Spring microservices in depth using domain driven design

PlГ¶d notes that this is also one the core ideas of microservices, they should be designed so that they can evolve. With an inflexible architecture or if a system becomes too complex it may be helpful to create a Large-scale structure across bounded contexts and letting this structure evolve towards a betterВ understanding of the high-level concepts. ItвЂ™s a group of domain objects handled together and with one entity the aggregate root through which all requests and responsible for the lifecycle of the aggregate. This is an interesting option especially when migrating to a microservices or a Self-Contained Systems (SCS) architecture since the ACL works as a protecting shield againstВ the outside.ДЄmong the internal building blocks PlГ¶d notes the special importance of the aggregate. Anticorruption layer ( ACL), where a client isolates its model from another model using a translation.Customer вЂ“ Supplier, with one context acting as a customer asking for features from another context, the supplier.PlГ¶d notes that this also increases the dependency. Shared kernel meaning two contexts or models share a subset of a domain including code.Patterns for common types of relationships between two contexts include:

It can also be a great starting point for future transformations. For organisations with an existing landscape wanting to move to microservices PlГ¶d believes that a context map may be especially useful. Using a customer as an example each bounded context has its own model and view of a customer and for PlГ¶d this is a major enabler for independent microservices.ДЄ context map shows all bounded contexts and their relation to each other and also describes the contract between them. A bounded context contains models describing the domain and is also a boundary for the meaning of these models. Distillation with ways to distil a core domain from an already grown system.ДЄny sophisticated business domain consists of one or more bounded contexts, each responsible for one part of the domain.Large-scale structures for creating a structure using evolving order and responsibility layers.Internal building blocks, using tactical patterns like entities, aggregates and repositories when designing the internals of a bounded context.Strategic design which is mainly about Bounded context, but Context map and other patterns are also important.PlГ¶d, Principal Consultant at innoQ, believes DDD can help in four major areas when building microservices: Correspondingly DDD is just not about entities, value objects and repositories, Michael PlГ¶d claimed in his presentation at the recent microXchg conference in Berlin showing how DDD can be used when creating microservices. Microservices and Domain-Driven Design (DDD) are not only about Bounded contexts, although a fundamental tool for defining granularity of microservices there are other important concepts as well.

Spring microservices in depth using domain driven design