Microservices vs. Monolithic Architecture: Which One to Choose?
In today's hyper-competitive market, the optimal path for business development should be clear. In other words, you want to always keep up with the times or stay ahead. This means your developers and IT staff will constantly be learning new technologies and best practices. As they acquire new skills and adopt new software stacks, a number of decisions will need to be made.
One important decision is choosing between microservices architecture and monolithic architecture. If you make the right choice, you gain significant advantages. The wrong choice, and you'll find yourself in a constant struggle to keep your data center running smoothly.
Such a wrong decision can be a nightmare for your developers, regardless of whether they work on Java, JavaScript, Ruby, or .NET. It can also affect the entire application development process. Therefore, it is very important that those making such critical decisions understand what they are getting into.
So, what exactly are these architectures? Let's examine them and find out which one might be right for you.
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Criteria
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Microservices | Monolithic |
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Structure
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Breaks the application into small, loosely coupled, and independent services | Builds the application as a single, indivisible unit |
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Development
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Enables independent development and deployment of services | All components are interconnected, so they must be developed together |
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Scalability
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Individual components can scale as needed | The entire application must be scaled even when demand for only one feature increases |
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Technology Stack
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Each service can use its own technology stack | All components must use the same technology stack |
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Deployment
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Enables continuous deployment and integration | Updating requires deploying the entire application |
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Fault Isolation
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Failure in one service does not affect others | A single error can bring down the entire application |
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Performance
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High performance and speed due to lightweight services | Performance depends on the size and complexity of the application |
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Data Management
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Each service can have its own database | A single database is used for the entire application |
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Complexity
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More complex due to distributed system challenges | Less complex initially, but can become hard to manage over time |
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Development Speed
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Initially slower due to the need for careful planning | Initially faster due to simplicity |
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Modification
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Easier to update or add new features without disrupting other services | Updates or modifications may require changes to the entire system |
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Testing and Debugging
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Easier to test and debug individual services independently | Testing and debugging can be more complex due to application interconnectedness |
| Inter-service Communication | Services communicate via APIs, which can increase latency | Components communicate directly, usually resulting in lower latency |
Monolithic Architecture
We'll start with monolithic architecture because it's the simplest to understand. Why? Because monolithic architecture has been around for a very long time. In fact, monolithic applications are what most people understand when they hear the word "software."
Simply put, a monolithic application is one built as a single unit, although this doesn't necessarily mean it includes everything needed for the application to run. Let's break this down to better understand what's happening.
Yes, there are applications installed as standalone clients. Take the LibreOffice office suite, for example. This application does not depend on third-party programs or external services. Everything runs on the local client machine.
On the other hand, the WordPress blog platform requires the following:
- A database server
- A server-side application
- A client-side user interface
Each of these components is monolithic and works together to create a coherent whole.
Confused? Let's simplify by looking at it from a developer's perspective.
Suppose your company has deployed an in-house monolithic content management system. This system includes a database, a server-side application, and a client-side user interface. It runs flawlessly, and your employees depend on it every day.
However, at some point, developers want to add new functionality to the server component. To do this, developers would have to rebuild and redeploy the entire server application. While the end result might be worthwhile, the entire development process (design, development, QA testing, deployment) takes considerable time.
Microservices Architecture
Now let's look at microservices architecture. If a monolithic application is contained in a single block, microservices break it down into many much smaller and independent blocks. Each of these blocks performs a service function for the application, which then comes together as a cohesive whole.
One of the best examples of microservices architecture is containers.
You can deploy an NGINX server as a monolithic service. Install NGINX on a Linux server and you're ready to serve your websites. You can add a database by installing MariaDB. However, this type of deployment presents two major problems.
First, if you want to update your web server, you have to update every component as a whole—both the web server and the database. Second, this type of deployment may not be able to scale according to business needs.
The alternative is to deploy the web server as a set of microservices using containers. You can deploy an NGINX web server pod, a database pod, and then connect them using a network service and a storage volume within a Kubernetes cluster.
When scaling is needed, Kubernetes can automatically deploy additional NGINX and MariaDB containers in the cluster.
Besides scalability, one of the best features of microservices architecture is that if one service fails, another is deployed in its place. Thus, fault tolerance is built in. And since all components are deployed independently, the prospect of updates becomes much smoother. This is especially true for containers, where update-related downtime is virtually eliminated.
Which One to Choose for Your Company?
The answer to this question can be quite straightforward:
If your company requires high scalability, fault tolerance, and reliability, you should use microservices architecture.
If your company mainly needs client tools (installed on desktops) or you are not considering enterprise-level scaling, monolithic architecture will suffice.
A Caveat
A caveat here: microservices architecture is not easy to deploy. Kubernetes is complex on virtually every level. So, if you are interested in microservices architecture, you must be confident that your developers and IT administrators can handle it; otherwise, you'll be in a constant state of troubleshooting.
Additionally, resources are required for a successful microservices deployment. To truly benefit from the scalability of microservices, you need a data center with sufficient capacity to support such an architecture. Most often, this means deploying on a third-party cloud host like Amazon AWS, Google Cloud, Linode, Rackspace, or Microsoft Azure. If you don't have a substantial on-premise data center, you won't achieve the same scale as with one of these hosts.
Ultimately, the choice is yours. But for most companies aiming for significant growth, microservices are the way forward.