Liquid. Hub Lunch & Learn Demystifying SOA: Concepts & Best Practices Prepared by: Ray Bordogna Partner & Chief Strategy Officer Liquid. Hub, Inc. Presented: Tuesday, February 26, 2008
2 Executive Briefing Outline § About Liquid. Hub, Inc. § Section I: §The Business Process § Section II: §The IT Environment § Section III: §SOA Introductory Concepts § Section IV: §SOA Implementation Considerations § Section V: §SOA Proof of Concept (POC)
3 About Liquid. Hub, Inc. #339 in 2005 List § Liquid. Hub is a systems integrator & technology consultancy focused on enabling the Agile Enterprise through our Strategy, Applications, Data, and Infrastructure solutions and an engagement lifecycle of planning, execution, and management. § Specific solutions include Enterprise & SOA, Enterprise Integration, Enterprise Portals, Content Management, and scalable Applications and Security Infrastructures. § With offices in Philadelphia, Boston, and Hyderabad, India, our more than 475 associates serve clients in Life Sciences, Financial Services & other key industries globally, at our sites or theirs. § Liquid. Hub’s Enterprise Services Transformation Roadmap (ESTR) helps organizations plan for technology simplicity and reusability, providing a roadmap to the Agile Enterprise. ESTR provides our clients with a clear process for evaluating business needs, identifying existing technology & process assets, and planning the implementation and integration of new technologies in a way that ensures technology reuse and lower total cost of ownership.
4 The Liquid. Hub Enterprise Services Architecture (ESA) Framework Enterprise Architecture Frameworks (e. g. , Zachman) Enterprise Services Architecture ESTR: (Integrated View) Service Orientation Services Definition: 1. Loosely Coupled - Abstracted - Platform Independent integrates Planning Approaches (e. g. , EAP) Enterprise Planning Methodology 2. Designed & Built for Agility 3. Articulating 4. Meaningful to the Service Consumer 5. Contract-based 6. Standards-based 7. Discoverable Reference Models (e. g. , TOGAF) Solution Methodology (Project) Service-Oriented Principles: 1. Federated 2. Traceable 3. Aligned with Business & IT 4. Evolutionary 5. Managed Governance Models (e. g. , TOGAF) ESA Reference Model 6. Application Neutral
5 The Liquid. Hub Enterprise Architecture Framework Business Strategy What markets do we compete in and how are we different? CAPABILITY 1 Business Architecture What processes support our capabilities? Process 1 Application (Services) Architecture What applications (services) enable our processes? Service 1 Data Architecture data support What Process 6 Process 12 Service 3 Service 6 Service 7 DB 1 our business? DB 12 Infrastructure Architecture What is the foundation of our business? Device 2 Device 13 Business Resource Architecture What is our optimal resource allocation? Financial Architecture What is our optimal investment portfolio? IT Business Expense: $XX Capital $YY IT Development: $XX Maintenance: $YY
6 The Liquid. Hub Enterprise Services Transformation Roadmap (ESTR) Program Management Governance Plan Model Business Architecture Model SDLC Methodology Refinement Business Service Domain Model Business Solution Delivery Roadmap Business Services Design Composite Applications Orchestration & Choreography Business Project Services Portfolio Implementation Management Business Process Optimization The Agile Enterprise Your Current Enterprise Information Architecture & Taxonomy Business Process Model Technology Services Reference Model Phases Work Streams Enterprise Data Model/ Semantic Model Metadata Repository Design Security Network Architecture Services Architecture Application Integration Platforms Blueprint Envision (Strategy and Plan) Program Management Enterprise Business Services Information Management Technology Shared Services Engineer (Architect/Design) Application (SOA) Platforms Federated Data Source and Data Services Network Infrastructure Services Execute Application Management Services (Develop/Implement)
7 The Liquid. Hub ESA Reference Model (Portfolio of Services) Business Architecture & Business Process Models Enterprise Business Services Business Applications Enterprise Packaged Applications Business Process Services Business Services Information Assets Business Services Domain 1 Domain 2 Customer Finance Orders Technology Shared Services Enterprise Presentation Services Enterprise Application Services Information Services Data Infrastructure Client Services Core Application Services Personalization Services Business Intelligence Business Process Integration Data Access Services Digital Asset Management Enterprise Platforms Integration Platforms Application Platforms Infrastructure Services Monitoring Services Network Backbone & Topology Directory Services File and Print Access Services Security & Access Management Development & Deployment Network Resource Management Messaging & Calendaring Routing & Security Architecture Mobile, Wireless & Telephony Storage Architecture
Section I The Business Process
9 An Enterprise can be Viewed as a Collection of Processes An Enterprise Inputs Outputs Resources
10 In fact, the essence of strategy revolves around processes § The business process movement has many parents, but none has been more influential than Michael E. Porter, who has given us the ideas that dominate today's thinking about strategy and the role of processes in achieving competitive advantage. § Competitors, Porter argued, would always try to copy your innovations and "best practices. " What they couldn't easily copy was a well integrated Value Chain in which every activity fit together to achieve a well thought out strategy. As Porter explained; "The essence of strategy is choosing to perform activities differently than rivals do. “ § Porter suggests that smart senior executives think in terms of processes. In effect, one strategic goal of the organization should be to create value chains and processes that are unique and that fit together to give the organization a clear competitive advantage that is difficult for rivals to duplicate. Limited Passenger Service Frequent & Reliable Departures Short, Point to Point Routes to 2 nd Airports Lean, Productive Ground & Gate Crews Very Low Ticket Prices High Aircraft Utilization Adapted from “What is Strategy, ” HBR, Porter 1996
11 But, what about the capability to Introduce and/or Change processes? Enterprise A* How fast? How much $? The ability to implement new processes and change existing processes in a fast, cost-effective manner facilitates competitive advantage and is the essence of ‘agility. ’
Section II The IT Environment
13 Issue #1: The n(n-1) Integration Complexity § Consider the n(n-1) integration problem. Many organizations face integration problems of some sort; perhaps because of a corporate merger, a new business alliance or just the need to interconnect existing systems. If n application systems must be directly interconnected, the process will produce n(n-1) interfaces. Note that each arrowhead represents an interface. § This set of 5 applications requires 20 interfaces; adding a 6 th application would require 10 new interfaces. § And to further increase complexity, one must modify code in each of the existing applications to include the new interfaces, generating substantial testing costs. § To reduce this cost and complexity, a solution that produces the minimum interfaces is required. Application 1 Application 4 (. NET) Application 2 Application 5 (J 2 EE) Application 3 Systems (n) # of Interfaces: n(n-1) 1 0 2 2 3 6 4 12 5 20 6 30
1 14 2 Issue #2: Redundant & Non-Reusable Programming § Over time, many enterprise application portfolios have increased in redundancy due to business combinations and business unit independence. As a result, many organizations deal with redundant applications – or applications with functions that can’t easily be reused. § Commonly, in decentralized organizations, business unit independence hinders any coordinated effort to create reusable functional assets or services. Collectively, this redundancy increases both cost and time to market to deploy new products or services, because changes have to be made in each application or system that is affected. This lack of reuse ultimately requires more resources – and often more time – to deliver new applications. Application Portfolio 1 1 Application 2 2 1 1 Application 3 Application 4
Section III SOA Introductory Concepts
16 Service-Oriented Architecture (SOA) is a multi-purpose buzzword A service-oriented architecture is a collection of services that communicate with each other. The services are self-contained and do not depend on the context or state of the other service. They work within a distributed systems architecture. Source: Is it an Enterprise Architecture? DMReview. com SOA is an architectural style whose goal is to achieve loose coupling among interacting software agents. A service is a unit of work done by a service provider to achieve desired end results for a service consumer. Both provider and consumer are roles played by software agents on behalf of their owners. Source: XML. com A service-oriented architecture is essentially a collection of services. These services communicate with each other. The communication can involve either simple data passing or it could involve two or more services coordinating some activity. Some means of connecting services to each other is needed. Source: service-architecture. com SOA refers to the re-engineering of IT systems and development that makes use of reusable chunks of software, aligned to business processes. Source: Diagonal Integrators SOA is one of the most popular architectural paradigms today, but without any standardized reference model. It is an architecture that provides seamless Enterprise Information Integration between loosely coupled distributed applications or services over the network. Source: ASP Alliance Is it an Application Architecture? Is it Software Architecture? Is it an Approach? Is it a Framework? Is it a Reference Model? In computing, the term Service-Oriented Architecture (SOA) expresses a perspective of software architecture that defines the use of services to support the requirements of software users. In a SOA environment, nodes on a network[1] make resources available to other participants in the network as independent services that the participants access in a standardized way. Most definitions of SOA identify the use of Web services (i. e. using SOAP or REST) in its implementation. However, one can implement SOA using any service-based technology. Source: http: //en. wikipedia. org/wiki/Serviceoriented_architecture Service-oriented architecture (SOA) is an evolution of distributed computing based on the request/reply design paradigm for synchronous and asynchronous applications. Source: Javaworld. com Service-oriented architecture (SOA) is a design methodology aimed at maximizing the reuse of application-neutral services to increase IT adaptability and efficiency. Source: http: //dev 2 dev. bea. com/soa/ SOA is an architectural style for building software applications that use services available in a network such as the web. It promotes loose coupling between software components so that they can be reused. Applications in SOA are built based on services. Source: Sun. com
17 Basic Concept: The Service Definition of a Service: A service is a unit of logic expressed in software that is designed for re-use by other software elements in different execution contexts. Service Interface Service Content Provides service identification, definition of parameters, and conventions concerning passing the service results back to the consumer Service content provides or encapsulates logic such as a business process, a technical feature, a stateless computation, etc…
1 2 18 3 Fundamental SOA consists of services, descriptions & messages 3 Services Communicate Through Messaging Process Step Service Encapsulation service § Messages are “independent units of communication” which need to be outfitted with enough intelligence to self-govern their parts of processing logic. § Similar to services, messages must be autonomous since after a service sends a message on its way, it loses control of what happens to the message thereafter. Service A sub-process Service B Self-governing message PROCESS service Service Composition 1 Services Encapsulate Logic service description for Service B § In SOA, units of logic are known as services. 2 § To retain their independence, services encapsulate logic within a distinct context. This context can be specific to a business task or some other logical grouping. § In SOA, services are aware of each other through the use of service descriptions. § The concern addressed by a service can be large or small. Therefore, the size and scope of the logic represented by the service can vary. § A service description establishes the name of the service and the data expected and returned by the service. § A collective is composed of several services. § The manner is which services use service descriptions results in a relationship classified as loosely coupled. Services Relate Through Service Descriptions
19 The Nature of a Service § A service can be a simple business capability: § get. Stock. Quote § get. Customer. Address § check. Credit. Rating § A service can be a complex business transaction: § open. Account: § verify. Customer. Identity § create. Customer. Account § commit. Inventory § sell. Covered. Option § schedule. Delivery § A service can be a system service: § log. Message. In § authenticate. User § This may seem like an artificial distinction of services. § The distinction is made to help quantify the level of granularity. § Services may be low-level (i. e. , fine-grained) or complex high-level (coarse-grained) functions and there are tradeoffs in: § § Performance Flexibility Maintainability Reuse § The level of granularity is a statement of a service’s functional richness. Adapted from “Migrating to a Service-Oriented Architecture, ” IBM, 2005
20 “Granularity” The term “granularity” is most commonly used to communicate the level of (or absence of) detail associated with some aspect of software program design. Within a service, different forms of granularity exist, all of which can be impacted by how service-orientation design principles are applied. Functional Granularity refers to the potential breadth of the service’s functional scope. For example, “Consolidate Invoices” is a coarse grained service. Data Granularity refers to the quantity of data a service needs to exchange in order to carry out its function. There has been a tendency for services implemented as Web Services to exchange document-centric messages – messages containing entire information sets or business documents. Constraint Granularity refers to the amount of detail with which a particular constraint is expressed. The schema or data model representing the structure of the information being exchanged by a service can define a series of specific validation constraints (data type, data length, data format, allowed values, etc…) for a give value and would represent a fine-grained constraint as opposed to a coarse-grained level of constraint granularity that would permit a range of values with no predefined length or formal restrictions. Consolidate Invoices § Get Invoice § Get Header § Retrieve PO Records § Perform Calculations § View Client History A fine-grained service will have less work to do than a coarse grained service. Adapted from “ SOA: Principles of Service Design, ” Erl, 2007
21 These Design Issues Require (Service-Oriented) Principles How should the relationship between services be defined? How should services be designed? Service A Service B Self-governing message How should service descriptions be designed? service description for Service B How should messages be designed?
22 The Service-Orientation Design Paradigm & Principles § a design paradigm is an approach to designing solution logic. § when building distributed solution logic, design approaches revolve around a software engineering theory known as the "separation of concerns” which states that a larger problem is more effectively solved when decomposed into a set of smaller problems or concerns. This gives us the option of partitioning solution logic into capabilities, each designed to solve an individual concern. Related capabilities can be grouped into units of solution logic. § The fundamental benefit to solving problems this way is that a number of the solution logic units can be designed to solve immediate concerns while still remaining agnostic to the greater problem. This provides the constant opportunity for us to reutilize the capabilities within those units to solve other problems as well. Service Oriented Design Principles: 1. Standardized Service Contract 2. Service Loose Coupling 3. Service Abstraction 4. Service Reusability 5. Service Autonomy 6. Service Statelessness 7. Service Composability 8. Service Discoverability § What distinguishes service-orientation is the manner in which it carries out the separation of concerns and how it shapes the individual units of solution logic. Applying service-orientation to a meaningful extent results in solution logic that can be safely classified as "service-oriented" and units that qualify as "services. " To understand exactly what that means requires an appreciation of the strategic goals of service-oriented computing combined with knowledge of the following service-orientation design principles: Adapted from “ SOA: Principles of Service Design, ” Erl, 2007
23 Principle #1: Standardized Service Contract "Services within the same service inventory are in compliance with the same contract design standards. " Services express their purpose and capabilities via a service contract. The Standardized Service Contract design principle is perhaps the most fundamental part of service-orientation in that it essentially requires that specific considerations be taken into account when designing a service’s public technical interface and assessing the nature and quantity of content that will be published as part of a service’s official contract. A great deal of emphasis is placed on specific aspects of contract design, including the manner in which services express functionality, how data types and data models are defined, and how policies are asserted and attached. There is a constant focus on ensuring that service contracts are both optimized, appropriately granular, and standardized to ensure that the endpoints established by services are consistent, reliable, and governable. WSDL <definitions> <types> <message> <parts> WS Policy <Policy> XML Schema <schema> <Exactly. One> <All> <element> <complex type> assertions… <port. Type> Figure: Using Web service contract documents (WSDL, XML schema, and WS-Policy definitions) as an example, this illustration highlights the areas that are typically affected by the application of this design principle. Adapted from “ SOA: Principles of Service Design, ” Erl, 2007
24 Key Concept: The Service Contract Definition: A Service Contract establishes the terms of engagement, providing technical constraints and requirements as well as any semantic information the service owner wishes to make public Historical Context: In the past, technical contracts have commonly been represented by a form of technical interface known as the API. The Interface Definition Language (IDL) and Abstract Syntax Notation (ASN. 1) were frequently used to express technical contracts for remote invocation frameworks such as those based on Remote Procedure Calls (RPC). Web Services: established a non-proprietary distributed communications framework that introduced the Web Services Description Language (WSDL) as the core part of the service contract. The XML schema language is used to define the data model for messages exchanged via Web services and the WS-Policy language facilitates policy assertion definition and attachment to various parts of the WSDL Service Contract Technical Web Service Contract WSDL XML Schema WS Policy SLA Figure: A Web Service can be comprised of the following service description documents: WSDL Definition, XML Schema Definition and WS Policy Description. The term “technical service contract” is used simply to refer to service description documents that are programmatically consumed at runtime. Note that SLAs and other human consumable service description documents can also be part of the service.
25 Principle #2: Service Loose Coupling "Service contracts impose low consumer coupling requirements and are themselves decoupled from their surrounding environment. " Coupling refers to a connection or relationship between two things. A measure of coupling is comparable to a level of dependency. This principle advocates the creation of a specific type of relationship within and outside of service boundaries, with a constant emphasis on reducing (“loosening”) dependencies between the service contract, its implementation, and its service consumers. The principle of Service Loose Coupling promotes the independent design and evolution of a service’s logic and implementation while still guaranteeing baseline interoperability with consumers that have come to rely on the service’s capabilities. There are numerous types of coupling involved in the design of a service, each of which can impact the content and granularity of its contract. Achieving the appropriate level of coupling requires that practical considerations be balanced against various service design preferences.
26 Principle #3: Service Abstraction Service contracts only contain essential information and information about services is limited to what is published in service contracts. Abstraction ties into many aspects of service-orientation. On a fundamental level, this principle emphasizes the need to hide as much of the underlying details of a service as possible. Doing so directly enables and preserves the previously described loosely coupled relationship. Service Abstraction also plays a significant role in the positioning and design of service compositions. Various forms of meta data come into the picture when assessing appropriate abstraction levels. The extent of abstraction applied can affect service contract granularity and can further influence the ultimate cost and effort of governing the service.
27 Principle #4: Service Reusability Services contain and express agnostic logic and can be positioned as reusable enterprise resources. Reuse is strongly emphasized within serviceorientation; so much so, that it becomes a core part of typical service analysis and design processes, and also forms the basis for key service models. The advent of mature, nonproprietary service technology has provided the opportunity to maximize the reuse potential of multi-purpose logic on an unprecedented level. The principle of Service Reusability emphasizes the positioning of services as enterprise resources with agnostic functional contexts. Numerous design considerations are raised to ensure that individual service capabilities are appropriately defined in relation to an agnostic service context, and to guarantee that they can facilitate the necessary reuse requirements.
28 Principle #5: Service Autonomy "Services exercise a high level of control over their underlying runtime execution environment. " For services to carry out their capabilities consistently and reliably, their underlying solution logic needs to have a significant degree of control over its environment and resources. The principle of Service Autonomy supports the extent to which other design principles can be effectively realized in real world production environments by fostering design characteristics that increase a service’s reliability and behavioral predictability. This principle raises various issues that pertain to the design of service logic as well as the service’s actual implementation environment. Isolation levels and service normalization considerations are taken into account to achieve a suitable measure of autonomy, especially for reusable services that are frequently shared.
29 Principle #6: Service Statelessness "Services minimize resource consumption by deferring the management of state information when necessary. " The management of excessive state information can compromise the availability of a service and undermine its scalability potential. Services are therefore ideally designed to remain stateful only when required. Applying the principle of Service Statelessness requires that measures of realistically attainable statelessness be assessed, based on the adequacy of the surrounding technology architecture to provide state management delegation and deferral options.
30 Principle #7: Service Discoverability "Services are supplemented with communicative meta data by which they can be effectively discovered and interpreted. " For services to be positioned as IT assets with repeatable ROI they need to be easily identified and understood when opportunities for reuse present themselves. The service design therefore needs to take the “communications quality” of the service and its individual capabilities into account, regardless of whether a discovery mechanism (such as a service registry) is an immediate part of the environment.
31 Principle #8: Service Composability "Services are effective composition participants, regardless of the size and complexity of the composition. " As the sophistication of service-oriented solutions continues to grow, so does the complexity of underlying service composition configurations. The ability to effectively compose services is a critical requirement for achieving some of the most fundamental goals of service-oriented computing. Complex service compositions place demands on service design that need to be anticipated to avoid massive retro-fitting efforts. Services are expected to be capable of participating as effective composition members, regardless of whether they need to be immediately enlisted in a composition. The principle of Service Composability addresses this requirement by ensuring that a variety of considerations are taken into account.
32 Summary of Service-Orientation Principles § Loose Coupling: § Services maintain a relationship that minimizes dependencies and only requires that they retain an awareness of each other § vs. Tight-Coupling: the functionality of each component heavily depends on the functionality implemented by other components. Often such components cannot be used independently of the overall system. That is the design is component-based, but the components are not stand alone. § Service Contract: § Services adhere to a communications agreement, as defined collectively by one or more service descriptions and related documents § Autonomy: § Services have control over the logic they encapsulate § Abstraction: § Beyond what is described in the service contract, services hide logic from the outside world § Reusability: § Logic is divided into services with the intention of promoting reuse § Statelessness: § Services minimize retaining information specific to an activity § Discoverability: § Services are designed to be outwardly descriptive so that they can be found assessed via available discovery mechanisms § Composability: § Collections of services can be coordinated and assembled to form composite services
33 Service-Orientation & the Enterprise § Business Logic: is structured into processes that express business requirements § Application Logic: is an automated implementation of business logic organized into technology solutions § Services establish an abstraction layer wedged between traditional business & application layers. § Services are developed & deployed in proprietary environments, wherein they are individually responsible for the encapsulation of specific application logic. Business Process Layer Services Layer § From an IT perspective, this enterprise logic can be divided into 2 important halves: business logic and application logic Business Logic Application Layer § The collective logic (or processes) that defines and drives the enterprise is an ever-evolving entity constantly changing in response to external & internal influences Application A (. NET) Application B (J 2 EE) Application C (Legacy)
34 Business Processes & Services “Open account for customer” Business Process Presentation – user interface Business Process Orchestration Business Services Get customer details Locate account type Add account to customer Coarse Grained Service Orchestration (Process Orchestration ) Technical Services Locate customer record Check customer status Lookup account type table Retrieve account details Create Customer. Account record Fine Grained Adapted from ANZ Banking Group Australia
35 SOA & Web Services § SOA can be implemented without Web services, and Web services can be used for non-SOA (e. g. RPC) interactions. However, Web services delivers key standards for implementing SOA. § The WS-* family scales to meet integration challenges intra-enterprise (enterprise application integration [EAI]) and inter-enterprise (business to business [B 2 B]). § XML is an ideal candidate for loosely coupled inter-application data sharing. XML is not self-describing, but XML Schema can be be used to constrain message layout and content. SOA “The architecture” § § § Services architecture Service contract Message based Service directory Protocol independent Coarse grained & document centric § § § Web services specs WSDL SOAP & XML UDDI HTTP Doc literal binding § RPC interactions § Binary XML Web services “An Implementation” § Process orchestration (BPEL) You don't have SOA until you build/buy services and compose them to implement business functionality. Web Services is the stack of standard web technologies required at both consumer and provider ends to implement the pipe for shipping XML messages between them.
36 In theory, SOA does not equal Web Services but is there another model? is used to invoke operations defined by SOAP is accessed using Web Services describes serves as a registry for is accessed using enables discovery of UDDI Figure 1. Web Services Model WSDL SOA is often discussed in conjunction with Web services, but the 2 are not synonymous. In theory, SOA does not require Web services, and simply implementing Web services does not result in an SOA. However, Web services are the 1 st standard for service -oriented computing to gain the nearuniversal vendor support. By standardizing essential elements of SOA, Web services remove the risk of having to be on a particular technology (e. g. , CORBA). is used to invoke operations defined by ? is accessed using Enterprise Services describes serves as a registry for is accessed using enables discovery of ? Figure 2. ? Model ?
37 1 st and 2 nd Generation SOA 1 st generation SOA, mostly inspired by the initial set of web services, defined SOA as an architecture modeled around 3 basic components: § service requester FIND: Service Registry PUBLISH Discover & retrieve WSDL § service provider § service registry 1 st generation web services standards: § WSDL described the service § SOAP provided the messaging format § UDDI provided the standardized service registry format 2 nd generation SOA added: § WS-* specifications (extension) § WS-BPEL supported the interest in applying service-orientation concepts to the world of business analysis. Service Requestor BIND & EXECUTE Service Provider
38 Contemporary Service Oriented Architecture Reference Model Corporate Network Enterprise Service Business Process Modeling Adapter Presentation Services SOA Repository SOA App Testing SOA Governance § Portal Services § Device Services § Messaging Services § Security Services § Translation Services Data Services § Data Federation § ETL § Metadata Management § Data Archiving § Backup & Recovery Workflow Engine In House Apps Adapter SOA Registry Package Apps Adapter Service Broker Collab’n Apps Infrastructure Services Software Development Modeling Tools Programming Tools App Servers DBMS CM & Lifecycle Tools Testing Tools § Identity & Authentication § Message Management § System Management § Security Management § Resilience & Recovery § Provisioning § Federation Services Adapter SOA Supervisor BI Apps & Services Source: Hurwitz Group, 2006
39 2 Key Advantages of SOA: easier logic evolution & state management § SOA establishes a loosely-coupled relationship between units of processing encapsulated as services. This allows the logic within each service boundary to be updated and evolved independently of existing service requestors, as long as the original service contract is preserved. logic Service B Service A logic § SOA promotes the standardization of XML data representation throughout solution environments. Further, service statelessness is emphasized by deferring state management to the message level. This maximizes reuse, availability and scalability of service logic but also provides a standardized state management approach. Self-governing message service description for Service B
40 Comparing Previous Architectures to Web Services § Compared to Web Services, CORBA solutions: § Are nearly as capable for cross-platform and cross-language development § Are harder to understand because CORBA relies on IDL to translate data § Can handle higher transaction loads because they keep a persistent connection § Compared to Web Services, RMI solutions: § Lock you into a purely Java solution on both the client and server § Can be somewhat more difficult to deploy because of network port considerations § Can handle higher transaction loads because RMI keeps a persistent connection between clients and servers at the expense of servicing fewer clients per server § In a Java-only trusted environment, RMI will perform faster than XML-based Web Services because of the reduced work in getting the data into a wire-friendly format § Compared to Web Services, DCOM solutions: § Are nearly as capable for Microsoft cross-language development but lock you into Microsoft. § Compared to Web Services, CGI solutions: § Are more difficult to find because of no directory service § Are more difficult to write clients for without a well-documented service-specific API to rely on § Are more difficult to interact with because there’s no accepted data interchange format. § Compared to Web Services, Servlet solutions: § Can only be written in Java § Lack a service directory § Lack an interface specification explaining how to communicate with them; no accepted data interchange format
41 Distributed Internet Architecture vs. Service Oriented Architecture Category Distributed Internet Architecture Service-Oriented Architecture § Tightly Coupled: at design time, the expected interaction § Inter-Component Communication: DIA promotes the use of § WS-Security Framework: emphasize the placement of security logic onto the § Maintaining component-based applications involves keeping track of Technology § XML data representation and the Web Services technology platform § Traditional delegation and impersonation approaches as well as HTTP Application Processing §Inter-Service Communication: Message-based communication that involves § There is no governance of the technologies used by DIAs (e. g. , Application Logic § Loosely Coupled: SOA still reply on components but the use of Web Services § Require additional runtime administration since problems with messaging components will have with others is taken into account – so much so that actual references to other physical components can be embedded in code. It is efficient in that little processing is wasted in trying to locate a required component but the embedded coupling leads to a tightly coupled component network. § Parameter-based Data Exchange: components provide methods that, once invoked, send and receive parameter data. § Re-use: emphasized but rarely achieved due to tight-coupling. proprietary communication protocols such as DCOM and vendor implementations of CORBA for remote data exchange § supports the creation of stateful and stateless components that interact with synchronous data exchanges (asynchronous supported by some platforms but rarely used). components, server-side scripts, raw web technologies such as HTML and HTTP) encryption Security Administration individual component instances, tracing local and remote communication problems, monitoring server resource demands and standard DBA tasks. § DIA introduces the Web Server as the official first point of contact for clients so is must therefore be designed for scalability. § RPC-based data exchange generally requires a response from an initiating component and an exception handling routine is employed. (i. e. , standardized interface and open communications framework) supports a composition model, allowing individual services to participate in aggregate assemblies. § Document-Style Data Exchange: web services communicate with SOAP messages which rely primarily on document-style messages which are structured to be as self-sufficient (meta information, processing instructions and policy rules) as possible which results in less individual transactions. § Re-use: fosters re-use and cross-application interoperability by promoting the creation of solution-agnostic services. the serialization, transmission an de-serialization of SOAP messages containing XML payloads. (Despite improved parsers and hardware accelerators, SOAP still lags RPC communication. ) Document and message modeling conventions and the strategic placement of validation logic are important factors that shape the transport layer of SOA. §Although synchronous communication is supported, asynchronous patterns are encouraged, as they help minimize communication. § Further supporting the statelessness of services are various context management options that can be employed, such as WS-Coordination and WS-BPEL messaging level. SOAP messages provide header blocks in which security logic can be stored which helps to preserve individual autonomy and loose coupling between services as well as the extent to which a service can remain fully stateless. frameworks (especially when working with asynchronous exchange patterns) can more easily go undetected than with RPC-based data exchanges since so many variations exist as to how messages can be interchanged. § WS-* extensions for messaging frameworks have yet to reach maturity § UDDI helps with resource management and service description
Section IV SOA Implementation Considerations
43 Where are We? An SOA Maturity Model Collaborative services creating dynamic, collaborative business relationships Services directly implement business service capability Service as a process creates modular units of business process Service increases loose coupling and separation of concerns Data integration, client neutrality, shared internal services Federated Business Services Business Process Improvement Application Integration Technical Applications Adapted from CBDi
44 What’s Our Approach? Top-Down, Bottom-Up, Middle-out, Hybrid? “Top down” and “bottom up” considerations need to be balanced. Governance • • Technical Ownership Executive Business Ownership Architecture • • Principles Patterns Architecture Skills Funding Repository Top down • Measurement Management Rewards Business SOA Technology Enablers Proof of Concepts Simple Web Services Select SOA tools Bottom up Design and Development Skills
work_stream: Business Services ESTR Guidelines: Tips for Smarter Service Design The coarse- and fine-grained trade-off is a matter of latency and usability. At the end of the day, you should move to a good SOA, exposing the right services that do the right things, and not be as concerned about granularity. Services that implement fine-grained interfaces and that are meant for local invocation will work well. Moreover, services that implement fine-grained interfaces, that are meant for distributed invocation, and that are on a low-latency network will also work well. No. 01 02 03 04 05 06 Tip Description Design services to be shared The value of a service is magnified by the value of the relationships enabled. Being shared does not mean the code is shared; the service is shared. One of the important advantages of a services-based model is that the provider of a service is not concerned with the consumer's platform and the consumer does not have to install and maintain software. Services enable the acquisition of new functionality without having to deploy and maintain new applications. Services have a clear purpose The business value of services to consumers of those services must be clear and unambiguous. To maximize the value of services, it is necessary to understand the core competencies your organization provides to others. When this business value can be articulated clearly, it defines the requirements for services that are useful to others in your value chain. Services are discoverable and support introspection To share services, the producer of a service must be able to publish it in a form the consumer of the service can find and bind to dynamically. The consumer must be able to discern how to use the service without having to talk person to the producer of the service. The conversation on how to use the service is ideally machine to machine. Services are designed to be loosely coupled Services are intended live in a loosely coupled environment and should use other services to perform common clearly defined tasks (for example, authentication or reporting). The value of services is magnified by their reuse and further magnified by their ability to be combined with other services to create new services. As services are typically owned by multiple entities, they need to be loosely coupled to allow each one to change and evolve independently of the others. Services plug into a framework Once a service has been discovered, it needs a framework that provides other common services and loose coupling. While services may be created without an SOA, they need an SOA to operate in. SOAs by their nature are federated, as they need to interact in a loosely coupled manner. A service has a well-defined use policy/contract It is important to realize that in a services model both the consumer and the producer of a service need the ability to set use polices. The consumer and producer of a service define policies around security, availability, reliability, and error and exception handling. 46
Common Tangible Benefits of SOA Many of the benefits promised by SOA do not manifest themselves until the use of service-oriented principles becomes established within an enterprise. As a result, there are few short-term benefits § Improved Integration (and intrinsic interoperability) § Because of the vendor-neutral communications framework established by Web Services driven SOA, the potential exists for enterprises to implement highly standardized service descriptions and message structures § State of Federation, where previously isolated environment now can interoperate without requiring expensive and fragile point-to-point solutions § Inherent Reuse § Building services to be inherently reusable results in a moderately increased development effort and requires design standards. § Subsequently leveraging reuse within services lowers the cost and building service-oriented solutions § Streamlined Architectures & Solutions § The concept of composition can lead to highly optimized automation environments: § Assembly of service collections into aggregate services § The WS* platform is based on the principle of composability § Leveraging the Legacy Investment § Industry-wide acceptance of the Web Services technology set has spawned a large adapter market § Best of Breed Alternatives § Because SOA establishes a vendor-neutral communications framework, IT is not longer restricted to a single proprietary development and/or middleware platform § Organizational Agility § How building blocks can be realized and maintained within existing financial and cultural constraints ultimately determines the agility of the organization as a whole 47
48 Common Pitfalls of Adopting SOA § Building service-oriented architectures like traditional distributed architectures § Problems: § proliferation of RPC-style service descriptions (leading to increased volumes of fine-grained message exchanges) § inhibiting the adoption of features provided by WS-* specifications § Further entrenchment of synchronous communication patterns § Creation of hybrid or non-standardized services § Not creating a transition plan § Migration needs to happen at the technical, process and organization levels to avoid ad-hoc adoption § Not standardizing SOA § Like any other architecture, SOA requires the creation and enforcement of design standards § Failing to create an XML foundation architecture § SOA requires standardizing how core XML technologies are used to represent, validate and process corporate data § Failing to account for SOA performance requirements § As message-based communication increases, processing latency can be an issue § Lack of proper SOA security model § Secure Sockets Layer (SSL) is not the technology of choice for SOA; the need for message-level security implies that the WS-Security Framework is optimal § Failure to understandards organizations § Web Services Interoperability (WS-I): Basic Profile and Basic Security Profile
49 Performance Issues § Message-based communication in SOAs can, in fact, increase performance requirements when compared to RPC-style communication within traditional distributed architecture § XML processing-related performance challenges § Web services security measures, such as encryption and digital signing, add new layers of processing to both the senders and recipients of messages § Need to test the message processing capabilities of your environments § Stress testing the vendor supplied processors (for XML, XSLT, SOAP, etc. . ) § Considering alternative processors, accelerators or other types of technology: § XML-binary Optimized Packaging (XOP) § SOA Message Transmission Optimization Mechanism (MTOM) § Performance is one of the reasons why: § Coarse-grained service interfaces and asynchronous messaging are emphasized when building Web Services
50 Best Practice: Create a Services Blueprint for Transformation Partner & Supplier Interaction Fund Accounting Cash Management Process Information Requests Pricing • Price/Value Investments • Correct Pricing Error Securities Accounting • Setup/Maintain Settlement Analysis & Product Development Performance Analysis • Product/Service Success Analytics Service Development • R&D • Product Lifecycle Account • Setup/Maintain DC/DB Plan • Setup/Maintain Trust Manage Information Requests • Provide Information • Provide Personalized Payment • Manage Loans • Manage Trust Assets • Manage Trust Income & Disbursements • Process Corporate Actions • Withhold Taxes • Purge/Archive Records • Manage Client Payments • Prepare Excess Refund • Prepare Pass-Through Dividend • Manage Brokerage Orders External Advisors Performance Data Client Prepare Client Transactions • Prepare Purchase • Prepare Redemption • Prepare Exchange • Prepare Buy • Prepare Sell • Exercise Options • Prepare Contribution • Prepare Withdrawal • Prepare Rollover • Perform Adjustments • Administer Installment Setup • Administer Annuitization Setup • Administer Loan • Prepare Asset/ Account Transfer • Prepare Plan Level Transfer • Prepare 1035 Exchange • Terminate Person • Prepare Death Claim • Perform Market Call Center/IVR Customer Service • Call Center Services • Customer Lifecycle • Customer Segment Management • Reconcile Checks • Reconcile Client Accounts • Reconcile Transfer Agency Accounts • Reconcile Custody Bank Accounts • Reconcile Omnibus Accounts Compliance Sales Force Automation Investment Strategies Management • Monitor Investment Compliance • Monitor Client Compliance • Audit Dividend & Capital Gain Disbursements Client Control Reporting • Process As-of Transactions • Provide Tax Services Money Movement • Move Money Inventory Management • Manage Literature Inventory • Fulfill Literature Requests Retirement Client Brokerage Client Web Endowment Client Investment Management • Campaign Management • Contact Management • Sales Goal Performance • Manage Portfolios • Replicate Indexes • Manage Order Routing and Execution • Monitor Performance Kiosk/POS Research/Analysis • Create/Modify Products/Services • Educate Client • Prepare Communications Client Management/Dashboard Management & Operations • Account • Reconciliation Transaction Clearinghouses Person • Setup/Maintain • Rebalance Assets • Calculate Benefits • Convert New Plan • Bill Fees • Process Credit/Margin • Calculate Annuity Payments • Administer Annuitization Customer Segments Marketing Manage Accounts Payment Lending • Perform Clearing & Channels • Analyze/Understand Account Management Notifications • Manage Assets • Manage Account Balance • Administer Installment • Conduct Securities • Create Financial Plan • Manage Financial Plan • Generate Reports • Generate Statements • Generate Confirm/ Process Client Transactions Trust Accounting Customer Relationship Management Financial Planning • Manage Cash Brokers Advisory Services Record Keeping Trust Client Mobile Financial Management • Perform Corporate Budgeting • Provide Executive Information • Execute Monthly/Yearly Financials • Perform AP/AR • Issue Payroll • Track Assets • Prepare Compliance Reporting Human Resources Fax Defined Contribution Client Paper Defined Benefit Client • Hire/Retain/Release Employees • Provide Career Management • Provide Work/Life Initiatives • Prepare Compliance Reporting
51 Best Practice: Create an ESA Reference Model Business Architecture & Business Process Models Enterprise Business Services Business Applications Enterprise Packaged Applications Business Process Services Business Services Information Assets Business Services Domain 1 Domain 2 Customer Finance Orders Technology Shared Services Enterprise Presentation Services Enterprise Application Services Information Services Data Infrastructure Client Services Core Application Services Personalization Services Business Intelligence Business Process Integration Data Access Services Digital Asset Management Enterprise Platforms Integration Platforms Application Platforms Infrastructure Services Monitoring Services Network Backbone & Topology Directory Services File and Print Access Services Security & Access Management Development & Deployment Network Resource Management Messaging & Calendaring Routing & Security Architecture Mobile, Wireless & Telephony Storage Architecture
52 Best Practice: Create & Publish an SOA Standards Stack Layer Standard Knowledge definition UML Choreography BPEL WSRP Service invocation SOAP, WSIF Security WS-Security – Liberty profile supports this (including SAML and XACML) Service description WSDL Schema of the syntax Provider UBL Presentation Consumer Generic vocabulary XML Schema, Relax. NG, DTD, ASN. 1, RDF Schema, IFX, LIXI Document syntax XML, EDI, IIOP, BER encoding Messaging envelope SOAP, S/MIME, eb. MS, WS-Reliability XML transformation XSLT Data queries XPATH, XQUERY, XBRL Single standard desirable Multiple standards acceptable
53 Best Practice: Define Registry/Repository Use Cases
54 Considerations when Implementing Service-Oriented Architecture § Service identification: § What is a service? § What is the business functionality to be provided by a given service? § What is the optimal granularity of the service? § Service domain definition: § How should services be grouped together into logical domains? § Service packaging: § How will existing functionality within, say, legacy mainframe systems be re-engineered or wrapped into reusable services? § Service orchestration: § How are composite services orchestrated? § Service location: § Where should a service be located within the enterprise? § Service routing: § How are requests from service consumers routed to the appropriate service and/or service domain? § Service Publication and Discovery: § How should the services be catalogued so that business and IT users can identify and possible reuse the services in their applications and processes? § Service governance: § How will the enterprise exercise governance processes to administer and maintain services? § What standards will be defined for messaging, choreography, etc. , that can be adopted consistently within the organization. § Service Development & Deployment : § What modeling, design, development & deployment platforms to be used? § Service Integration Testing : § What is the testing strategy for loosely coupled components? § What testing harnesses or tools will be used? § Service Performance : § How to ensure throughput, availability, reliability? § Service Versioning & Release Management: § What are the procedures for service versioning, release management & migration
Section VI SOA POC: Insurance Claim Processing
56 SOA POC: Business Scenario 1. A customer enters a claim via the website / portal 2. The entry is validated against a customer information system (service) 3. A valid entry is registered – customer has valid policy (service) 4. Customer receives acknowledgement of claim registration (service) 5. Claim checked against insurance policy (coverage, amount, provider) 6. Claim approved or rejected or requires clarification 7. Customer notified of approval or rejection (notification service) 8. If Approve or Reject, process to logical end 9. Send payment advice to Accounts Payable 10. Update customer claim processed (service) 11. Notify customer -------------------------------§ Customer can query status of claim (service)
57 SOA POC: Business Process Swim Lane Diagram
58 SOA POC: Business Process Model (Level 0)
59 SOA POC: Business Process Model (Level 1)
60 SOA POC: Process Choreography
61 SOA POC: Service Interface Definition (WSDL)
62 SOA POC: Schema Definition
63 SOA POC: Service Interaction Diagram
64 Example: SOA Implementation Project Approach Phase Requirements Gathering & Analysis Activity Role Artifacts Current & Future state problem definition BA Requirements Functional description of requirements BA Use Cases Business Process Modeling BA Business Process Model, Event Based Sequence Diagrams (“Swim-Lane” Diagrams) ( ) BA / Architect Final Business Process Model, Event Based Sequence Diagrams (“Swim-Lane” Diagrams), Functional Specs Business Process Design Detailed Business Process Modeling & Simulation Business Process Technical Design Business Process Choreography Design Architect/Developer BPEL, Data Model, UI Model, Process Test Use Cases , Functional/Technical Specs (WSDL) Business Process Implementation Coarse-Grained Service Identification, Design & Development Architect/Developer Process & Service Interaction Diagrams, Revised Data Model, Service Test Use Cases, Functional/Technical Specs (WSDL) Service Implementation Fine-Grained Services Identification, Design & Development Architect/Developer Class Diagrams, Final-Data Model, Service Test Use Cases (WSDL)
65 SOA POC: High Level Technical Architecture
66 SOA POC: Technology Landscape WBI Modeler & Monitors Process Choreographer (Web. Sphere Server Foundation) SOAP/HTTP, SOAP/JMS, EJB Web. Sphere MQ Broker (WBIMB) WMQ Applications Message flows Web Services (Java, . NET, Other)
Additional Resources
Liquid. Hub’s SOA Foundations Course for Managers: Concepts, Strategy and Technology § Lesson 1: Introduction § Contemporary Business and IT Challenges § Enterprise Architecture Concepts § Service Oriented Architecture Concepts § SOA Benefits § Lesson 2: The Evolution of SOA § SOA vs. Past Architectures § E. g. , SOA vs. Client Server Architecture § Lesson 3: The Road To SOA § SOA Enterprise Strategy § SOA Enterprise Governance § Lesson 4: The SOA Delivery Lifecycle § SOA SDLC Phases § SOA Templates § SOA Project Roles § Lesson 5: SOA Project Management § Resource Planning § Migration Planning § Elevation Planning § Integration Planning § Lesson 6: Web Services Fundamentals § XML Overview § SOAP Overview § UDDI Overview § WS* Overview § Lesson 7: Key SOA Technologies § Business Process Management Suite § Enterprise Services Bus § Repository / Registry § Lesson 8: Case Studies § SOA Strategy: HBR Peachtree Healthcare § SOA Implementation: LH IBM w. S 68
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