Here we will discuss Layered Architecture in software development in every dimension for new Developers. With a history of creating and implementing a lot of architectural patterns, I have come to the conclusion that Layered Architecture is a basic concept for a developer to grasp. This blog will cover all the aspects of Layered Architecture and we will also have a look upon other Architectures. Along with comparison, we will also discuss the most common Use cases to understand it better.
Introduction to Layered Architecture
Layered Architecture is a design pattern for software that employs components that execute different tasks only. For instance, a parser might be one layer, whereas a compiler would be another. Traditional design’s elements are involved from the top. Layered approach obeys nice style for the development of large devices. Absolutely, it is to split as many tasks as possible into a separate unit of work, easily obtained in languages like C#.
Historical Context
Layered Architecture concept history dates back to the early days of software engineering. At the time, the seventies and eighties were the most booming of them all because software systems were more complex. To better manage the newly formed complexities, the Layered Architecture became ever more popular till it was enveloped all over the place.
Core Principles of Layered Architecture
Layered Architecture is based on three simple direct rules:
- Separation of Concerns : This is a principle that suggests different aspects of the software system should be handled by separate modules or components. In the Layered architecture, they are organized into a maze only to do a certain task without any hassle of any other unit. This in turn, makes things easy in the development process since each layer is responsible for its tasks. There is a reduction of complexity in the code and this makes everything very clear.
- Abstraction : Abstraction helps us hide the definition of a layer but at the same time, it can pass the necessary functionality to other layers so that they can communicate with it. This principle allows a higher level of modularity in the system and is more about metamorphosing or changing individual layers of a composite of the units without affecting other layers. Consequently, in the abstract layer, a module may seem to hide a whole configuration and the related entities while many of these functions might allow humans to access the same information through an interface.
- Modularity : Modularity is the practice of breaking a system into small, more accessible parts of concern. Each layer is a module with an interface defined, making it easier to reuse the code and quick reading of the system.
Typical Layers in Layered Architecture
The Layered Architecture comprises of four principal layers:
- Presentation Layer : This is the user’s interaction top layer directly. Its function is to display the necessary information to the customer and acquire the necessary input. Such can be the case where a web application consists of user interface components such as HTML, CSS, and JavaScript this layer might be included.
- Business Logic Layer : On the Application Layer or Business Logic Layer, resides the crucial functionality of the application. The layer automates prepared algorithms, executes the computation, and takes effective authority over the data flows between the communication layer and the data retrieval system.
- Data Access Layer : This layer integrates with a database or in some other way, getting access to the data. The duties of the layer are querying the database, inserting or updating records, data translation between the business logic layer format and the database format.
- Database Layer : Though not part of the application code, it is often referred to as the non-application layer. In fact, it contains the actual database management system and stored data.
Benefits of Layered Architecture
Layered Architecture has numerous advantages, namely:
1. Maintainability
Separating concerns into their own layers reveals the readability, maintainability, and updating abilities of each part without changing the rest. Decoupling layers further, some parts of the app can be changed by different developers with minimal risk of parallel work getting hindered.
2. Scalability
The multi-tiered architecture of Layered Architecture allows increment in the size of individual levels more easily. For example, you can bring more users to the application by scaling the top layers without the need to scale the whole application.
3. Testability
The implementation of Separation of Concerns in Layered Architecture makes it easier to write unit tests for individual components. Each subproject can be tested on its own, and thus the tests will be more complete and reliable.
Challenges of Layered Architecture
Though Layered Architecture combines all the benefits, it is not free from other challenges as well. For example:
1. Performance Overhead
In Layered Architecture introducing layers can cause a performance overhead to surface because data must flow through all layers. Each layer introduces its own set of operations, which can slow down response times, especially when multiple layers handle a single request.
2. Complexity
Implementing Layered Architecture in small applications may, actually, introduce unnecessary complexities. The situation with your project should be considered first so that you come up with a suitable decision either for this type of development or not.
Implementing Layered Architecture in .NET
Lets put our heads into Layered Architecture in a .NET application. We have got a simple model of book management through which we will explain the principles.
Step 1: Set up the Project Structure
Initially, you are required to create separate projects that correspond to the layers of the system.
BookStore.Presentation
BookStore.BusinessLogic
BookStore.DataAccess
Step 2: Define the Data Access Layer
In the DataAccess project, create a Book entity and a repository interface:
public class Book
{
public int Id { get; set; }
public string Title { get; set; }
public string Author { get; set; }
}
public interface IBookRepository
{
List GetAllBooks();
Book GetBookById(int id);
void AddBook(Book book);
}
Step 3: Implement the Business Logic Layer
In the BusinessLogic project, create a service that uses the repository:
public class BookService
{
private readonly IBookRepository _bookRepository;
public BookService(IBookRepository bookRepository)
{
_bookRepository = bookRepository;
}
public List GetAllBooks()
{
return _bookRepository.GetAllBooks();
}
public Book GetBookById(int id)
{
return _bookRepository.GetBookById(id);
}
public void AddBook(Book book)
{
// Add validation logic here
_bookRepository.AddBook(book);
}
}
Step 4: Create the Presentation Layer
In the Presentation project, create a plain console application that uses the BookService:
class Program
{
static void Main(string[] args)
{
IBookRepository repository = new InMemoryBookRepository();
BookService bookService = new BookService(repository);
// Add a book
bookService.AddBook(new Book { Title = "1984", Author = "George Orwell" });
// Get all books
var books = bookService.GetAllBooks();
foreach (var book in books)
{
Console.WriteLine($"{book.Title} by {book.Author}");
}
}
}
Here, you will see how the layers interact with each other, but they are strictly divided into modules so that the presentation layer is not familiar with the data access aspect of the project.
Comparison with Other Architectural Patterns
Whereas Layered Architecture is the most common model, other architectural patterns are available too. Let us compare some of them:
Onion Architecture
Onion Architecture is similar to Layered Architecture but with a more prominent role assigned to the domain model. The purpose of the separation of domain logic from data access and presentation is to simplify testing and later reuse the same domain model.
Strengths:
High testability of components
Emphasis on the domain model
Weaknesses:
It may be difficult to implement at first
The set-up period may require longer
Clean Architecture
Clean Architecture is a variation of the Layered Architecture that was proposed by Robert C. Martin and attempts to lessen the dependence on frameworks, UIs, and databases in the systems.
Strengths:
Less dependence on external frameworks
Test easily
Weaknesses:
The possibility of causing more boilerplate code
Can be excessive for smaller projects
Hexagonal Architecture
Ports and Adapters, also known as Hexagonal Architecture, aims to disjoin the components of application, digital and analog with the environment, both using the concept of ports and adapters.
Strengths:
The high flexibility and adaptability
Isolated testing is a breeze
Weaknesses:
May become too hard to learn and implement
An increased number of classes and interfaces might be required
Best Practices for Implementing Layered Architecture
To bring out the potential of the Layered Architecture, consider the following best practices:
- Have well-defined borders of the layers
- Use dependency injection to manage dependencies between layers
- Create good such practice as handling exceptions that are appropriate at any level
- Define the contract between layers using the interface construct
- Keep the domain model free from infrastructure-related matters
- Be careful about the circular layer dependencies
Future Trends and Evolving Role of Layered Architecture
As we see software development changing, so does the role of Layered Architecture:
Microservices: Layered Architecture is now incorporated into single microservices
Cloud-native applications: The architecture is evolving with layers possibly becoming distributed services in a cloud environment.
Serverless architectures: Layers are reimagining in serverless contexts, hence, the traditional layers are taken out and replaced with functions.
Conclusion
Layered Architecture remains as the prime building types for the software developers, and it is a structured and straightforward way to develop complicated applications. The basic principles of Layered Architecture, separation of concerns, abstraction, and modularity applied in complex systems of former advancements and literature are the main far-reaching ideas that lead to the new edge theories around them. Although newer patterns have arisen, either they consist of or they are built around the mantle of Layered Architecture.
Professional software developers can confirm that Layered Architecture is the base having found that the Layered Architecture understanding is the solid bottom for other complicated, even abstract architectural patterns, besides. It is an approach that is versatile and adaptive enough to be scaled according to different project sizes and types. Nonetheless, it is very necessary to remember what the project needs and the characteristics of the team in the selection of an architectural pattern.
Whether the creation consists only of a single website or an extensive internal framework each could, in turn, benefit from the principles of Layered Architecture that can be anyway used to build a reliable, flexible, and scalable software. Though the software realm is continually changing, the main ideas of Layered Architecture are most likely to stay vital. Yet since the technology is evolving, the classic notions of Layered Architecture should try out new paradigms and equipment as well.
