Building Microservices: Designing Fine-Grained Systems

Table of Contents......Page 5
Why I Wrote This Book......Page 15
Navigating This Book......Page 16
Safari® Books Online......Page 18
Acknowledgments......Page 19
Chapter 1. Microservices......Page 21
Small, and Focused on Doing One Thing Well......Page 22
Autonomous......Page 23
Technology Heterogeneity......Page 24
Scaling......Page 25
Ease of Deployment......Page 26
Optimizing for Replaceability......Page 27
What About Service-Oriented Architecture?......Page 28
Shared Libraries......Page 29
Modules......Page 30
Summary......Page 31
Inaccurate Comparisons......Page 33
An Evolutionary Vision for the Architect......Page 35
Zoning......Page 36
A Principled Approach......Page 37
Principles......Page 38
A Real-World Example......Page 39
The Required Standard......Page 40
Architectural Safety......Page 41
Tailored Service Template......Page 42
Exception Handling......Page 44
Governance and Leading from the Center......Page 45
Building a Team......Page 46
Summary......Page 47
Introducing MusicCorp......Page 49
High Cohesion......Page 50
Shared and Hidden Models......Page 51
Premature Decomposition......Page 53
Turtles All the Way Down......Page 54
The Technical Boundary......Page 56
Summary......Page 57
Keep Your APIs Technology-Agnostic......Page 59
Interfacing with Customers......Page 60
The Shared Database......Page 61
Synchronous Versus Asynchronous......Page 62
Orchestration Versus Choreography......Page 63
Remote Procedure Calls......Page 66
Brittleness......Page 67
REST......Page 69
REST and HTTP......Page 70
Hypermedia As the Engine of Application State......Page 71
JSON, XML, or Something Else?......Page 73
Downsides to REST Over HTTP......Page 74
Technology Choices......Page 75
Complexities of Asynchronous Architectures......Page 77
Reactive Extensions......Page 78
Client Libraries......Page 79
Access by Reference......Page 80
Defer It for as Long as Possible......Page 82
Catch Breaking Changes Early......Page 83
Coexist Different Endpoints......Page 84
Use Multiple Concurrent Service Versions......Page 86
Toward Digital......Page 87
API Composition......Page 88
UI Fragment Composition......Page 89
Backends for Frontends......Page 91
Integrating with Third-Party Software......Page 93
Integration Spaghetti......Page 94
On Your Own Terms......Page 95
The Strangler Pattern......Page 97
Summary......Page 98
It’s All About Seams......Page 99
Breaking Apart MusicCorp......Page 100
Security......Page 101
Getting to Grips with the Problem......Page 102
Example: Breaking Foreign Key Relationships......Page 104
Example: Shared Static Data......Page 105
Example: Shared Data......Page 106
Example: Shared Tables......Page 107
Refactoring Databases......Page 108
Transactional Boundaries......Page 109
Abort the Entire Operation......Page 111
Distributed Transactions......Page 112
The Reporting Database......Page 113
Data Retrieval via Service Calls......Page 115
Data Pumps......Page 116
Event Data Pump......Page 118
Backup Data Pump......Page 119
Cost of Change......Page 120
Understanding Root Causes......Page 121
Summary......Page 122
A Brief Introduction to Continuous Integration......Page 123
Are You Really Doing It?......Page 124
Mapping Continuous Integration to Microservices......Page 125
Build Pipelines and Continuous Delivery......Page 127
And the Inevitable Exceptions......Page 128
Platform-Specific Artifacts......Page 129
Operating System Artifacts......Page 130
Custom Images......Page 131
Immutable Servers......Page 133
Environments......Page 134
Service Configuration......Page 135
Multiple Services Per Host......Page 136
Application Containers......Page 138
Single Service Per Host......Page 139
Platform as a Service......Page 140
Automation......Page 141
From Physical to Virtual......Page 142
Traditional Virtualization......Page 143
Linux Containers......Page 144
Docker......Page 146
A Deployment Interface......Page 147
Environment Definition......Page 148
Summary......Page 150
Types of Tests......Page 151
Test Scope......Page 152
Service Tests......Page 154
Trade-Offs......Page 155
Implementing Service Tests......Page 156
Mocking or Stubbing......Page 157
Those Tricky End-to-End Tests......Page 158
Flaky and Brittle Tests......Page 160
How Long?......Page 161
The Great Pile-up......Page 162
Test Journeys, Not Stories......Page 163
Consumer-Driven Tests to the Rescue......Page 164
Pact......Page 165
So Should You Use End-to-End Tests?......Page 167
Separating Deployment from Release......Page 168
Canary Releasing......Page 169
Mean Time to Repair Over Mean Time Between Failures?......Page 170
Cross-Functional Testing......Page 171
Performance Tests......Page 172
Summary......Page 173
Chapter 8. Monitoring......Page 175
Single Service, Multiple Servers......Page 176
Multiple Services, Multiple Servers......Page 177
Logs, Logs, and Yet More Logs…......Page 178
Metric Tracking Across Multiple Services......Page 179
Service Metrics......Page 180
Synthetic Monitoring......Page 181
Correlation IDs......Page 182
The Cascade......Page 184
Consider the Audience......Page 185
The Future......Page 186
Summary......Page 187
Authentication and Authorization......Page 189
Common Single Sign-On Implementations......Page 190
Single Sign-On Gateway......Page 191
Fine-Grained Authorization......Page 192
Allow Everything Inside the Perimeter......Page 193
Use SAML or OpenID Connect......Page 194
Client Certificates......Page 195
HMAC Over HTTP......Page 196
API Keys......Page 197
The Deputy Problem......Page 198
Go with the Well Known......Page 200
Encrypt Backups......Page 201
Intrusion Detection (and Prevention) System......Page 202
Operating System......Page 203
A Worked Example......Page 204
Be Frugal......Page 206
Baking Security In......Page 207
Summary......Page 208
Evidence......Page 211
Netflix and Amazon......Page 212
Adapting to Communication Pathways......Page 213
Service Ownership......Page 214
Feature Teams......Page 215
Internal Open Source......Page 216
Maturity......Page 217
The Orphaned Service?......Page 218
Case Study: RealEstate.com.au......Page 219
Conway’s Law in Reverse......Page 221
People......Page 222
Summary......Page 223
Failure Is Everywhere......Page 225
How Much Is Too Much?......Page 226
Degrading Functionality......Page 227
Architectural Safety Measures......Page 228
The Antifragile Organization......Page 230
Timeouts......Page 231
Circuit Breakers......Page 232
Bulkheads......Page 234
Idempotency......Page 235
Scaling......Page 236
Spreading Your Risk......Page 237
Load Balancing......Page 239
Worker-Based Systems......Page 240
Starting Again......Page 241
Scaling for Reads......Page 242
Scaling for Writes......Page 243
CQRS......Page 244
Caching......Page 245
Caching in HTTP......Page 246
Hiding the Origin......Page 248
Keep It Simple......Page 249
Autoscaling......Page 250
CAP Theorem......Page 252
Sacrificing Availability......Page 253
Sacrificing Partition Tolerance?......Page 254
It’s Not All or Nothing......Page 255
Service Discovery......Page 256
DNS......Page 257
Zookeeper......Page 258
Consul......Page 259
Eureka......Page 260
Documenting Services......Page 261
HAL and the HAL Browser......Page 262
Summary......Page 263
Principles of Microservices......Page 265
Adopt a Culture of Automation......Page 266
Decentralize All the Things......Page 267
Isolate Failure......Page 268
When Shouldn’t You Use Microservices?......Page 269
Parting Words......Page 270
Index......Page 271
About the Author......Page 280