12 Software Architecture Styles Software Engineers Should Know
A brief introduction to Microservice, SOA, Event-Driven, MicroKernel, Stream-Based, and more.
What is Software Architecture?
Software architecture is the process of defining the high-level structure and organization of a software system. It involves identifying and selecting the right components, deciding how they should interact with each other, and determining how they should be organized to achieve specific goals. The goal of software architecture is to create a system that is maintainable, scalable, and secure, and that can meet the needs of users and organizations over time.
Why do we need Software Architecture?
A robust architecture provides a solid foundation for building software that meets the needs of users and stakeholders. It ensures that the system meets its functional and non-functional requirements, such as performance, security, and reliability. With a well-designed architecture, developers can build software that is easy to modify and extend, making it easier to adapt to changing business needs.
Software architecture is also essential for managing complexity. As software systems become more complex, it becomes challenging to understand how different components interact with each other. A well-designed architecture provides a high-level view of the system, making it easier to understand its structure and operation. This, in turn, helps developers to identify potential issues and make informed decisions about how to modify the system.
How do we Document Architecture? We use 4C Model.
Context Level
At the highest level, the Context level, we describe the system’s external environment, such as users, other systems, regulations, etc. This level provides a high-level overview of the system’s purpose and its relationship to the external world. It helps to identify the stakeholders who will interact with the system and the factors that will influence its design and development.
Containers level
The next level is the Containers level, which describes the runtime environment of the system, such as servers, databases, or message queues. This level helps to identify the major technology choices and deployment decisions. It provides an understanding of the physical infrastructure that will support the system and the tools and resources that will be required to deploy and maintain it.
Components level
The third level is the Components level, which describes the major functional building blocks of the system. This level helps to identify the modules, classes, or functions that make up the system. It provides an understanding of the system’s functionality and the relationships between its different components.
Code level
Finally, the Code level is the lowest level, which describes the actual code and how it implements the components. This level provides a detailed understanding of how the system works and how its different components interact with each other. It is essential for developers who will be working with the code to have a clear understanding of how it is structured and how it works.
Using the C4 model, software architects can create diagrams and written documentation that describe each of these levels, providing a comprehensive view of the system’s architecture. This approach helps to identify potential issues and trade-offs, as well as facilitating scalability, maintainability, and adaptability. By documenting the architecture in this way, developers and stakeholders can have a clear and easy-to-understand view of the system, making it easier to modify and extend as business needs change.
Here are the 12 Software Architecture Styles Software Engineer Should Know
1. Client Server
The client-server architecture is a model in which the client, a user or an application, sends a request to the server, which in turn responds with the requested data or service. The client and server can be on the same machine or on different machines connected through a network.
The client is responsible for initiating communication with the server and sending a request. The server, on the other hand, listens for incoming requests from clients, processes them, and returns a response.
Advantages of Client-Server Architecture
Scalability: Client-server architecture is highly scalable, as it allows multiple clients to connect to the same server and share resources.
Security: Client-server architecture provides better security than other network models, as the server can control access to resources and data.
Reliability: Client-server architecture is highly reliable, as the server can provide backup and recovery services in case of failures.
2. Layering
It’s a common way to design complex software systems, and it involves breaking down the system into layers, where each layer is responsible for a specific set of functions. This approach helps to organize code and makes it easier to maintain and modify the system over time.
A typical layering architecture consists of three main layers: presentation, business logic, and data access.
Presentation Layer: The presentation layer is responsible for displaying information to the user and gathering input. This layer includes the user interface and any other components that interact directly with the user. The user interface is what the user sees and interacts with, such as buttons, text boxes, and menus. The presentation layer also includes any logic related to the user interface, such as event handlers and validation.
Business Logic Layer: The business logic layer is responsible for implementing the business rules of the application. This layer contains the code that processes and manipulates data, as well as any other application logic. The business logic layer is where the magic happens, so to speak. It’s where the software performs calculations, makes decisions, and carries out tasks. This layer is where the software really earns its keep.
Data Access Layer: The data access layer is responsible for interacting with the database or other external data sources. This layer contains the code that reads and writes data to and from the database. The data access layer is where the software retrieves data from the database, makes changes to the data, and saves the changes back to the database. This layer is critical to the functioning of the software, as it enables the software to store and retrieve data.
3. Pipe and Filter
Pipe and Filter Architecture is a design pattern that allows software systems to process data by separating the processing tasks into multiple independent components. This architecture is particularly useful for systems that need to handle large amounts of data, as it can help to improve performance, scalability, and maintainability.
The Pipe and Filter Architecture is based on the idea of a pipeline, where data flows through a series of processing steps, each of which performs a specific task. Each processing step is implemented as a separate component, or filter, that accepts data as input, performs some operation on the data, and produces output data. The output data is then passed on to the next filter in the pipeline.
The filters in the pipeline are independent of each other, which means that they can be developed, tested, and deployed separately. This makes it easy to add new filters to the pipeline or modify existing ones without affecting the rest of the system.
Benefits
Scalability: The architecture can be scaled horizontally by adding more filters to the pipeline, which allows the system to handle larger amounts of data.
Performance: The architecture can be optimized for performance by parallelizing the processing of data across multiple filters.
Maintainability: The architecture promotes modularity and separation of concerns, which makes it easier to maintain and update the system over time.
4. Master-Slave
Master-Slave architecture is a design pattern used in distributed systems, where one node (the master) controls one or more nodes (the slaves) to perform specific tasks. The master node is responsible for distributing the workload across the slaves and for coordinating their activities. The slave nodes do not have the same level of control as the master node and only perform tasks that are assigned to them by the master.
Benefits
One of the most significant advantages is that it allows for the efficient distribution of workload across multiple nodes. This helps to reduce the load on any one node and ensures that the system can handle large amounts of data and traffic.
Another advantage of using a master-slave architecture is that it provides fault tolerance. If one of the slave nodes fails, the master node can redistribute its workload to the other slave nodes. This ensures that the system can continue to function even if one or more nodes fail.
5. MicroKernel
MicroKernel architecture is a software design pattern that allows developers to build more modular and flexible systems. It separates the core system functionality from additional features, which are implemented in separate modules. The core functionality of the system is implemented in the MicroKernel, a minimalistic core system that provides only the most essential services required to run the system. It is plug and play concept.
Example:
Let’s consider the example of an e-commerce website. The MicroKernel would provide essential services such as handling user authentication, managing user sessions, and processing payments. Additional features, such as product recommendations, user reviews, and social media integration, would be implemented in separate modules.
If the website wants to add a new feature, such as a loyalty program, it can be developed and added as a separate module without affecting the core functionality of the system. This modularity makes it easier to add new features or remove existing ones without affecting the core system functionality.
Furthermore, if the website wants to customize its system to meet the specific needs of different users, it can choose the modules it needs for each user. For example, a user who frequently buys electronics can be provided with a module that recommends electronic products. On the other hand, a user who frequently buys cosmetics can be provided with a module that recommends cosmetic products.
Finally, if the website wants to scale its system to handle more users or changes in hardware, it can easily add or remove modules as needed. This scalability makes it easier to adapt the system to changes in user requirements or changes in the underlying hardware.
6. DDD (Domain Driven Design)
At its core, DDD is a way of thinking about software architecture that emphasizes the domain or problem space of a project. This means that developers focus on the business logic of the software, rather than just the technical implementation.
In practice, this means that developers start by understanding the domain they are working in and break it down into smaller, more manageable parts. They then use this understanding to create a domain model, which is a representation of the different entities within the domain and how they interact with one another.
Once the domain model is created, developers can use it to guide the rest of the architecture of the software. This includes creating bounded contexts, which are areas of the software that are defined by a specific language and context, and aggregates, which are collections of related entities that are treated as a single unit.
7. Component Based
In software engineering, component-based architecture (CBA) is an approach to software design and development that emphasizes the use of reusable software components. The idea behind CBA is that software development can be made more efficient and effective by breaking down complex systems into smaller, more manageable components.
What is a component?
A software component is a modular, self-contained unit of software that can be reused across different systems. A component typically has a well-defined interface, which specifies how other components can interact with it. This interface includes information about the component’s inputs, outputs, and behavior.
Components can be classified into different types based on their functionality, such as user interface components, data access components, and business logic components. Each type of component has a specific role in the software system and can interact with other components through their interfaces.
8. SOA
SOA is an architectural style that aims to create modular, reusable services that can be easily integrated with other services to create a larger system. In this approach, services expose their functionality through interfaces, which can be accessed by other services or applications.
At its core, SOA is about building software by breaking it down into smaller pieces, or modules, that can be reused across different applications. This modular approach allows developers to focus on building specific pieces of functionality and then integrating them with other pieces to create a larger system.
Core Components of SOA
Service Provider: The service provider is responsible for creating and exposing services to the outside world. These services can be used by other services, applications, or end-users. For example, a payment processing service provider might create and expose a service that allows other applications to process payments.
Service Registry: The service registry is a directory of available services that can be accessed by other services or applications. The service registry provides information about the service, such as its name, location, and interface. For example, if an application needs to process payments, it can use the service registry to find the payment processing service and access its interface.
Service Requestor: The service requestor is responsible for consuming the services exposed by the service provider. This can be done by using the service registry to find the appropriate service and then invoking its interface. For example, an application might use the service registry to find the payment processing service and then use its interface to process payments.
9. Monolithic
Monolithic architecture is a software design pattern that has been around for decades. It’s a way of structuring an application as a single, cohesive unit, rather than splitting it up into individual, smaller components.
In a monolithic architecture, the entire application is built as a single, self-contained unit. All of the code and dependencies are packaged together, so the application can be deployed and run on a single server.
This makes it easy to develop and deploy the application, since everything is in one place. It also makes it easier to scale the application horizontally, by adding more servers.
Advantages of Monolithic Architecture
One of the biggest advantages of monolithic architecture is its simplicity. Since everything is contained in a single unit, there are fewer moving parts to worry about. This makes it easier to develop, test, and deploy the application.
Another advantage is that it’s easier to maintain and debug a monolithic application. Since everything is in one place, it’s easier to track down issues and fix them.
Disadvantages of Monolithic Architecture
One of the biggest disadvantages of monolithic architecture is that it can be difficult to scale the application vertically. Since everything is running on a single server, there’s a limit to how much traffic the application can handle.
Another disadvantage is that it can be difficult to adopt new technologies and languages in a monolithic application. Since everything is packaged together, it can be hard to update individual components without breaking the entire application.
10. Microservice
Microservice architecture is a style of software architecture that structures an application as a collection of small, independent services that communicate with each other over a network. Each service is focused on a specific business capability and can be developed, deployed, and scaled independently of other services in the system.
The main idea behind microservice architecture is to break down a large, monolithic application into smaller, more manageable services. This approach brings several benefits, such as improved scalability, increased flexibility, and quicker time-to-market for new features. With a microservice architecture, each service can be scaled independently, making it easier to handle traffic spikes or changes in demand. Developers can also modify or add new services without affecting other parts of the system, which speeds up the development process.
Challenges of Microservice Architecture
Despite the benefits of microservice architecture, it also introduces additional complexity. One of the biggest challenges is managing inter-service communication. Services need to be able to discover each other and communicate effectively, which can be difficult to do at scale. Load balancing and fault tolerance are also more complex in a microservice architecture.
Another challenge is ensuring that each service has its own data store. In a monolithic application, all data is typically stored in a single database. With microservices, each service should have its own data store to ensure that changes to one service do not affect other services in the system. This can lead to increased complexity in data management and synchronization.
Best Practices for Microservice Architecture
To ensure the success of a microservice-based system, developers should follow best practices for designing and implementing microservices. Some of these best practices include:
1. Design services that are loosely coupled and highly cohesive, with clear boundaries and well-defined interfaces.
2. Use containerization technology, such as Docker, to package and deploy each service as a separate container. This allows for easy scaling and deployment of individual services as needed.
3. Implement effective monitoring and management tools to ensure that the system is running smoothly and to detect and address issues quickly.
4. Use a service mesh, such as Istio, to manage inter-service communication and load balancing.
5. Implement a continuous integration and deployment (CI/CD) pipeline to automate the testing and deployment of microservices.
11. Event Driven
Event Driven Architecture (EDA) is an approach to designing software systems that enables rapid and efficient communication between different components or services. In this paradigm, different software components communicate with each other using events, rather than through direct requests or responses.
In EDA, events are generated by different components of a software system, such as a user interface or a backend service. These events are then broadcast to other components of the system, which can subscribe to them and act on them as needed.
For example, consider a simple e-commerce application. When a new order is placed, the order processing service can generate an “order created” event, which is then broadcast to other services such as inventory management, shipping, and billing. Each of these services can then process the event and make updates to their respective systems.
Benefits of EDA
One of the key benefits of EDA is its ability to decouple different components of a software system. When different components communicate through events rather than direct requests, they become less dependent on each other. This makes it easier to change or update individual components of the system without affecting the rest of the system.
Another benefit of EDA is its scalability. Because events are broadcast to multiple components of the system, it is possible to process large volumes of data and transactions in parallel. This makes it easier to handle high traffic and spikes in demand.
Challenges of EDA
While EDA has many benefits, it also has some challenges. One of the main challenges is managing the complexity of event-driven systems. Because events can be generated and consumed by many different components, it can be difficult to track and debug issues that arise.
Another challenge is ensuring that events are processed in the correct order. Because events can be generated and processed asynchronously, it is possible for events to be processed out of order. This can cause issues such as data inconsistencies or incorrect calculations.
12. Stream Based
As software development becomes more complex and demands greater scalability, traditional architectures are becoming less and less effective. Stream-based architecture is emerging as a promising alternative that enables developers to build systems that can handle massive amounts of data in real-time.
At its core, stream-based architecture is based on the principles of event-driven programming. Instead of processing data in batches, stream-based systems process data as it is generated in real-time. This allows developers to build systems that can respond to changes in data with minimal latency.
Benefit of Stream-Based Architecture
One of the key benefits of stream-based architecture is its scalability. Because data is processed in real-time, stream-based systems can handle massive amounts of data without the need for complex batch processing pipelines. This makes it possible to build systems that can process millions of events per second, making it ideal for use cases like sensor data processing, financial trading, and online advertising.
Another benefit of stream-based architecture is its flexibility. Because data is processed in real-time, it is possible to build systems that can respond to changes in data with minimal latency. This makes it possible to build complex, event-driven systems that can adapt to changing business requirements. For example, in an e-commerce platform, stream-based architecture can be used to track user activity in real-time and respond with personalized recommendations and promotions based on the user’s browsing and purchasing history.
Furthermore, stream-based architecture can provide significant cost savings. Traditional batch processing pipelines require expensive hardware and complex software infrastructure to manage the data processing. On the other hand, stream-based systems can be built on inexpensive commodity hardware, making it much easier to scale and maintain.
Finally, stream-based architecture is highly fault-tolerant. Because data is processed in real-time, it is possible to build systems that can automatically recover from failures without the need for manual intervention. This makes it possible to build systems that can operate at scale with high levels of reliability, reducing the risk of data loss or system downtime.
Conclusion
In conclusion, software architecture is critical for building successful software systems that meet the needs of users and stakeholders. It provides a blueprint for designing and developing software systems, ensures that the system meets its functional and non-functional requirements, facilitates adaptability, and helps manage complexity. Therefore, it is essential to invest time and resources in designing a robust architecture at the beginning of a software development project. Hope you enjoy and Happy Learning.
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