SOA Design Patterns

DESCRIPTION

"SOA Design Patterns is an important contribution to the literature and practice of building and delivering quality software-intensive systems." This book series is further supported by a series of resources sites, including soabooks, soaspecs, soapatterns, soamag, and soaposters. Table of Contents Foreword...xxxvii CHAPTER 1: Introduction...1 1.1 Objectives of this Book ... 4 1.2 Who this Book is For ... 4 1.3 What this Book Does Not Cover... 4 Topics Covered by Other Books ...4 Web Service and REST Service Design Patterns ... 5 SOA Standardization Efforts... 5 1.4 Recommended Reading ... 6 1.5 How this Book is Organized... 7 Part I: Fundamentals... 8 Part II: Service Inventory Design Patterns... 8 Part III: Service Design Patterns . . 8 Part IV: Service Composition Design Patterns . . 9 Part V: Supplemental. . . 10 Part VI: Appendices . . . 10 1.6 Symbols, Figures, Style Conventions . . . 11 Symbol Legend . . . 11 How Color is Used 11 Data Flow and Directionality Conventions . . 11 Pattern Documentation Conventions . 11 1.7 Additional Information 11 Updates, Errata, and Resources (www.soabooks.com) . . . . 11 Visio Stencil (www.soabooks.com) . 12 Community Patterns Site (www.soapatterns.org) . . . . . 12 Master Glossary (www.soaglossary.com) 12 Supplementary Posters (www.soaposters.com) 12 The SOA Magazine (www.soamag.com) 12 Referenced Specifications (www.soaspecs.com). . . . . 12 Notification Service 13 Contact the Author 13 CHAPTER 2: Case StudyBackground . 15 2.1 Case #1 Background: Cutit Saws Ltd 17 History 18 Technical Infrastructure and Automation Environment . 18 Business Goals and Obstacles. . 18 2.2 Case #2 Background: Alleywood Lumber Company . 19 History 19 Technical Infrastructure and Automation Environment . 20 Business Goals and Obstacles. . 20 2.3 Case #3 Background: Forestry Regulatory Commission (FRC) . . 21 History 21 Technical Infrastructure and Automation Environment . 21 Business Goals and Obstacles. . 22 PART I: FUNDAMENTALS CHAPTER 3: Basic Terms and Concepts . . . . . 25 Purpose of this Introductory Chapter . . . 26 3.1 Architecture Fundamentals 26 A Classic Analogy for Architecture and Infrastructure . 27 Technology Architecture 27 Technology Infrastructure . 30 Software Program . 32 Relationship to Design Framework . 33 3.2 Service-Oriented Computing Fundamentals. . . . 35 Service-Oriented Computing . . . 35 Service-Orientation 36 Service-Oriented Architecture (SOA) . . . 37 Service . . . . . 37 Service Capability . 38 Service Consumer. 38 Service Composition . . . 40 Service Inventory. . 42 Service-Oriented Analysis. 43 Service Candidate. 44 3.3 Service Implementation Mediums . . . 44 Services as Components . 45 Services as Web Services 45 REST Services. . . . 46 CHAPTER 4: The Architecture of Service-Orientation . . 47 Purpose of this Introductory Chapter . . . 48 4.1 The Method of Service-Orientation 48 Principles of Service-Orientation. 48 Strategic Goals of Service-Oriented Computing. . . . . . 51 4.2 The Four Characteristics of SOA 52 Business-Driven . . 53 Vendor-Neutral . . . 54 Enterprise-Centric . 58 Composition-Centric . . . 59 4.3 The Four Common Types of SOA . 61 Service Architecture . . . 62 Information Hiding . . . . 64 Design Standards . 64 Service Contracts . 65 Service Agents . . . 67 Service Capabilities . . . 68 Service Composition Architecture . 68 Nested Compositions . . 72 Task Services and Alternative Compositions . 73 Compositions and Infrastructure. 74 Service Inventory Architecture . . 74 Service-Oriented Enterprise Architecture 76 Architecture Types and Scope . . 77 Architecture Types and Inheritance 77 Other Forms of Service-Oriented Architecture . 78 Inter-Business Service Architecture . . 78 Service-Oriented Community Architecture . . 78 4.4 The End Result of Service-Orientation . . 79 CHAPTER 5: Understanding SOA Design Patterns . 85 Purpose of this Introductory Chapter . . . 86 5.1 Fundamental Terminology. 86 What's a Design Pattern? . 86 What's a Compound Pattern? . . . 88 What's a Design Pattern Language? . 88 What's a Design Pattern Catalog? . . . 89 5.2 Historical Influences 89 Alexander's Pattern Language . . 90 Object-Oriented Patterns . 91 Software Architecture Patterns . . 92 Enterprise Application Architecture Patterns . . 93 EAI Patterns . 93 SOA Patterns . . . . 94 5.3 Pattern Notation . 95 Pattern Symbols . . 95 Pattern Figures . . . 96 Pattern Application Sequence Figures 96 Pattern Relationship Figures. 96 Compound Pattern Hierarchy Figures 99 Capitalization. . . . 100 Page Number References. 100 5.4 Pattern Profiles . 100 Requirement . . . . 101 Icon . 101 Summary . . 102 Problem . . . . 102 Solution . . . . 102 Application . 103 Impacts . . . . 103 Relationships. . . . 103 Case Study Example. . 103 5.5 Patterns with Common Characteristics. 104 Canonical Patterns . . . 104 Centralization Patterns 105 5.6 Key Design Considerations . . 106 "Enterprise" vs. "Enterprise-wide" . . 106 Design Patterns and Design Principles 106 Design Patterns and Design Granularity . . 107 Measures of Design Pattern Application . . 108 PART II: SERVICE INVENTORY DESIGN PATTERNS CHAPTER 6: Foundational Inventory Patterns . . . 111 How Inventory Design Patterns Relate to SOA Design Characteristics . . 113 How Foundational Inventory and Service Patterns Relate . 114 How Case Studies are Used in this Chapter. . 114 6.1 Inventory Boundary Patterns . 114 Enterprise Inventory . 116 Problem . . . . 116 Solution . . . . 117 Application. . 118 Impacts . . . . 120 Relationships. . . . 121 Case Study Example. . 122 Domain Inventory . 123 Problem . . . . 123 Solution . . . . 124 Application. . 125 Impacts . . . . 126 Relationships. . . . 127 Case Study Example. . 128 6.2 Inventory Structure Patterns 130 Service Normalization. 131 Problem . . . . 131 Solution . . . . 132 Application. . 132 Impacts . . . . 133 Relationships. . . . 133 Case Study Example. . 135 Logic Centralization . 136 Problem . . . . 136 Solution . . . . 137 Application. . 137 Impacts . . . . 139 Relationships. . . . 140 Case Study Example. . 142 Service Layers 143 Problem . . . . 143 Solution . . . . 144 Application. . 145 Impacts . . . . 147 Relationships. . . . 147 Case Study Example. . 148 6.3 Inventory Standardization Patterns 149 Canonical Protocol 150 Problem . . . . 151 Solution . . . . 152 Application. . 153 Impacts . . . . 155 Relationships. . . . 155 Case Study Example. . 157 Canonical Schema 158 Problem . . . . 158 Solution . . . . 159 Application. . 159 Impacts . . . . 159 Relationships. . . . 160 Case Study Example. . 161 CHAPTER 7: Logical Inventory Layer Patterns . . . 163 Combining Layers 164 Business Logic and Utility Logic . . . 166 Agnostic Logic and Non-Agnostic Logic 166 Service Layers and Logic Types . . . 167 Utility Abstraction . 168 Problem . . . . 168 Solution . . . . 169 Application. . 170 Impacts . . . . 171 Relationships. . . . 171 Case Study Example. . 173 Entity Abstraction . 175 Problem . . . . 175 Solution . . . . 176 Application. . 176 Impacts . . . . 178 Relationships. . . . 178 Case Study Example. . 180 Process Abstraction . 182 Problem . . . . 182 Solution . . . . 183 Application. . 184 Impacts . . . . 185 Relationships. . . . 185 Case Study Example. . 187 CHAPTER 8: Inventory Centralization Patterns . . 191 Process Centralization 193 Problem . . . . 193 Solution . . . . 194 Application. . 195 Impacts . . . . 196 Relationships. . . . 197 Case Study Example. . 198 Schema Centralization 200 Problem . . . . 200 Solution . . . . 201 Application. . 202 Impacts . . . . 202 Relationships. . . . 203 Case Study Example. . 203 Policy Centralization . 207 Problems . . . 207 Solution . . . . 208 Application. . 209 Impacts . . . . 210 Relationships. . . . 211 Case Study Example. . 213 Rules Centralization . 216 Problem . . . . 216 Solution . . . . 217 Application. . 217 Impacts . . . . 218 Relationships. . . . 219 Case Study Example. . 222 CHAPTER 9: Inventory Implementation Patterns . 225 Dual Protocols 227 Problem . . . . 228 Solution . . . . 228 Application. . 228 Impacts . . . . 233 Relationships. . . . 234 Case Study Example. . 235 Canonical Resources 237 Problem . . . . 238 Solution . . . . 238 Application. . 239 Impacts . . . . 239 Relationships. . . . 239 Case Study Example. . 241 State Repository . . 242 Problem . . . . 242 Solution . . . . 243 Application. . 244 Impacts . . . . 244 Relationships. . . . 244 Case Study Example. . 246 Stateful Services . . 248 Problem . . . . 248 Solution . . . . 248 Application. . 250 Impacts . . . . 250 Relationships. . . . 250 Case Study Example. . 251 Service Grid . . 254 Problem . . . . 254 Solution . . . . 255 Application. . 256 Impacts . . . . 257 Relationships. . . . 258 Case Study Example. . 259 Inventory Endpoint 260 Problem . . . . 260 Solution . . . . 261 Application. . 262 Impacts . . . . 263 Relationships. . . . 263 Case Study Example. . 265 Cross-Domain Utility Layer 267 Problem . . . . 267 Solution . . . . 268 Application. . 269 Impacts . . . . 269 Relationships. . . . 270 Case Study Example. . 270 CHAPTER 10: Inventory Governance Patterns . . . 273 Canonical Expression. 275 Problem . . . . 275 Solution . . . . 275 Application. . 276 Impacts . . . . 277 Relationships. . . . 278 Case Study Example. . 279 Metadata Centralization . . . 280 Problem . . . . 280 Solution . . . . 281 Application. . 282 Impacts . . . . 283 Relationships. . . . 283 Case Study Example. . 284 Canonical Versioning 286 Problem . . . . 286 Solution . . . . 287 Application. . 287 Impacts . . . . 288 Relationships. . . . 288 Case Study Example. . 290 PART III: SERVICE DESIGN PATTERNS CHAPTER 11: Foundational Service Patterns . . . . 295 Case Study Background 297 11.1 Service Identification Patterns . 299 Functional Decomposition . 300 Problem . . . . 300 Solution . . . . 301 Application. . 302 Impacts . . . . 302 Relationships. . . . 303 Case Study Example. . 303 Service Encapsulation 305 Problem . . . . 305 Solution . . . . 306 Application. . 307 Impacts . . . . 309 Relationships. . . . 309 Case Study Example. . 310 11.2 Service Definition Patterns 311 Agnostic Context. . 312 Problem . . . . 313 Solution . . . . 314 Application. . 315 Impacts . . . . 315 Relationships. . . . 316 Case Study Example. . 317 Non-Agnostic Context 319 Problem . . . . 319 Solution . . . . 320 Application. . 321 Impacts . . . . 322 Relationships. . . . 322 Case Study Example. . 323 Agnostic Capability324 Problem . . . . 324 Solution . . . . 325 Application. . 326 Impacts . . . . 327 Relationships. . . . 327 Case Study Example. . 328 CHAPTER 12: Service Implementation Patterns. . 331 Service Faade . . . 333 Problem . . . . 333 Solution . . . . 334 Application. . 335 Impacts . . . . 341 Relationships. . . . 342 Case Study Example. . 343 Redundant Implementation 345 Problem . . . . 345 Solution . . . . 346 Application. . 346 Impacts . . . . 347 Relationships. . . . 348 Case Study Example. . 349 Service Data Replication . . 350 Problem . . . . 350 Solution . . . . 352 Application. . 353 Impacts . . . . 353 Relationships. . . . 353 Case Study Example. . 354 Partial State Deferral . 356 Problem . . . . 356 Solution . . . . 357 Application. . 358 Impacts . . . . 359 Relationships. . . . 359 Case Study Example. . 360 Partial Validation . . 362 Problem . . . . 362 Solution . . . . 363 Application. . 364 Impacts . . . . 364 Relationships. . . . 364 Case Study Example. . 365 UI Mediator. . . 366 Problem . . . . 366 Solution . . . . 367 Application. . 368 Impacts . . . . 369 Relationships. . . . 370 Case Study Example. . 370 CHAPTER 13: Service Security Patterns . . . 373 Case Study background 374 Exception Shielding . 376 Problem . . . . 376 Solution . . . . 377 Application. . 378 Impacts . . . . 379 Relationships. . . . 379 Case Study Example. . 380 Message Screening381 Problem . . . . 381 Solution . . . . 382 Application . 382 Impacts . . . . 384 Relationships. . . . 385 Case Study Example. . 385 Trusted Subsystem 387 Problem . . . . 387 Solution . . . . 388 Application. . 388 Impacts . . . . 391 Relationships. . . . 391 Case Study Example. . 392 Service Perimeter Guard 394 Problem . . . . 394 Solution . . . . 395 Application . 395 Impacts . . . . 396 Relationships. . . . 396 Case Study Example. . 397 CHAPTER 14: Service Contract Design Patterns . 399 Decoupled Contract . 401 Problem . . . . 401 Solution . . . . 402 Application. . 403 Impacts . . . . 405 Relationships. . . . 405 Case Study Example. . 407 Contract Centralization . 409 Problem . . . . 409 Solution . . . . 410 Application. . 410 Impacts . . . . 411 Relationships. . . . 411 Case Study Example. . 413 Contract Denormalization. . 414 Problem . . . . 414 Solution . . . . 415 Application. . 416 Impacts . . . . 417 Relationships. . . . 417 Case Study Example. . 418 Concurrent Contracts 421 Problem . . . . 421 Solution . . . . 422 Application. . 423 Impacts . . . . 425 Relationships. . . . 425 Case Study Example. . 426 Validation Abstraction 429 Problem . . . . 429 Solution . . . . 430 Application. . 431 Impacts . . . . 432 Relationships. . . . 432 Case Study Example. . 433 Chapter 15: Legacy Encapsulation Patterns . . . 439 Legacy Wrapper. . . 441 Problem . . . . 441 Solution . . . . 442 Application. . 443 Impacts . . . . 444 Relationships. . . . 444 Case Study Example. . 446 Multi-Channel Endpoint . . . 451 Problem . . . . 451 Solution . . . . 452 Application. . 453 Impacts . . . . 454 Relationships. . . . 454 Case Study Example. . 456 File Gateway . 457 Problem . . . . 457 Solution . . . . 458 Application. . 458 Impacts . . . . 459 Relationships. . . . 460 Case Study Example. . 461 CHAPTER 16: Service Governance Patterns. . . . . 463 Compatible Change465 Problem . . . . 465 Solution . . . . 466 Application. . 466 Impacts . . . . 469 Relationships. . . . 469 Case Study Example. . 470 Version Identification 472 Problem . . . . 472 Solution . . . . 473 Application. . 473 Impacts . . . . 474 Relationships. . . . 474 Case Study Example. . 475 Termination Notification . . . 478 Problem . . . . 478 Solution . . . . 479 Application. . 480 Impacts . . . . 480 Relationships. . . . 481 Case Study Example. . 481 Service Refactoring484 Problem . . . . 484 Solution . . . . 485 Application. . 485 Impacts . . . . 486 Relationships. . . . 486 Case Study Example. . 488 Service Decomposition . 489 Problem . . . . 489 Solution . . . . 491 Application. . 492 Impacts . . . . 492 Relationships. . . . 494 Case Study Example. . 495 Proxy Capability . . 497 Problem . . . . 497 Solution . . . . 498 Application. . 498 Impacts . . . . 500 Relationships. . . . 500 Case Study Example. . 501 Decomposed Capability . . . 504 Problem . . . . 504 Solution . . . . 506 Application. . 507 Impacts . . . . 507 Relationships. . . . 508 Case Study Example. . 508 Distributed Capability 510 Problem . . . . 510 Solution . . . . 511 Application. . 512 Impacts . . . . 513 Relationships. . . . 513 Case Study Example. . 514 PART IV: SERVICE COMPOSITION DESIGN PATTERNS CHAPTER 17: Capability Composition Patterns . . 519 Capability Composition . . . 521 Problem . . . . 521 Solution . . . . 521 Application. . 523 Impacts . . . . 523 Relationships. . . . 523 Case Study Example. . 524 Capability Recomposition . 526 Problem . . . . 526 Solution . . . . 527 Application. . 527 Impacts . . . . 527 Relationships. . . . 529 Case Study Example. . 530 CHAPTER 18: Service Messaging Patterns. . 531 Service Messaging 533 Problem . . . . 533 Solution . . . . 533 Application. . 534 Impacts . . . . 534 Relationships. . . . 535 Case Study Example. . 536 Messaging Metadata 538 Problem . . . . 538 Solution . . . . 538 Application. . 539 Impacts . . . . 540 Relationships. . . . 541 Case Study Example. . 542 Service Agent 543 Problem . . . . 543 Solution . . . . 544 Application. . 544 Impacts . . . . 546 Relationships. . . . 546 Case Study Example. . 548 Intermediate Routing 549 Problem . . . . 549 Solution . . . . 551 Application. . 552 Impacts . . . . 553 Relationships. . . . 553 Case Study Example. . 556 State Messaging . . 557 Problem . . . . 557 Solution . . . . 558 Application. . 560 Impacts . . . . 561 Relationships. . . . 561 Case Study Example. . 562 Service Callback . . 566 Problem . . . . 566 Solution . . . . 568 Application. . 568 Impacts . . . . 570 Relationships. . . . 570 Case Study Example. . 571 Service Instance Routing . . 574 Problem . . . . 574 Solution . . . . 576 Application. . 576 Impacts . . . . 578 Relationships. . . . 578 Case Study Example. . 579 Asynchronous Queuing . . . 582 Problem . . . . 582 Solution . . . . 584 Application. . 584 Impacts . . . . 587 Relationships. . . . 588 Case Study Example. . 589 Reliable Messaging 592 Problem . . . . 592 Solution . . . . 593 Application. . 593 Impacts . . . . 594 Relationships. . . . 595 Case Study Example. . 596 Event-Driven Messaging 599 Problem . . . . 599 Solution . . . . 600 Application. . 602 Impacts . . . . 602 Relationships. . . . 602 Case Study Example. . 604 CHAPTER 19: Composition Implementation Patterns . . 605 Agnostic Sub-Controller 607 Problem . . . . 607 Solution . . . . 608 Application. . 610 Impacts . . . . 610 Relationships. . . . 610 Case Study Example. . 612 Composition Autonomy . . . 616 Problem . . . . 616 Solution . . . . 618 Application. . 619 Impacts . . . . 619 Relationships. . . . 620 Case Study Example. . 620 Atomic Service Transaction 623 Problem . . . . 623 Solution . . . . 624 Application. . 626 Impacts . . . . 626 Relationships. . . . 628 Case Study Example. . 629 Compensating Service Transaction . . 631 Problem . . . . 631 Solution . . . . 633 Application. . 633 Impacts . . . . 635 Relationships. . . . 635 Case Study Example. . 636 CHAPTER 20: Service Interaction Security Patterns . . 639 Data Confidentiality641 Problem . . . . 641 Solution . . . . 643 Application. . 643 Impacts . . . . 644 Relationships. . . . 645 Case Study Example. . 646 Data Origin Authentication. 649 Problem . . . . 649 Solution . . . . 650 Application. . 651 Impacts . . . . 652 Relationships. . . . 653 Case Study Example. . 653 Direct Authentication 656 Problem . . . . 656 Solution . . . . 657 Application. . 657 Impacts . . . . 658 Relationships. . . . 659 Case Study Example. . 660 Brokered Authentication 661 Problem . . . . 661 Solution . . . . 662 Application. . 663 Impacts . . . . 665 Relationships. . . . 665 Case Study Example. . 666 CHAPTER 21: Transformation Patterns . . . . 669 Data Model Transformation 671 Problem . . . . 671 Solution . . . . 672 Application. . 673 Impacts . . . . 674 Relationships. . . . 674 Case Study Example. . 677 Data Format Transformation . . . 681 Problem . . . . 681 Solution . . . . 681 Application. . 683 Impacts . . . . 683 Relationships. . . . 683 Case Study Example. . 685 Protocol Bridging . 687 Problem . . . . 687 Solution . . . . 688 Application. . 688 Impacts . . . . 690 Relationships. . . . 690 Case Study Example. . 692 PART V: SUPPLEMENTAL CHAPTER 22: Common Compound Design Patterns . . . 697 "Compound" vs. "Composite" . . . 698 Compound Patterns and Pattern Relationships . . . 698 Joint Application vs. Coexistent Application. . . . . . 699 Compound Patterns and Pattern Granularity . . . . . 700 Orchestration. 701 Enterprise Service Bus . 704 Service Broker 707 Canonical Schema Bus . 709 Official Endpoint . . 711 Federated Endpoint Layer . 713 Three-Layer Inventory. 715 CHAPTER 23: Strategic Architecture Considerations. . 717 Increased Federation . 718 Increased Intrinsic Interoperability . . 721 Increased Vendor Diversification Options. . 723 Increased Business and Technology Alignment. . . 725 Increased ROI . 727 Increased Organizational Agility 728 Reduced IT Burden. 729 CHAPTER 24: Principles and Patterns at the U.S. Department of Defense . 731 The Business Operating Environment (BOE) . . . . . 733 Principles, Patterns, and the BOE . . 734 Incorporation of Information Assurance (IA) . . 736 Adherence to Standards . 736 Data Visibility, Accessibility, and Understandability to Support Decision Makers 736 Loosely Coupled Services 736 Authoritative Sources of Trusted Data 737 Metadata-Driven Framework for Separation from Technical Details . 737 Support Use of Open Source Software . . . 738 Emphasize Use of Service-Enabled Commercial Off-the-Shelf (COTS) Software . 738 Participation in the DoD Enterprise 738 Support Mobility Users & Devices . . 738 The Future of SOA and the DoD 739 SOADoD.org . . 739 PART VI: APPENDICES APPENDIX A: Case Study Conclusion 743 Cutit Saws Ltd. 744 Alleywood Lumber Company 744 Forestry Regulatory Commission (FRC) . . . 745 APPENDIX B: Candidate Patterns . . 747 APPENDIX C: Principles of Service-Orientation . . 749 Standardized Service Contract . 751 Service Loose Coupling 753 Service Abstraction . 755 Service Reusability . 756 Service Autonomy . . 758 Service Statelessness . 760 Service Discoverability 762 Service Composability 764 APPENDIX D: Patterns and Principles Cross-Reference . . . 767 APPENDIX E: Patterns and Architecture Types Cross-Reference . . . 775 About the Author . . . 783 About the Contributors . 784 Index of Patterns . . . 791 Index . 795 Forewords & Introductions