From CRUD to messages: a true story
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The document discusses the challenges faced in a financial application with a large user base and extensive data handling, highlighting issues such as fragmented logic and a fragile model. It emphasizes the need for a well-defined domain model that separates reading and writing operations, along with the implementation of domain events for better consistency. Various code examples illustrate the architecture and interactions within the system, underscoring the complexity and the proposal of using microservices to manage it.
![public interface ICompanyDossierService
{
void CloseCompanyFile(Guid id);
void SetInCharge(Guid id);
void SetAnalysisInCharge(Guid id);
IEnumerable<CompanyDossier> Search(Int16[] statuses, ...);
Guid Save(Guid companyFileId, String description, ...);
void DeleteAttachment(Guid id);
AttachmentStream GetAttachmentStream(Guid id);
...
}](https://image.slidesharecdn.com/slides-150509134322-lva1-app6891/85/From-CRUD-to-messages-a-true-story-6-320.jpg)
![An object model of the domain that
incorporates both behavior and data
[Martin Fowler - http://martinfowler.com/eaaCatalog/domainModel.html]](https://image.slidesharecdn.com/slides-150509134322-lva1-app6891/85/From-CRUD-to-messages-a-true-story-12-320.jpg)
![{
"_id" : {
"BucketId" : "Documents/Type",
"StreamId" : "1",
"CommitSequence" : 1
}
"CheckpointNumber" : NumberLong(9460),
"CommitId" : LUUID("5aeae871-8a94-294a-88b1-b2487e5d88d6"),
"CommitStamp" : ISODate("2013-11-21T14:58:08.500Z"),
"Dispatched" : true,
"Events" : [ {
"StreamRevision" : 1,
"Payload" : {
”Code" : ”SITBNC",
”Name" : "Situazione bancaria”,
“Enabled” : true,
“Metadata” : []
}
}],
"Headers" : {
"who" : "guest",
"when" : "2013112115580858",
"when/ticks" : NumberLong(635206462884868984),
"correlation" : "230b5b33-a2ce-4f7e-aa4e-a885c3f05274”
}
}](https://image.slidesharecdn.com/slides-150509134322-lva1-app6891/85/From-CRUD-to-messages-a-true-story-20-320.jpg)
From CRUD to messages: a true story
- 1. From CRUD to messages …a true story…
- 3. …il contesto… • Applicazione “finanziaria” • Circa 70 (230) utenti • 137.000+ (1.000.000+) aziende • 420.000+ (4.500.000+) bilanci • 38.000.000+ (650.000.000+) voci di bilancio • 16.000+ (85.000+) call/mese • “Pluggato” a servizi di terze parti • Picchi di lavoro “temporali”
- 6. public interface ICompanyDossierService { void CloseCompanyFile(Guid id); void SetInCharge(Guid id); void SetAnalysisInCharge(Guid id); IEnumerable<CompanyDossier> Search(Int16[] statuses, ...); Guid Save(Guid companyFileId, String description, ...); void DeleteAttachment(Guid id); AttachmentStream GetAttachmentStream(Guid id); ... }
- 9. ANY PROBLEM?
- 10. • Logica (mal) sparpagliata • Contesti non definiti • Modello “fragile” e poco propenso alle evoluzioni • Un unico modello per la lettura e per la scrittura • Prestazioni • UI “generazionalista”
- 12. An object model of the domain that incorporates both behavior and data [Martin Fowler - http://martinfowler.com/eaaCatalog/domainModel.html]
- 13. Use aggregates as unit of consistency across your domain model Protect your model with clearly defined bounded context Eric Evans
- 14. Use aggregates as unit of consistency across your domain model Protect your model with clearly defined bounded context Eric Evans
- 15. Use aggregates as unit of consistency across your domain model Protect your model with clearly defined bounded context Eric Evans
- 16. A single model cannot be appropriate for reporting, searching and transactional behavior Greg Young
- 18. State transition are an important part of our problem space and should be modeled within our domain Greg Young, 2008
- 20. { "_id" : { "BucketId" : "Documents/Type", "StreamId" : "1", "CommitSequence" : 1 } "CheckpointNumber" : NumberLong(9460), "CommitId" : LUUID("5aeae871-8a94-294a-88b1-b2487e5d88d6"), "CommitStamp" : ISODate("2013-11-21T14:58:08.500Z"), "Dispatched" : true, "Events" : [ { "StreamRevision" : 1, "Payload" : { ”Code" : ”SITBNC", ”Name" : "Situazione bancaria”, “Enabled” : true, “Metadata” : [] } }], "Headers" : { "who" : "guest", "when" : "2013112115580858", "when/ticks" : NumberLong(635206462884868984), "correlation" : "230b5b33-a2ce-4f7e-aa4e-a885c3f05274” } }
- 21. It’s really become clear to me in the last couple of years that we need a new building block and that is the domain events Eric Evans
- 22. It’s really become clear to me in the last couple of years that we need a new building block and that is the domain events Eric Evans
- 24. CONTACT CENTER FINANCE Compute Ratings Command Appointment Reserved
- 25. class ComputeRatingsCommandActivator : IConsumer<AppointmentReserved> { public async Task Consume( ConsumeContext<AppointmentReserved> context) { // COLLECT INFOS AND INITIALIZE THE COMMAND var endpoint = await context.GetSendEndpoint(“MyCommandEndpoint”); endpoint.Send(command); } }
- 26. CONTACT CENTER FINANCE Compute Ratings Command Appointment Reserved CONSULTANT Reserve Slot Command Appointment Reserved Appointment Reserved
- 27. class MachineInstance : SagaStateMachineInstance { public Guid CorrelationId { get; private set; } public State CurrentState { get; private set; } public Boolean ConsultantCommandResponse { get; set; } public Boolean FinanceCommandResponse { get; set; } } class StateMachine : MassTransitStateMachine<MachineInstance> { public StateMachine() { // MASSTRANSIT’S DSL TO DEFINE SAGA } public State Running { get; set; } public Event<AppointmentActivated> AppointmentActivated { get; private set; } public Event<ConsultantCommandExecuted> ConsultantCommandExecuted { get; private set; } public Event<FinanceCommandExecuted> FinanceCommandExecuted { get; private set; } }
- 28. GOOD / BAD
- 29. CONTACT CENTER FINANCE Compute Ratings Command State Transition Happened CONSULTANT Reserve Slot Command Resource Changed Resource Changed Resource Changed
- 31. class ComputeRatingsCommandActivator : IConsumer<AppointmentReserved> { public async Task Consume( ConsumeContext<AppointmentReserved> context) { // COLLECT INFOS AND INITIALIZE THE COMMAND var endpoint = await context.GetSendEndpoint(“MyCommandEndpoint”); endpoint.Send(command); } }
- 32. REST (HTTP) TO THE RESCUE
- 33. class ComputeRatingsCommandActivator : IConsumer<AppointmentReserved> { public async Task Consume( ConsumeContext<AppointmentReserved> context) { // USE API (MICROSERVICE?) TO COLLECT INFOS // AND INITIALIZE THE COMMAND var endpoint = await context.GetSendEndpoint(“MyCommandEndpoint”); endpoint.Send(command); } }
- 34. > GET /api/appointments/13 < 200 Ok < ETag: 686897696a7c876b7e < Last-Modified: Thu, 05 Jul 2012 15:31:30 GMT
- 35. > GET /api/appointments/13 < 301 Moved permanently < Location: http://...
- 36. DEPLOY?
- 37. SONO UNA CAGATA PAZZESCA!!! I MICROSERVICES…
- 39. WHEN? Tackling complexity in the heart of software
- 40. WHEN? Tackling complexity in the heart of software