For years, the majority of apps have been developed with a monolithic architecture. It was the standard in app development, but as technologies have moved forward, it has become outdated.
Netflix is a pioneer in switching from a monolith architecture to cloud-based microservices architecture as its infrastructure couldn’t keep up with the rapidly growing demands. Netflix has set a trend in the market, and more and more companies have discovered that microservices offer greater scalability, agility, and flexibility, so why go back to monolithic architecture? Still, it hasn’t vanished, as monoliths continue to be the foundation of many software applications.
At IntelliSoft, we know a great deal about both types of architecture, as our 16 years of experience in software development have helped us learn about the pros and cons of both. If you want to learn about monolithic vs. microservices pros and cons, and what type of architecture to choose for your company, continue reading this guide.
Table of Contents
What are Microservices?
Microservices are a new version of Service-Oriented Architecture (SOA). These are small, independently deployable services modeled around complex applications. Microservices carry out every app’s process as a separate service.
Imagine microservices as small building blocks of an application that run on their own processes simultaneously and communicate with mechanisms like HTTP resource API. Microservices have one considerable advantage: They are technology and language-agnostic. It means that these apps can be programmed in any language, allowing developers to use their skills to the maximum advantage with no need to experiment.
With microservice architecture, each service covers its own scope and can be deployed, updated, and scaled independently. Now, let’s take a look at the pros and cons of microservice architecture.
Benefits of microservices architecture
- Independent components
Microservices have an autonomous nature consisting of independent components that can be deployed and updated separately. This autonomy also allows to prevent bugs and issues with the entire system. Even if a bug happens in one microservice, it affects only a specific server, not an entire application. Since these microsystems are independent, it is also easier to add new features.
- Better scalability
One of the main advantages of microservices is that they can be scaled independently. You don’t have to scale an entire application when there’s no need for it, you need only scale a specific element. Moreover, there are no limits to scalability with this type of architecture, so it can fit your growing requirements.
- Easier to maintain and test
The more small components there are, the easier it is to maintain an architecture. Moreover, microservices allow teams to experiment with the feature and roll back if something doesn’t work. It makes adding new features and updating code a piece of cake.
- Isolation of services
Since all the services in microservice architecture work independently, any error or fault affects only a specific service, not the entire application. That’s why adding new features and experimenting without the fear that it will break down the app is easier.
- Flexibility
Microservices are tech agnostic. It doesn’t matter which technology you choose at the start, so developers are free to decide. Let’s say your team of developers is highly skilled in one language, so why not build microservice architecture using this language since there are no strict requirements?
Disadvantages of microservices architecture
- Very complex
Microservices is a distributed system of independent components, all of them needing a connection to work properly. Thus, you need to choose and set up these connections between all databases and modules. Moreover, independent services within an application need to be deployed independently.
- Difficult to test
Software testing of microservice architecture is challenging, to say the least. Even though deployment may be fast, it is difficult to recreate environments for testing and test all independently deployable components separately.
- System distribution
All connections between modules and databases have to be handled extra carefully. Moreover, your app will definitely grow, and the number of services will grow as well. Managing all these services and their dependencies can be overwhelming.
- Cross-cutting concerns
When developing microservices architecture, keep in mind that there are several cross-cutting concerns. They include configuration externalization, logging, metrics, and health checks.
What is a Monolith?
For years, monoliths have been a traditional way of building apps. Monolithic architecture is everything merged together, hence the name. It is built as a single unit with a large block of codes with multiple modules. They are tightly connected with each other like a huge solid rock.
Monolithic software is a single deployable binary that encapsulates business logic, application, user interface, and other distinct components. It uses the same programming language, a single environment, and a repository, and if there are changes in one of the components, it affects the entire app. Unlike in microservice architecture, all components of a monolith are tightly connected and interdependent.
Advantages of a monolithic architecture
- Less cross-cutting concerns
With monolithic architecture, there are fewer cross-cutting concerns. Since all the relevant data is in one place, it is easier to handle logging, cashing, and performance monitoring.
- Easy to develop
It is a standard, traditional way of building apps, so there are a lot of qualified engineers experienced in the development of monolithic applications. Moreover, all the code in monoliths is in one place, so it’s much easier to build upon.
- Seamless debugging and testing
Again, since all the code is in one place and your service has no dependencies, identifying the source of any issue is very easy. A monolithic app operates in one unit, so testing it is much faster than microservice architecture.
- Simple and fast deployment
Compared to microservice architecture, where you have to handle multiple deployments, you only have to handle one with a monolith. It saves you time and effort and puts monolithic architecture at an advantage.
- Reduced latency
When multiple services communicate with each other, it usually takes more time from taking action to receiving a result. Monolithic architecture comes with a lower latency.
Disadvantages of monolithic architecture
- Code complexity
You can build a monolith with no issues, but as your requirements change and start growing, it would be almost impossible to maintain a large database within one app and scale up. The code would become too complex as the monolith grows.
- New technology barriers
Monolithic architecture is a traditional way of building apps, and it usually doesn’t support cutting-edge technology because it would require rewriting the entire software.
- Interdependent components
All components in a monolith are highly interdependent, so it’s challenging to implement any new features or alter the system with such a high coupling. Any changes in the code would affect the entire system, which makes it almost impossible to experiment with new features.
- Limited scalability
Unlike microservice architecture, where you can scale each component separately, it’s impossible with a monolith. In this case, you would need to scale up the entire application, which is much more complicated.
- Slow development
To develop a monolithic application, developers have to work from the same codebase, which can seriously affect the development speed. They should also pay more attention to testing as a single error can affect the entire application.
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Microservices vs Monolithic: a Detailed Comparison
Now that we know about the strengths and weaknesses of microservices and monoliths, it’s time to compare them and help you decide which one to choose for your app development. We will analyze their performance, scaling, deployment, security, cost, and collaboration.
Performance and scaling
The more distributed a system is, the more scalable it becomes. That’s where microservices architecture gets the point – it is easy to scale both as demands grow and as the development teams expand.
With microservice architecture, you can scale specific parts of the app separately, so you have full control over the process. You can see how the app performs at any development stage as you scale a separate part.
Compared to microservices, monolithic architecture is at a disadvantage here. Unfortunately, it is difficult to scale up because of how tightly all components are connected. You have to scale up the entire app, which takes a lot of time and effort and gets pretty expensive. What’s more, adding new features to the app makes the codebase so large that it can become almost unmanageable to scale the application.
Nothing is as perfect as it seems with microservices, though. Unless you have other means to track all of its services, it can become too overwhelming to keep track of all of them. Since microservices’ elements rely on APIs, they are vulnerable to third-party outages and can have performance issues if the APIs are not properly designed. That’s not an issue with a monolith because all calls are local.
Deploying
When it comes to deployment, there’s no real winner here. Microservices architecture allows for individual services and their upgrade deployment without the need to deploy the entire app. It’s possible to deploy one component at a time, making the process smooth and fast. However, it’s only possible if the engineers can handle the complexity of microservice architecture. If not, it can become too challenging and lead to errors and delays.
Monoliths operate from a single codebase, so there’s nothing to get overwhelmed with. They are easier to build and deploy, but developers can’t alter a specific piece of the app. You either deploy the entire app and hope for the best, or have to deal with bugs and unexpected app behavior.
Security
Monolithic architecture loses a point when it comes to security. Since all of its components are tightly interconnected, the entire app is at risk if anything happens. Yes, protecting a small monolith with a firewall is possible, but as the code grows and becomes larger, it becomes even more vulnerable.
Microservices are less prone to security risks as the threat gets spread out across all individual services. Even if something happens to one component, the rest will be protected because they are not closely connected to it. Thus, you don’t have to worry about the entire app as it will continue to function. However, you need to pay attention to the security of APIs and ensure that all authentication protocols and encryption are in place.
Cost
The cost of both types of architecture depends on your needs and requirements and how much you are willing to pay. Even though monolithic architecture requires lower upfront payments, it is more expensive to scale and develop. Microservices are more expensive at first, but cheaper to scale, and are a more cost-effective option in the long run.
Ops and collaboration
To work with a distributed microservice architecture, you also need to distribute your team. Every team should be responsible for a specific service and its maintenance, deployment, programming, testing, and so on.
Even though each team is responsible for an independent aspect of the architecture, they still need to communicate with each other, just as services do. That is your task as a leader, to ensure that there are no obstacles to this communication and that all teams understand their responsibilities and tasks.
With a monolith, the situation is quite different. All teams are working from the same codebase and collaborating along the way. The thing is, the structure of a monolith is not always the same as the structure of an organization. It can lead to confusion, inability to manage teams properly, and misunderstandings within the organization.
How to make a choice between the two?
It seems that there’s no real winner here, so how, then, do you choose the type of architecture for your project? Do not worry, these tips will help you decide. Let’s take a look at them.
4 reasons to choose a monolithic architecture
- You’re building a simple app: Monolithic architecture is a great fit for simple applications that do not require incredible scalability, business logic, and flexibility.
- You need lower software latency: In monolithic architecture, there are fewer network connections, so all data packets travel from one destination to another super quickly. All communications there are realized within a single instance of an app.
- You need to launch the app quickly: If you want to develop and launch the app as quickly as possible, a monolith is a perfect choice. It uses a single code base and works well if you do not plan to grow and scale up the app.
- Your monolith is modular: If you already have a monolithic system that is unified, but the code is divided into features modules and well-organized, there’s no need to switch to microservice.
4 reasons to choose microservices architecture
- You want to build a complex, scalable app: With microservices, scaling up and adding new features is a piece of cake. You can scale individual components, test new features, and don’t worry that it will affect the entire app. If you plan to develop a large application with a ton of features, modules, and user journeys, stick to microservice.
- You want to increase fault tolerance: Since modules are isolated from each other, it protects the system from failure. While you handle issues with one module, the rest of the application continues functioning.
- You plan to add new features constantly: Usually, adding new features to an application means redesigning the whole solution. You can build and deploy new features separately in each service with microservices.
- You want to implement several technologies: If you plan to add new features to each module and fear that they may contradict – it won’t happen with microservices. The isolation of modules allows you to add as many new features to modules as you wish.
When to migrate from monoliths to microservices
Yes, you can migrate from monolithic architecture to microservices, but it doesn’t necessarily mean you should. If you have a simple small app, don’t plan to scale it up, and your DevOps team works in new systems, rarely interacting with the monolith, then it’s better to stick to it.
However, it can be the case that a monolith can no longer meet your growing requirements. Still, it doesn’t mean you should completely change your architecture. You can experiment and break down your monolith into macroservices with the potential to be broken into microservices later.
This approach is called incremental: it allows your developers to adapt to changes and learn how to work with microservices one step at a time instead of jumping into it without any preparation. Moreover, with this approach, you don’t have to set any deadlines for migration. You can work at your own speed and take as much time as you need.
Conclusion
Choosing the type of architecture for your application cannot be easy. You can’t simply go for what others are choosing or what’s in trend right now. It should be a wise decision based on thorough research and consideration of your requirements and goals. Yes, a monolith is an established type with thousands of developers using it, but it’s not a one-size-fits-all solution. The same goes for microservices: they are incredibly flexible and scalable, but not every team can handle working with them. Therefore, make a choice based on your unique case, and if you have any questions or need a consultation, don’t hesitate to contact us.
