be exposed through wireless devices such as cell phones and handheld devices SOA environments support multi-channel access to services and enable organizations to adapt user interfaces without modifying underlying services © 2007 The MITRE Corporation. All rights reserved Analyze Services Periodically analyze services, events, and business processes involved in the business operations Define how operational managers and users can effectively monitor, analyze, and respond to timesensitive issues Identify bottlenecks and other problems in the process and alert the appropriate personnel when a particular event warrants attention Analyze if all requirements are being met © 2007 The MITRE Corporation. All rights reserved Monitor Services Monitor the service execution and results Ensure that the services are reliable, available, and constantly monitored for exceptions or failures Services can be monitored through the ESB, and performance tested with a Service Test Manager © 2007 The MITRE Corporation. All rights reserved SOA/ESB Lesson Learned 1 Do an ESB prototype first ESB as an integration and SOA solution is still a new technology – Getting trained and skilled people may be a problem – Integrating ESB with other software may be difficult Standards and best practices are still maturing Organization may have to develop new skills, techniques, and technologies Management must endorse and enforce governance from the beginning Security must be considered from the beginning (i.e., SOA Security, Web Service security, Defense-in-Depth, DoD compliance, etc.), and you can never start the C&A process too early © 2007 The MITRE Corporation. All rights reserved SOA/ESB Lesson Learned 2 Performance requirements (i.e., reliability, availability, scalability, transaction time, response time, etc.) should be defined and tested, performance may be an issue SOA may not be the answer for all legacy integrations Demonstrate the ESB capabilities to stakeholders Use vendor experts as much as possible to assist with development Provide training to users © 2007 The MITRE Corporation. All rights reserved The End © 2007 The MITRE Corporation. All rights reserved