Microservices vs Monolith. Сhoosing the Right Architecture for Your Project
Table of contents
Two types of development architecture are prominent, microservices and monolithic. The monolithic structure, which has been existent for a long time, was natural selection. But as soon as microservices made headway into the industry, the developers are faced with a tough decision, which had both technological and philosophical underpinnings. The debate between monolithic and microservices is an ongoing process, and new aspects are added to their impact and utility regularly. In this article, we will explore the significant differences between monolithic vs microservices, along with identifying a few examples of both.
Understanding Monolithic vs Microservices Architecture
An application or software is limited to the code; there are many other aspects that help create an application and give its true form. Besides the code, we must understand the business logic, database, app server, clients, etc. All these aspects must join together to build a functional application or software. Now, when it comes to implementing the structure, the developers can take two routes. One is where everything is connected with a single string. Think of a house cut out from a single stone, and every room is connected to the other with only a single point of entry, and you have to cross through one room to reach the next one. Also, think about the wiring and plumbing in this house. To modify the wiring in one room will have to be done from the single entry point, which will also induce changes in the other room’s wiring.
That is the monolithic structure you can understand in simple terms. Everything is connected and dependent on each other. For software or application, the entire codebase is unified, we have a single executable library with multiple modules for features, but they are also connected. In contrast, the microservices architecture is a segregated structure wherein every aspect of application or software is built with single independent modules, leading to different databases. Here, every module is different from each other, but they form a unified and fully functional solution when joined together. Each of these services has a different business goal and is built with the same in mind.
Taking the same wiring example, a microservices approach would install a different and independent wiring system for every room in the house. Hence, any requirements to change the wiring in one room won’t be dependent on any other room. And any changes in one room won’t affect the wiring system in the other room. Microservices has gained prominence in the mobile age as the developers are tasked with accessing the data via API access doing away with the legacy data exchange system. Due to this, we see a migration from monolithic to microservices architecture. Another one of the microservices architecture examples is lego construction blocks. We can create single and independent structures and join them together to build a bigger structure, wherein all the single structures and the bigger structure work as standalone systems.
Monolithic architecture
A monolithic architecture is a traditional form of building software wherein the entire structure works as a single autonomous unit. It has a single codebase with various modules, depending on the business complexity and its technical features. Monolithic structures have a robust system to handle all the operations and functions as it is serving multiple clients, leading to a vertical stack architecture development. These are non-distributed systems that exist as a single body, and the databases and the application functions are dependent. We can also say that a monolithic structure is a self-contained entity projecting a linear buildup from scratch. The singularity of this structure makes for a large codebase coupled with a common business logic, which has its advantages and disadvantages.
Pros and Cons of Monolithic
Pros:
- Easy to Monitor: As per the monolithic definition, the applications are built with a single structure. This means observing the effects of the changes in the code, identifying the code rebalancing, and even picking out the bugs from the codebase. Monolithic applications can also benefit from detailed troubleshooting achieved via two types of performance monitoring systems, Infrastructure and Application. Infrastructure performance monitoring identifies the individual components of an application to know how they work together. It takes into account operating systems, servers, and storage components. Application performance monitoring helps identify and solve the performance issues in the software, which is an essential aspect in the microservices vs monolithic approach. This is beneficial to ensure that the entire application structure complements its performance.
- Organized Code Deployment: Deploying an application or software built with a monolithic structure is easy and streamlined. The developers need to upload on a single code package, and if there are any performance issues, they can make changes or roll back the previous changes to ensure the desired performance. The speed of changes and their effect is fast, not letting the developers wait for a long time to implement the changes, which is not easy to obtain in a microservices architecture.
- Close-Knit Communication and Response: Another amazing thing about monolithic application structure is fast communication. In monolithic vs microservices architecture comparison, the near-instantaneous communication is the result of a self-sustained and close-knit architecture. Faster communication can also bring more speed and efficiency into the application.
- Integrated Development Environment: Since a monolithic structure resembles a unified platform, it is easier to set up different development environments for different structures. This makes it easy to identify the right IDE for software architecture.
- Simple Testing and Deployment: Because they work as a single unit, the software, and applications built on monolithic architecture are easy to test and debug. With code dependency, we can easily judge the changes of editing one stream of code on the others, which reduces the time to test and deploy the application.
Cons:
- Not Easy to Scale: As per the monolithic definition, these structures are not easy to scale because as the codebase grows, making changes in the system requires a lot of work and time. The code entanglement increases with the application’s size, and isolating the services at that point to upgrade the features or scaling a single function gets more complex. This is one of the reasons why developers are inclined to choose the microservices approach in the microservices vs monolithic debate. Horizontal scaling in a monolithic application is a difficult task to implement.
- Difficulty in Comprehending: When the entire code base evolves and grows, the developers will face issues with identifying the code for a specific feature. At a time when the application is still evolving, it is fairly easy to filter out the code for a particular function. But at a time when the code base is large, looking for a single set of code is like finding a needle in the haystack. Even if you manage to make changes, the effects of the change on other aspects is also a difficult task.
- Full Redeployment: Every single and minor change in the codebase warrants a redeployment of the entire architecture. Imagine changing the background color of the application, but to see the change, you will have to initiate redeployment of the entire codebase. When multiple people are working on a single project, this issue reduces the team’s agility and increases the delivery time.
- Not Easy to Implement New Technologies: Monolithic architecture is a solid and rigid structure with less scope of modifying and implementing new things into the system. Due to this, it is cumbersome to integrate new technologies into the architecture. Doing so means implementing a huge cost and spending time on the same. On the other hand, not integrating these technologies means that the organization won’t be able to compete in the market.
- Discontinuous Delivery and Deployment: To ensure a seamless deployment and delivery, the code must render faster and seamlessly. Such a setting is not easy to source in a monolithic architecture because every incremental update will take time and effort.
Microservices Architecture
In monolithic vs microservices, the latter is about dividing the application or software into a few smaller and interconnected aspects. We can say that every module in such a setting is an application in its own. They have their unique hexagonal architecture and have their separate business logic. Also, every module also has its own database schema, which further becomes one of the best benefits of microservices. Building microservices-led systems is akin to a distributed and decentralized structure. Even though the components of an application built with a microservices approach are self-contained, they are usually joined together to power up a single software or application.
Pros and Cons of Microservices
Pros:
- Developer-Friendly: In the debate on monolithic vs microservices, the latter will always come on the top in terms of ease of use and overall functionality efficiency. A microservices-based approach is split into small parts. This makes it easier for the developers to understand and identify each of the modules and rest assured that none of the changes in one module will have an effect on the others.
- Isolated Modules Development: Another one of the advantages of microservices is parallel development. The isolated modules, which do not affect the functioning of other modules, can be developed, edited, altered separately. There is minimal overlapping, and if there is any, it is easier to identify and adjust. In the end, in terms of time consumption in the monolithic vs microservices approach, microservices is faster and better. That’s not all. Since the development time improves, you can also get faster updates and deliver the tasks with speed.
- Isolated Bug Finding and Fixing: Not just with development, but the microservices architecture makes it easier to find the bugs and fix them without inciting any changes in other sets of code. And if there are any bugs, they won’t affect the other modules as there is little to no overlapping.
- Reusable Components: While building microservices architecture, you can also reuse the same modules originally built for one application on others too. For instance, if you have created a login module that has all sorts of login options.Including direct and social media logins via an API request, you can use the same module for another application that requires the same function. Due to this, the time to build and deploy the application decreases substantially.
- Better Extensibility: Taking our home wiring example once again. Suppose there is a break in the wire of one room, and the entire structure is built on monolithic architecture principles. To fix the wire in one room, you will have to change it for all the rooms. However, the microservices architecture does not require changing the wires of all the rooms. You only need to work on changing the wires of that room, which has faulty wiring. The same goes for the codebase in a microservices architecture. In addition to this, you can also change the technologies in a microservices system, either for the entire software or for individual components.
Cons:
- The Distributed System is Complex: While the implementation and deployment of this structure are easy, its development and configuration is a difficult task. Moreover, the database for every module is different, which further increases the complexity levels surrounding database maintenance and infrastructure management.
- Testing is a Painstaking Task: For testing a microservices application, you need to test all the modules separately. Where the system of testing is improved, but you can only imagine the number of tests you need to run for every different module. In microservices vs monolithic, testing is difficult because the modules might have been built with different frameworks, languages, and approaches. So, to test the modules, you must identify these patterns first.
- Network Complexity: Networking here implies how each of the modules interacts and connects on a micro and macro level. Where micro-level interactions are sort of automated, macro-level networking is difficult to comprehend.
Examples of When You Should Use Monolithic Architecture
When you want to build single-page applications like for an eCommerce store, it is beneficial to use a monolithic architecture structure and when the application size is small. Secondly, in case your application does not require a lot of updates, and there is no need to hire a big team for the same, a monolithic architecture is the best bet. It is possible to use a monolithic architecture to build a large-scale application because you can also migrate to a microservices architecture when the app has to be scaled.
Examples of When You Should Use Microservices Architecture
Suppose the application and software you are building has complex underpinnings and requires cross-platform development practices, not to mention that it will get a heavy data response. In that case, you need to go with a microservices architecture. As we have understood above, in monolithic vs microservices, the former is a rigid structure; it does not need a big team. But if you need a big team to work on the project, go with the microservices architecture approach. A few of the microservices architecture example includes Netflix, Facebook,
Conclusion
In a nutshell, choosing between monolithic vs microservices is easier given that you have set your requirements from the get-go. If the application you want to build is not data-intensive, will cater to a small group of people and does not require a big team, go with monolithic. In contrast, a Microservices approach is relevant when you want to build a scalable application that offers complex functionalities that can be built with the help of a big team.
