Monolithic architecture is the classic way of software development wherein all components are built as a single code and deployed as a single file. However, a new kind of architecture, microservices, has been gaining popularity among businesses. Essentially, businesses today have two broad choices to roll out technology stacks—either deploy a single platform that combines many functions or use microsystems to integrate discrete services from different vendors. This article explains the basics, pros, and cons of these two approaches and the key disadvantages of monolithic application architecture you should know.
Monolithic Architecture is the traditional, all-in-one structure for software applications wherein all aspects of software operate as a single unit. More often than not, a piece of software is a combination of different feature sets. In monolithic architecture, all software features exist in a single code base and are deployed as a single file. If any code updates are required, the developer has to use the same code base, make the required changes, and re-deploy the updated code. In a related article, we discussed scalable web application architectures that can host millions of users. Monolithic software applications can have the following components:
An e-commerce application is a good example of a monolithic approach. A single app authorizes the customer, takes an order, checks inventory, authorizes payment, and ships ordered products. Despite having different components/services, the app is built and deployed as one application for all platforms (i.e., mobile, tablet, desktop).
There are mainly two types of monolithic architecture:
Monolithic architecture is often compared to microservices architecture because of the latter’s many benefits for business-oriented APIs. Let’s understand what microservices architecture is.
A microservices architecture is an organizational approach to software development wherein software is composed of small, independent services that communicate through well-defined APIs. It is a distinctive method of developing software systems focussing on building single-function modules with well-defined interfaces and operations.
Microservices are built as independent services wherein each service is a separate codebase manageable by a small development team. These services can be deployed independently, and a team can update an existing service without rebuilding and re-deploying the entire application, as in monolithic architecture. Typical microservices architecture usually has the following components:
Microservices differ from monolithic architecture because they function as a loose collection of functionalities working together under a single application. Each service under an application may have its own database with a dedicated team working on it. While monolithic apps connect to a single database, each service in the microservices structure connects to its own database.
The two structures can be better understood with a practical example. A monolithic app may be a simple office suite software program in which an individual can download the entire application simultaneously. An example of a microservices app may be an online streaming platform with one microservice for onboarding new users, another for maintaining platform content, and another for recalling user preferences.
In fact, Netflix was one of the first online streaming platforms to use the microservices architecture. The platform struggled to keep up with the rapidly increasing demands of video streaming services. Hence, it migrated its IT infrastructure from private data centers to a public cloud. Though the term ‘microservices’ didn’t exist then, the platform won the 2015 JAX Special Jury award for its new infrastructure.
In light of these definitions, monolithic apps may seem simple and easier to handle. However, that is not always the case. We’ll now discuss some drawbacks of the same.
The disadvantages of monolithic apps primarily arrive from their all-in-one structure.
But does this mean that monolithic applications have no benefits at all? Not necessarily. Here are some ways in which monolithic apps prove to be beneficial.
Traditional monolithic architecture often results in large teams working on a single artifact. They tend to evolve into a situation where no single developer can truly understand the entirety of the application. Moreover, the repeated deployment of monolithic artifacts makes it difficult to achieve operational agility.
A microservices architecture provides a different approach to software development. Essentially, the monolith is disassembled into a set of independent services developed, deployed, and maintained separately. This has various advantages, such as:
Despite the disadvantages of a monolithic application, there are some business use cases where monolithic architecture is the right choice.
Most projects initially start as a monolith and then evolve into a microservices architecture. This may be because too many developers work on a single codebase, leading to frequent code conflicts, or because of the increasing risk of updates to one feature introducing bugs in another. Here are a few tips businesses can keep in mind during their migration process.
In this article, we covered the disadvantages of a monolithic application. Both monolithic and microservices approaches to software development have their pros and cons. A monolithic architecture is best suited for simple, lightweight applications. However, as the app grows, traditional architecture is bound to face problems and demand more time and effort. More often than not, a shift to microservices architecture will be required. That said, it is important to understand the monolith architecture since that is the basis for microservices architecture.