My parents recently purchased an above-ground pool ahead of the summer season. The pool itself was in perfect condition, however the instructions for assembly were not included. Fortunately, these can easily be obtained online, allowing for easy access and printing of the instructions.
To my surprise, my father had managed to assemble the pool with little to no technical knowledge, apart from a few spare parts he had set aside. The instructions did not include replacements for any components and the pool was in a precarious state.
Many people tend to take a less considered approach, making changes as they become aware of further requirements. However, when it comes to computer programming, a well-defined application architecture is essential in the current business climate. Without it, delays caused by an inflexible architecture can have serious consequences.
A Comprehensive Guide to Application Architecture
The application architecture of a system is a fundamental concept. It outlines the software programmes that are required and how these interact to meet the business or user requirements. It is an important component as it provides the structure for the system and its software components. As such, the application architecture is essential in ensuring the success of the system.
It can be seen as a blueprint. For straightforward tasks, such as repairing a crack in a wall, one would not necessarily require a comprehensive plan of their home. However, if one is looking to construct a home, that is a different matter entirely. In the case of a pre-built home, the blueprint can act as a reference if renovations are to be carried out in the future.
Application architectures provide us with a valuable insight into how our system functions, allowing us to predict the implications of any changes we make. Having a well-documented architecture is essential for successful implementation, whether that be to update a section of our system or to expand its capabilities.
It is possible to make improvements to a system without a full understanding of its underlying architecture; however, this is not advisable. Software architects often refer to programs that have been built without due care and attention as having a “spaghetti architecture“, which is characterised by a complex network of connections between different parts of the application.
Then why is spaghetti architecture so problematic? So, to recap:
Poor service abstraction:
It is important to consider the consequences of having major services spread across multiple platforms. This can not only be difficult to manage, but also makes it hard to modify the code.Snowball effects:
When components are not isolated from each other, making changes to a part of the system could cause a domino effect, leading to the collapse of the entire program.Inflexible legacy systems:
The more complex the architecture, the more challenging it is to make changes. This can discourage updates, resulting in the proliferation of outdated components.
The Application Architecture Layers: What Do They Do?
The structure of the programme can be conceptualised in terms of levels, which is a widely accepted approach when creating AA charts. Ultimately, the most common architecture layers are:
- Layer of Presentation
- Data service layer
- Layer of business logic
- Information Layer
Regardless of the model chosen, a user interface, data delivery system, central processing unit for computations, and data storage are all crucial components. There are models with varying numbers of layers, but all will require these components.
Layer of Presentation
When an application receives user input, processes it, makes requests to data services, displays results and manages all other forms of user-application interaction, it is said to be operating at the “user interface” layer. In the context of online applications, this is the frontend, which makes use of technologies such as JavaScript, HTML and CSS to construct the visible part of the website.
Discrete-Event Simulation Using a Data-Service
This layer serves as a vital connection between the display layer and the business logic layer. It acts as an integral part of the security measures, providing a barrier between the user’s input and the core of the programme, ensuring the safety of both the developer and the users.
A Layer of Business Logic
This layer acts as the central nervous system of the system, exchanging and processing data, encoding user inputs and preparing data for transmission to the display layer. For example, in a dynamic website, this layer of code is responsible for deciding what data should be presented to the user. The system obtains the data from its repository, processes it as required and then sends it to the user’s screen.
Layer of Access to Informational Data
Here is where information is kept, often using a SQL or NoSQL database. This is the layer at which information is accessed and sent.
Are There Distinct Categories of Application Architectures?
It is not feasible to provide an exhaustive overview of all architectures in a single essay; however, we can focus on the most widely read ones.
Architectural Monoliths
The 3-tier architecture is a common name for this type of application. Despite the fact that it is considered outdated by modern standards, it is still used, especially in the case of legacy systems. This architecture is composed of a single, unified element that is managed by a single team. As the size of the program increases, it becomes increasingly difficult to handle due to the intricate web of commands it contains.
Architectural Model for Microservices
Applications in this architectural approach are structured as a set of related services. Each component does not need to use the same technology or even be written in the same language, and can be tested separately from the others. Each service supports a distinct essential business process, and can be implemented independently.
System Design without Relying on Servers for Events
This architectural model is based on a chain of independent systems, which are activated in response to events. Rather than relying on servers, this approach utilises services that are continuously monitoring for triggers, resulting in a lightweight and rapid design that is both easy to scale and cost-effective.
Construction in the Cloud
Compared to both microservice and event-driven architectures, cloud-optimised architectures offer the added advantage of scalability and hybrid capabilities. For example, they can automatically scale to meet demand and incorporate services from multiple cloud providers.
Never Say Never…
If you already have an application but it does not have a solid framework, it is not too late to make a diagram based on the existing application. It is often overlooked that taking the time to do this can prevent the project from becoming a convoluted mess of code. Therefore, it is important to not procrastinate and take the time to ensure a well-structured, organised approach.
