Monolithic architecture is one of the most prevalent software designs. In software engineering, the term "monolithic model” refers to a single, indivisible unit. The idea behind monolithic software is that all of the parts of an application are put together into a single program like the database, the client/user interface, and the server, all in a single code base.
The most important benefit of the monolithic architecture is how simple it is. If you’re just starting out small with your software development, monolithic is easier to test, deploy, debug, and keep an eye on. All of the data is kept in one database, so it doesn't need to be synchronized.
Monolithic Design Can’t Keep Up With the Development Needs of Agile teams
Monolithic architecture works best for simple applications because as a single small deployable unit, they are easy to build and maintain. But things do not stay simple all the time.
As the size and complexity of the app grow, problems start to appear. It becomes harder to make changes to the code without feeling concerned about its cascading effects. Changes to one module can cause other modules to act in unexpected ways, which can cause a chain of errors.
Because of how big the monolith is, it takes longer to start up, which slows down development and gets in the way of continuous deployment. Agile teams want to ship new changes quickly and iteratively in short cycles (called sprints) which is difficult to achieve with complex applications built as monoliths. Collaboration is hard because of the complexity of a large code base compressed as a single unit
Problems with Monolithic Architecture
Statista's 2021 research shows that “only 1.5% of engineering leaders plan to stick with a monolithic architecture.” With the demanding need for software expansion, the rise of mobile devices, and the cloud, monolithic applications are not going to help. Worse, since everything in a monolithic architecture is tied to a single codebase, it can be hard to test specific functions or components because it is difficult to separate them, leading to vastly higher costs.
Monolithic Architecture Scalability Issues
If a monolithic application becomes popular and its user base grows, it can become difficult to scale the application to meet the increased demand. All of the application's features are in a single codebase, so adding more resources requires deploying a whole new version of the application.
Lack of modularity
Because a monolithic application is a single, cohesive unit, it can be difficult to reuse specific parts of the application in other projects. This can make it hard to update or fix individual parts of an app without changing the whole thing.
When a new version of a monolithic application needs to be released, it can take a long time because the whole application needs to be deployed again, even if only a small part of it has changed.
Difficulty in identifying and fixing issues
When something goes wrong with a monolithic application, it can be hard to figure out why because all of the functionality is in a single codebase. This can make it challenging to fix issues and deploy fixes quickly.
Monolithic applications often have tight coupling between different parts of the codebase, which means that changes in one part of the application can have unintended consequences in other parts of the application.
Monolithic Architecture Inflexibility
Monolithic architecture can be hard to change because it doesn't make it clear which parts of an application are responsible for what. This can make it hard to change or update one part of the application without possibly affecting other parts.
Monolithic applications can become complex over time as they grow and more features are added. This can make it difficult for new developers to understand how the application works and contribute to it.
Testing and deployment challenges
Testing and releasing a monolithic application can be hard because it can be difficult to test each part of the application separately. This can make it difficult to identify and fix issues before deploying the application.
The Emergence of Microservices
As software systems got more complicated and had more needs, it became clear that a single-piece architecture couldn't handle everything. As a result, new approaches, such as microservice architecture, have been developed and implemented. However, monolithic architecture is still commonly used, especially for smaller and less complex systems.
Again, taking insights from Statista's 2021 research, 81.34% of businesses already use microservices, and 17.34% are planning to make the switch.
Microservices, unlike monolithic systems, are designed to scale with changing market demands. Modern businesses are moving away from monolithic systems to microservices so that they can stay competitive.
What is a monolithic architecture?
Monolithic architecture is a traditional software design approach where an entire application is built as a single, interconnected system. In this structure, all components and functions are tightly integrated, making it challenging to modify or scale specific parts independently. It contrasts with microservices architecture, which divides the application into smaller, loosely coupled, and independently deployable components.
What are microservices?
Microservices are a software development approach where an application is divided into small, independent components that perform specific tasks and communicate with each other through APIs. This architecture improves agility, allowing for faster development and scaling. It simplifies testing and maintenance by isolating components. If one component fails, it doesn't impact the entire system. Microservices also align with cloud technologies, reducing costs and resource consumption.
What are the Disadvantages of a monolithic architecture?
Monolithic architecture has several disadvantages. It faces scalability challenges, as scaling the entire application can be inefficient and costly. Modifications and updates are complex and risky, given their broad impact. Monolithic apps demand substantial resources and can hinder development speed due to collaboration difficulties. Furthermore, they are susceptible to single points of failure, where issues in one part can disrupt the entire application's functionality, making them less resilient.