Implementing SOA

Differentiation 153 Characterizing Processes 159 Patterns of Interaction 163 Interaction Patterns Characterize Participants 171 Requirements Reflect Design 172 Summary 175 Key Requirements Questions 177 Suggested Reading 178 Chapter 9: Business Process Architecture 179 Results 180 Participants and Their Roles 182 Activities and Scenarios 186 Modeling Scenarios 191 Modeling Interactions 198 How Much Detail Is Enough? 204 Guidelines for Using Activity Diagrams 206 Summary 207 Key Business Process Architecture Questions 208 Suggested Reading 209 Chapter 10: Milestones 211 Basic Process Milestones 211 Variations in Milestone Sequences 214 Grouped Milestones 215 Recognizing Milestones Requires Design 216 Using Milestones to Reduce Inter-Process Coupling 217 Summary 218 Key Milestone Questions 219 Chapter 11: Process Constraints 221 Business Process Constraints Drive System Constraints 222 Performance Constraints 224 High Availability and Fault Tolerance 231 Security 238 Reporting, Monitoring, and Management 240 Exception Handling 242 Test and Acceptance 243 Compliance Constraints 245 Summary 246 Key Process Constraint Questions 247 Suggested Reading 248 Chapter 12: Related Processes 249 Identifying Services 252 Triggering Events 258 Summary 264 Key Related Process Questions 265 Chapter 13: Modeling the Domain 267 UML Class Notation 269 ATM Example Domain Model 274 Reverse Engineering the Domain Model 276 Domain Modeling Summary 277 Key Domain Modeling Questions 279 Suggested Reading 279 Chapter 14: Enterprise Architecture: Process and Domain Modeling 281 Process and Domain Modeling Responsibilities 282 Establishing Standards and Best Practices 283 Managing Process and Domain Knowledge Transfer 285 Reviewing Project Models 286 Maintaining the Business Process and Domain Model Repository 287 Defining Business Process Patterns 288 Defining Common Data Model Representations 288 Summary 289 Key Enterprise Process and Domain Modeling Questions 290 Part III: The Systems Perspective 291 Chapter 15: Systems Architecture Overview 293 The Challenge of Architecting Distributed Systems 294 Learning from the CORBA Experience 294 Efficiently Exploring Architectures 300 Summary 303 Key Systems Architecture Overview Questions 304 Chapter 16: Top-Level Systems Architecture 305 First-Cut Structure 305 Initial Evaluation 307 Communications and Modularization 309 Service Identification and Performance 312 Modeling System Interactions 312 Modeling Deployment 318 Addressing Performance 322 Early Architecture Evaluation 325 Key Top-Level Systems Architecture Questions 327 Suggested Reading 328 Part IV: Communications 329 Chapter 17: Transport 331 Transport Technology 332 Selecting Transports 336 Messaging Server Topology 340 Capacity 345 Point-to-Point Interaction Patterns 347 Point-to-Point Intermediaries 348 Transport-Supplied Services 350 Summary 351 Key Transport Questions 351 Suggested Reading 352 Chapter 18: Adapters 353 API-Based Adapters 354 Database-Based Adapters 355 Combining API and Database Approaches 356 File-Based Adapters 357 Protocol-Based Adapters 357 Documenting Adapter Usage 358 Summary 359 Key Adapter Questions 360 Chapter 19: Enterprise Architecture: Communications 361 Defining a Communications Strategy 361 Interaction Standards 362 Standardizing Adapters 363 Summary 364 Key Enterprise Architecture Communications Questions 364 Part V: Data and Operations 367 Chapter 20: Data Challenges 369 Chapter 21: Messages and Operations 371 Message Semantics and Operation Names 371 Transport Destinations and Operation Bundling 374 Content Representation 377 Content Transformation 378 Reference Data in Content Transformation 380 Summary 381 Key Messages and Operations Questions 381 Chapter 22: Data Consistency: Maintaining One Version of the Truth 383 Approaches to Maintaining Data Consistency 384 Cached Data with a Single System of Record 385 Coordinated Updates via Distributed Transactions 390 Edit Anywhere, Reconcile Later 390 Dealing with Data Inconsistencies 391 Data Management Business Processes 393 Summary 394 Key Data Consistency Questions 394 Suggested Reading 395 Chapter 23: Common Data Models (CDM) 397 What Is a Common Data Model? 397 CDM Relationship to the Domain Model 402 The Need for Multiple CDM Representations 405 Planning for CDM Changes 407 When to Use Common Data Models 411 Summary 415 Key Common Data Model Questions 416 Chapter 24: Identifiers (Unique Names) 417 Identity (Unique Name) Authorities 418 Hierarchical Identifiers 419 Coping with Identity Errors 423 Mapping Identifiers 429 Summary 433 Key Identifier Questions 434 Chapter 25: Results Validation 435 Checking Enumerated Values 436 Where and When to Validate 437 Summary 438 Key Data Validation Questions 439 Chapter 26: Enterprise Architecture: Data 441 Naming Schemes 441 Architecting Content Transformation 443 Systems of Record 445 Common Data Models 446 Identifiers 447 Data Quality Management 448 Summary 449 Key Enterprise Architecture Data Questions 450 Part VI: Coordination 451 Chapter 27: Coordination and Breakdown Detection 453 Activity Execution Management Patterns (AEMPs) Involving Interactions 454 Coordination Pattern Styles 456 Fire-and-Forget Coordination Patterns 457 Request-Reply Patterns 460 Delegation 465 Delegation with Confirmation 467 Summary 468 Key Coordination Questions 469 Chapter 28: Transactions: Coordinating Two or More Activities 471 Two-Phase Commit Distributed Transactions 472 Limitations of Two-Phase Commit Protocols 475 Compensating Transactions 476 Working around the Limitations of Compensating Transactions 476 Summary 478 Key Transaction Questions 479 Suggested Reading 479 Chapter 29: Process Monitors and Managers 481 Process Monitoring 483 Minimizing the Impact of Monitoring Breakdowns 484 The Process Manager as a Monitor 485 Process Management Limitations 486 Summary 488 Key Process Monitoring and Management Questions 488 Chapter 30: Detecting and Responding to Breakdowns 489 Selecting Coordination Patterns to Improve Breakdown Detection 489 Responding to Breakdowns 493 Summary 504 Key Breakdown Detection and Recovery Questions 505 Chapter 31: Enterprise Architecture: Coordination 507 Preferred Coordination Patterns 507 Breakdown Recording 509 Breakdown Annunciation 510 Recovery Processes 511 Summary 511 Key Enterprise Coordination Questions 512 Part VII: High Availability, Fault Tolerance, and Load Distribution 513 Chapter 32: High Availability and Fault Tolerance Fundamentals 515 Fault Tolerance Strategies 516 Failure Detection Strategies 517 Failover Management 519 Redirecting Clients 520 Summary 522 Key High-Availability and Fault Tolerance Questions 523 Chapter 33: Stateless and Stateful Failover 525 Stateless and Stateful Components 525 Stateless Failover 525 Saving Work in Progress through Coordination 526 Stateful Failover 528 Storage Replication 530 Summary 540 Key Failover Questions 541 Suggested Reading 541 Chapter 34: Multiple Component Failover 543 Intra-Site versus Inter-Site Failover 543 Clustering: An Intra-Site Failover Technique 545 Coordinating Peer Application Failover with Asynchronous Replication 546 Making a Business Process Fault-Tolerant 548 Summary 550 Key Multi-Component Failover Questions 551 Chapter 35: Workload Distribution 553 Work Assignment Strategies 553 Distribution Management and Work Completion 554 The Sequencing Problem 556 Access to Shared Persistent State 557 Geographic Workload Distribution 558 Summary 558 Key Workload Distribution Questions 559 Chapter 36: Enterprise Architecture: Fault Tolerance, High Availability, and Load Distribution 561 Business Process Categorization 563 Information Storage 565 Individual Component and Service Failover Patterns 565 Composite Patterns for FT and HA Services 566 Composite Patterns for FT and HA Business Processes 568 Summary 568 Key Enterprise Fault Tolerance, High-Availability, and Load Distribution Questions 569 Suggested Reading 569 Part VIII: Completing the Architecture 571 Chapter 37: Process Security 573 Security Information Classification 574 Identity and Authentication 574 Authorization 576 Encryption 579 Digital Signatures 580 Other Security-Related Requirements 580 Reference Data Servers and Performance 581 Trust Zones 582 Channel Enforcement 583 Zone Enforcement and Policy Agents 585 Multi-Zone Security 586 Summary 587 Key Security Questions 588 Suggested Reading 589 Chapter 38: Process Monitoring 591 Performance Monitoring 592 Monitoring Process Status 594 Supervisory Processes 595 The Impact of Monitoring on Performance 596 Summary 596 Key Process Monitoring Questions 597 Chapter 39: Architecture Evaluation 599 Usability 600 Performance 600 Cost and Schedule Feasibility 612 Observability 613 Ability to Evolve 613 Ability to Handle Stress Situations 614 Summary 615 Key Architecture Evaluation Questions 616 Suggested Reading 617 Chapter 40: Testing 619 Unit Testing, Test Harnesses, and Regression Testing 620 Integration Testing and Order of Assembly 621 Environments for Functional and System Testing 622 Performance Testing 623 Failure Mode Testing 627 Summary 628 Key Testing Questions 628 Part IX: Advanced Topics 631 Chapter 41: Representing a Complex Process 633 Eliding Communications Detail 634 Eliding Participant Activity Details 634 Eliding Supporting Participants 636 Abstracting Subprocesses 638 Summary 639 Key Complex Process Representation Questions 639 Chapter 42: Process Management and Workflow 641 Process Management 642 Styles of Work Assignment 647 Initiating Workflow 649 Making the Management Process Fault Tolerant 649 Human Interfaces 656 Related Processes 660 Prioritized Work 663 Dynamic Work Assignments 665 Dynamic Result and Process Definitions 666 Summary 668 Key Process Management and Workflow Questions 669 Suggested Reading 670 Chapter 43: The Enterprise Architecture Group 671 Half a Group Is Better than None--But Not Good Enough 672 Best Practice Development 672 Knowledge Transfer 673 Governance 675 Designing with Evolving Requirements 675 Summary 681 Key Enterprise Architecture Group Questions 682 Afterword 683 Focus Your Work 683 Seek the Expertise of Others 684 Be Pragmatic, But Consider the Long View 685 Index 687