The Different Software Architectural Patterns You Should Know About

Before the construction of any building starts, there’s an architecture in place, which we call the blueprint. Based on this architecture or blueprint, the associated team proceeds with the construction work. In other words, construction isn’t possible without having the proper architecture of the building. The same goes for software systems or applications. You need to have a software architecture before you begin the development work.

There are plenty of software architectural patterns, and each provides unique solutions for different types of apps. But before we discuss the different software architectural patterns, let’s understand what an architectural pattern is.

What is Software Architectural Pattern?

Just like the blueprint of a building, software architecture is the blueprint of the software to be developed. It involves the overall structure of the software, the design and collection of components, and the interaction between the components.

With a defined architectural pattern, the software development team is able to build a product that the client or customer desires.

There are plenty of methods to organize the components in software architecture. The predefined organization of components in software architectures is what we call software architectural patterns. In other words, an architectural pattern allows you to define the structural schema for all types of software systems. Each pattern has a different style of organizing components but tends to solve a specific problem in software architectures.

Different Software Architectural Patterns

Let’s discuss the different types of software architectural patterns that have helped organizations scale up their business. Choose one that provides you with the desired functionality and quality attributes.

1. Layered Pattern

This architectural pattern is the most popular among developers. It is used to structure programs that encompass several groups of subtasks, each of which is at a distinct abstraction level and is represented by a layer in the software. Each layer provides services to the next higher layer in a unidirectional pattern.

The layers that are commonly found are the Presentation layer (also known as the UI layer), Application layer (also referred to as the Service layer), Business logic layer (also called as domain layer), and Data access layer (or persistence layer). 

Each of these layers has its own role in the application and is connected to the roles of other layers. For example, a Presentation layer would handle the entire UI and browser communication logic while certain business requests would be executed by the business logic layer.

Also, as we said, these layers communicate in a unidirectional pattern. For instance, when any input is initiated, the presentation layer interacts with the application layer, which further calls the business layer, and the message is finally sent to the data access layer that accesses the database.

The layered pattern architecture is generally used for desktop or eCommerce web applications.

2. Client-Server Pattern

The client-server architecture pattern comprises two key components- the ‘client’, which can also be called a service requester, and the ‘server’ or service provider. The two may be located within the same system but often interact with each other over a network on separate hardware.

The client component initiates interactions and requests services from the server. The server then provides the client with relevant services. The communication happens through the ports of both components. The client component has ports that describe the required services, while the server has ports that describe the services they provide.

Both components in a client-server architectural pattern are linked through request/reply connectors.

3. Event-driven Architecture Pattern

An event-driven architecture pattern is one of the highly performant architecture patterns, that has an agile approach where services or software operations are triggered by events. To understand what an event is, it is the generated reaction because of the state change when a user takes action in the software application developed using the EDA approach.

This architecture pattern consists of decoupled, single-purpose event processing components but are non-synchronous when it comes to receiving and processing events. Moreover, it is made up of two topologies. The first one is the Mediator which is used when a number of steps are needed to be orchestrated within an event bus through a central mediator, while the other one is the Broker which is used to chain events together without having to use a central mediator.

EDA pattern is ideal for building eCommerce websites or websites with JavaScript.

4. Microservices Pattern

The concept of the Microservices pattern is built around the collection of small programs (or microservices) that are coupled to form the actual application. These services tend to work interdependently. Although each microservice can be developed and deployed separately, its functionality is entwined with other microservices.

The separate deployment of units is a key feature in the microservices architecture pattern. This generates a streamlined delivery pipeline that enables easy deployment of microservices and improves application scalability.

Speaking of how it is actually used, small programs are developed for each service of an application independently, rather than building a bigger application. These small programs are then combined together to form a full-fledged application. So, the challenge of adding new features and modifying existing microservices without affecting other microservices is no longer there when using the microservices pattern to build the application.

The largest streaming platform in the world, Netflix is built using the Microservices architecture.

5. Model-View-Controller Pattern

The model-view-controller or MVC pattern divides an application into three segments: Model, View, and Controller.

The model is the central component of the system which contains the core functionality and data of the application. It controls the data and the logic of the application, however, it doesn’t involve the logic that explains how the data is presented to the user.

The view displays the information or the application data to the user and interacts with them. It can access data in the model but can neither understand the data nor how it can be manipulated.

The controller acts as a mediator between the model and the view, and handles the input from the user. It receives the external inputs from the view (user) and creates appropriate outputs.

The model, view, and container interact via some form of information, such as an event or a callback.

Programming languages like Python, Swift, Java, JavaScript make use of the MVC architecture. Web application frameworks like Django and Ruby on Rails are also based on the MVC architecture pattern.

6. Master-slave Architecture Pattern

The Master-slave pattern is made up of two components- master and slaves, and is useful when clients make multiple same requests. It functions with the master database launching multiple slave components to process those requests quickly. The master component distributes the tasks among identical slave components. Once the latter finishes its task, the distributed tasks are compiled by the master and a final result is computed from the results returned by the slaves.

What makes this architecture one of a kind is that each slave processes the requests simultaneously, thereby providing the results at the same time. This also means that the slave operations would not be considered complete until every slave has returned the result to the master.

Master-slave architecture pattern is well-suited for applications that can be divided into smaller segments for executing similar requests.

Final Word

You would find several other patterns apart from these software architectural patterns, such as pipe filter pattern, event-bus pattern, blackboard pattern, peer-to-peer pattern, broker pattern, interpreter pattern, space-based pattern, and controller-responder pattern. Each pattern is useful in different aspects of software development, however, the concept revolves around a common theme- defining the basic characteristics of the application, enhancing the product functionality, and enhancing efficiency and productivity of the app-building process.

Make sure to pick the suitable software architectural pattern as choosing the wrong one can delay the project and even result in software failure.