Discovering unknown with EventStorming ConFoo

Transcript

1. Mariusz Gil DISCOVERING UNKNOWN WITH @mariuszgil
3. https://www.tripled.io/img/DDD-books.jpg
4. CAPTURE The knowledge @mariuszgil
5. Embed Into code @mariuszgil
6. Protect From the world @mariuszgil
7. The critical complexity of most software projects is in understanding the domain itself Eric Evans @mariuszgil
8. Given… when… then… @mariuszgil
9. Initial idea
10. Reality
13. Meet& tELL your STORY @mariuszgil
16. @mariuszgil
17. @mariuszgil
18. Reservation requested @mariuszgil
19. Reservation requested Reservation accepted @mariuszgil
20. Reservation requested Reservation accepted Availability and Limits checked @mariuszgil
21. Reservation requested Reservation accepted Availability and Limits checked @mariuszgil
22. Reservation requested Reservation accepted Availability and Limits checked @mariuszgil
23. Reservation requested Reservation accepted Availability and Limits checked customer @mariuszgil
24. Reservation requested Reservation accepted Availability and Limits checked customer Reservation rejected How to handle rejections? @mariuszgil
25. Reservation requested Reservation accepted Availability and Limits checked customer Reservation rejected How to handle rejections? Similar offer Proposed @mariuszgil
26. Reservation requested Reservation accepted Availability and Limits checked customer Reservation rejected How to handle rejections? Similar offer Proposed agent @mariuszgil
27. Airline ticket Api gateway Reservation requested Reservation accepted Availability and Limits checked customer Reservation rejected How to handle rejections? Similar offer Proposed agent @mariuszgil
28. Airline ticket Api gateway Reservation requested Availability and Limits checked customer Reservation rejected How to handle rejections? Similar offer Proposed agent Email gateway Reservation accepted @mariuszgil
29. Airline ticket Api gateway Reservation requested Availability and Limits checked customer Reservation rejected How to handle rejections? Similar offer Proposed agent Email gateway Confirmation Delivered Reservation accepted @mariuszgil
30. Airline ticket Api gateway Reservation requested Availability and Limits checked customer Reservation rejected How to handle rejections? Similar offer Proposed agent Email gateway Confirmation Delivered Reservation accepted $ $ @mariuszgil
31. Airline ticket Api gateway Reservation requested Availability and Limits checked customer Reservation rejected How to handle rejections? Similar offer Proposed agent Email gateway Confirmation Delivered Reservation accepted $ $ How to handle service Downtimes? @mariuszgil
32. Airline ticket Api gateway Reservation requested Availability and Limits checked customer Reservation rejected How to handle rejections? Similar offer Proposed agent Email gateway Confirmation Delivered Reservation accepted $ $ How to handle service Downtimes? Some customers Have phones Only! @mariuszgil
41. Bad decisions Cost a lot… @mariuszgil
48. It’s DEVELoper (mis)understanding Not expert knowledge That get’s released in production Alberto Brandolini @mariuszgil
49. Big picture Event storming @mariuszgil
50. Design level Event storming @mariuszgil
51. Aggregate Event Actor Command / Decision Read model External System Policy @mariuszgil Command Query
52. @mariuszgil https://docs.axoniq.io/reference-guide/v/3.3/part-i-getting-started/architecture-overview
53. Payment Registered Loyalty points registered Loyalty points calculated Upgrade limits reached Account upgraded to higher status @mariuszgil
54. Payment Registered Loyalty points registered Loyalty points calculated Upgrade limits reached Account upgraded to higher status Register loyalty points @mariuszgil
55. Payment Registered Loyalty points registered Loyalty points calculated Upgrade limits reached Account Status upgraded Register loyalty points Upgrade account status @mariuszgil
56. Payment Registered Loyalty points registered Loyalty points calculated Upgrade limits reached Account Status upgraded Register loyalty points Upgrade account status required points Levels Account upgrading policy @mariuszgil
57. Payment Registered Loyalty points registered Loyalty points calculated Upgrade limits reached Account Status upgraded Register loyalty points Upgrade account status required points Levels Account upgrading policy Reservations and payments history c.service @mariuszgil
58. Payment Registered Loyalty points calculated Upgrade limits reached Account Status upgraded Upgrade account status required points Levels Account upgrading policy Loyalty account Loyalty points registered Register loyalty points Reservations and payments history c.service @mariuszgil
59. Payment Registered Loyalty points calculated Upgrade limits reached Account Status upgraded Upgrade account status required points Levels Account upgrading policy Loyalty account Loyalty points registered Register loyalty points Reservations and payments history c.service @mariuszgil
60. Outcomes @mariuszgil
61. Possible implementation Solution @mariuszgil There are many of them!!!!!!
62. business domain logic application logic infrastructure
63. business logic application logic infrastructure
64. business logic application logic infrastructure aggregate Event publishing command domain event
65. @Entity // Mark this aggregate as a JPA Entity public class MyAggregate { @Id private String id; // fields containing state... @CommandHandler public MyAggregate(CreateMyAggregateCommand command) { // ... update state apply(new MyAggregateCreatedEvent(...)); } // constructor needed by JPA protected MyAggregate() { } } Event Command / Decision
66. domain event domain event business logic application logic infrastructure domain event aggregate domain event event sourcing
67. public class MyAggregateRoot { @AggregateIdentifier private String aggregateIdentifier; // fields containing state... @CommandHandler public MyAggregateRoot(CreateMyAggregate cmd) { apply(new MyAggregateCreatedEvent(cmd.getId())); } // constructor needed for reconstruction protected MyAggregateRoot() { } @EventSourcingHandler private void handleMyAggregateCreatedEvent(MyAggregateCreatedEvent event) { // make sure identifier is always initialized properly this.aggregateIdentifier = event.getMyAggregateIdentifier(); // ... update state } } Aggregate
68. domain event domain event domain event domain event business logic application logic infrastructure domain event domain event command domain event policy process managers
69. business logic application logic infrastructure domain event command saga domain event command domain event Compensate command policy policy
70. public class OrderManagementSaga { private boolean paid = false; private boolean delivered = false; @Inject private transient CommandGateway commandGateway; @StartSaga @SagaEventHandler(associationProperty = "orderId") public void handle(OrderCreatedEvent event) { // client generated identifiers ShippingId shipmentId = createShipmentId(); InvoiceId invoiceId = createInvoiceId(); // associate the Saga with these values, before sending the commands SagaLifecycle.associateWith("shipmentId", shipmentId); SagaLifecycle.associateWith("invoiceId", invoiceId); // send the commands commandGateway.send(new PrepareShippingCommand(...)); commandGateway.send(new CreateInvoiceCommand(...)); } @SagaEventHandler(associationProperty = "shipmentId") public void handle(ShippingArrivedEvent event) { delivered = true; if (paid) { SagaLifecycle.end(); } } @SagaEventHandler(associationProperty = "invoiceId") public void handle(InvoicePaidEvent event) { paid = true; if (delivered) { SagaLifecycle.end(); } } // ... } Reactive Policy
71. read model business logic application logic infrastructure read models domain event domain event domain event domain event read model read model read model
72. business logic application logic infrastructure
73. business logic application logic infrastructure
74. business logic application logic infrastructure BUS Event
75. Event Command / Decision Event Event Aggregate
76. public class MyCommandComponentTest { private FixtureConfiguration<MyAggregate> fixture; @Before public void setUp() { fixture = new AggregateTestFixture<>(MyAggregate.class); } @Test public void testFirstFixture() { fixture.given(new MyEvent(1)) .when(new TestCommand()) .expectSuccessfulHandlerExecution() .expectEvents(new MyEvent(2)); /* } } Event Command / Decision Event Event Aggregate Given When Then
77. Command / Decision Read model Event Event Given When Then
78. Event Command / Decision Aggregate Read model Given When Then Event
79. DDD is not for you? @mariuszgil
80. Event Command / Decision Aggregate Read model Reactive Policy
81. Event Command / Decision Aggregate Read model Reactive Policy Record Inserted / Changed / Deleted Insert / Update / Delete / Truncate / … Record / Table Select / View Trigger / Procedure
82. Takeaways @mariuszgil
83. Big Picture Events Processes & Flows Hot Spots Systems Boundaries People @mariuszgil
84. Process Modeling Commands Policies Read Models Value Propositions Personas Metrics & Alerts @mariuszgil
85. Software Design Aggregates Policies Reactive Logic Read Models @mariuszgil
86. Communication! @mariuszgil
87. Building common understanding @mariuszgil
88. From production session
89. From production session
90. From alberto bandolino workshop
91. From production session
92. Software development is learning process Working code is a side effect Alberto Brandolini @mariuszgil
94. What’s next? @mariuszgil
98. THANK YOU! @mariuszgil