Architecture, Styles, and Service Oriented Architecture Richard Osborne September 22, 2006

Architecture Defined the art of creating an actual, implied or apparent plan of any complex object or system a subjective mapping from a human perspective to the elements or components of some kind of structure or system, which preserves the relationships among the elements/components

IT or Systems Architecture Many definitions the representation of an engineered system, and the process and discipline for effectively implementing the design(s) for such a system. Such a system may consist of information and/or hardware and/or software The fundamental organization of a system, embodied in its components, their relationships to each other and the environment, and the principles governing its design and evolution. From ANSI/IEEE 1471-2000

IT or Systems Architecture A representation of a system in which there is a mapping of functionality onto hardware and software components, a mapping of the software architecture onto the hardware architecture, and human interaction with these components. From the Carnegie Mellon University's Software Engineering Institute An architecture description is a formal description of a system, organized in a way that supports reasoning about the structural properties of the system. It defines the [system] components or building blocks...and provides a plan from which products can be procured, and systems developed, that will work together to implement the overall system. It thus enables you to manage...investment in a way that meets [business] needs. From The Open Group Architecture Framework

IT or Systems Architecture All have some common elements: Structure Components Relationships Purpose Plan

Enterprise Architecture Applying IT Architecture disciplines to an enterprise Outside-in, strategy-driven, top-down viewpoint Alignment – the “holy grail” the practice of applying a comprehensive and rigorous method for describing a current and/or future structure and behavior for an organization's processes, information systems, personnel and organizational sub-units, so that they align with the organization's core goals and strategic direction

Enterprise Architecture FEA – Federal Enterprise Architecture Core Principles: Business-driven Proactive & collaborative across the Federal government Architecture improves the effectiveness and efficiency of government information resources No IT investment without a business-approved architecture

Enterprise Architecture Alignment of business strategy & IT investments Architecture is the translation of business strategy into technical strategy Use of a framework to: Document current state Define the future state desired capabilities Create a roadmap to get there There are many reference frameworks Zachman FedArch E2A TOGAF

Enterprise Architecture All have some combination of the following concepts: Business Information Technology Application Contextual Conceptual Logical Physical

Reference Architecture Reference architecture - a style or method a coherent design principle used in a specific domain describes the kinds of system components, their responsibilities, dependencies, possible interactions, and constraints. basis for designing the system architecture for a particular system. the architect can select from a set of well-known elements (standard parts) and use them in ways appropriate to the desired system architecture

Reference Architecture Pre-defined architectural pattern Designed and proven for use in particular business and technical contexts Often harvested from previous projects Best practices Abstract solutions from many previous attempts Example - Open System Interconnection model defines a networking framework for implementing protocols in seven layers

Service Oriented Architecture A collection of services that communicate with each other A service is a function that is well-defined, self-contained and does not depend on the context or state of other services From simple data passing to two or more services coordinating (orchestrating) some activity (business process) Not a new concept

Service Oriented Architecture Service Oriented Business Applications (Loosely Coupled, Business Services as Assets) Application Silos with Components (Tightly Coupled and Limited Reuse) Service Oriented Architecture Monolithic Architecture (Tightly Coupled, Application Silos) Component Based Architecture Monolithic Architecture Time

Service Oriented Architecture Next stage of integration Services (SOA) What’s Next? Business Process Management EAI Message Processing Remote Object Invocation Sub-routines & Remote Procedure Calls Monolithic Architectures Pre 50’s - 60’s 70’s - mid 80’s 80’s - Mid 90’s Mid 90’s to Early 00’s Late 90’s Today Future

Why is Integration Important? Investments made in “legacy” systems Trillions of $ over the past 40 to 50 years Remember Y2K? Mainframe Distributed Client-Server Web Application Packages such as ERP Cost and Time to develop & deploy new business functionality Rates from $30/hour (off-shore) to $300+/hour A small 5 person year project (10,000 hours) can easily cost in excess of $2M and take a year to deliver

Why is Integration Important? Why develop a new system/business function when you already have it? Is it “locked up” in a different technology? The cost to maintain two of the same is not 2X but 3X .. Or more SOA is a way to re-use the assets that most organizations already own Break down the existing systems into components that can be combined in new ways A flexible, standards-based integration method is needed

Why is Integration Important? EAI SOI Custom Point-to-Point Integration uses technology aware bridges between application components; very brittle for changes. EAI uses broker-specific adaptors which provide pre-built connectivity to a wide variety of applications & platforms; less brittle for changes than P2P. SOI integrates applications & platforms using service interactions & an ESB; is the least brittle for changes.

How do we achieve integration? The Silo – monolithic architecture User Interface Business Logic Data Access Data

How do we achieve integration? Separation of Concerns User Interface Integration Layer Business Logic Integration Layer Data Access Integration Layer Data

SOA Definitions - Viewpoints a set of services that a business wants to expose to their customers and partners, or other portions of the organization an architectural style which requires a service provider, requestor and a service description a set of architectural principles, patterns and criteria which address characteristics such as modularity, encapsulation, loose coupling, separation of concerns, reuse, compose-ability and single implementation a programming model complete with standards, tools and technologies such as Web Services

SOA Reference Architecture Data Architecture and Business Intelligence Monitoring Infrastructure Service QoS, Security, Management, and Integration (Enterprise Service Bus Approach) consumers business processes process choreography services atomic and composite service components operational systems Service Consumer Service Provider AJAX Portlets WSRP B2B Other OO Application Custom Packaged Governance

SOA's Standards Foundation BPEL (Business Process Execution Language): a standard for assembling sets of discrete services into an end-to-end business process J2EE 1.4: the current version of Java 2 Platform, Enterprise Edition, with APIs for deploying and managing Web services JSR 168: standard for portal and portlet interoperability JSR 181: an API for Web services metadata annotation SOAP (Simple Object Access Protocol): a W3C-approved standard for exchanging information among applications UDDI (Universal Description, Discovery, and Integration): an OASIS-approved standard specification for defining Web service registries WS-I (Web Services Interoperability): an open industry organization promoting Web services interoperability across platforms, operating systems, and languages WS-Reliability (Web Services Reliability): a SOAP-based protocol for exchanging SOAP messages, with delivery and message-ordering guarantees WS-Security (Web Services Security): a SOAP-based protocol that addresses data integrity, confidentiality, and authentication in Web services WSDL (Web Service Description Language): a W3C-approved standard for using XML to define Web services WSIF (Web Services Invocation Framework): an open source standard for specifying, in WSDL, EJB implementations for the Web server WSRP (Web Services for Remote Portlets): an OASIS standard for integrating remote Web services into portals XML (Extensible Markup Language): a data markup language for Web services

Conclusion Architecture plays a role in Enterprise IT EA is often used to align what IT does and plans to do with the business strategy There are frameworks that help how to think about the problem There are reference architectures to help how to create an approach There are architectural patterns to help in thinking how to build and deploy solutions There are architectural styles that can be applied in solution design