Monolithic architecture and microservices are often seen as opposites. It’s common to see discussions centered around monolithic vs microservices because they polar opposites of each other. Monolithic is seen as the older type while microservices is the new and hot prospect. On a technical standpoint, Monolithic is the solid, all-in-one, and self-contained system while microservices is a fluid, multiple, and compartmentalized solution.
A casual observer might think that the monolithic, as its name implies, belongs to the past and microservices is the new standard. However, there are instances when developing apps and services using a monolithic architecture is more beneficial.
In this article, we’ll discuss the difference between the monolithic and microservices architecture and discuss when is one more applicable than the other.
Ready to learn? Let’s go!
- What is a monolithic architecture
- Advantages of monolithic architecture over microservices
- Disadvantages of monolithic architecture
- What is microservices architecture
- Advantages of microservices architecture over monolithic
- Disadvantages of microservices architecture
- Monolithic vs microservices architecture comparison
- How to choose the right architecture
What Is a Monolithic Architecture?
The term “monolithic” comes from the combination of two words. Mono, meaning one or singular and Lithic, meaning like a pillar or stone. Monolithic application or software is self-contained, meaning everything that it needs to produce a service or result can be found within. Such software is not made for just one task but designed to run several interconnected tasks to achieve a goal or process.
Take for example an eCommerce application that has the product menu, ordering system, database, and payment system all in a single-tiered system. Everything from the customer-facing front end to the back end services is all contained in one application or software.
To put this in perspective:
Imagine a multi-storey grocery building with each floor having a unique purpose. The ground floor could be the lobby (customer facing), the second floor is the grocery racks (product display), the third floor is the cashier (payment system), and the fourth floor is the baggage counter (delivery and fulfillment). The building contains all the subsystems needed to complete a grocery store. The grocery buying process is done and completed inside the building.
Advantages Of Monolithic Architecture Over Microservices
Simple to develop. It is simpler to plan, design and to develop because it is a well-established architecture. Almost any software developer has studied and used it because it is a basic way to build programs.
Readily available components. There are existing templates, frameworks, scripts which can be applied to develop a program. Most of the existing software tools, hardware, servers, and interfaces work in a monolithic architecture vs microservices.
Simple to launch. Deployment to production is easy since you only need to copy the software or application package to a server. It’s literally as easy as copy and paste.
Simple to test. Testing and debugging is easier, cheaper, and faster. In part due to the ease of deployment since all features are available upon launch, everything can be tested in the quality assurance phase.
Disadvantages Of Monolithic Architecture
Limited in size and scale. Adding a new feature or software module can be difficult due to the singular nature of the system. A single change, no matter how simple, can affect the entire architecture. Moreover, although it’s easy to test a monolithic system during the launch phase, it’s may be very hard to test the effect of a change and will require extensive quality assurance checking.
Harder to implement innovation. It is almost impossible to adopt new technologies since this will require a core framework change (e.g. A change in software language). Such exercise is costly and would require a long process, one can argue that’s it’s almost like building a new one from scratch.
Steep learning curve. This refers to anyone studying or analyzing the application. It is often too large or complex to understand for a developer that’s being onboarded after the development or launch stage. Applications are indeed more simple to develop using monolithic vs microservices architecture but once running, these programs can be hard to analyze when passed to a new development team.
Slow startup and update. The size of the application will lead to sluggish startup or slow booting time. Also, any update to any of the applications will require you to redeploy the entire application. Which, as mentioned earlier is not that difficult since it’s a copy-paste exercise only. But, this will mean shutting down the application to accommodate the redeployment.
Reliability issue. A software or application should run error free if expertly developed. For monolithic systems, this is especially crucial since a single bug or error will affect the entire system. This is due to the use of a single code to create all the applications, meaning all will have the same vulnerability and weaknesses.
What Is Microservices Architecture?
Microservices architecture is a way to develop a service by creating a collection of services, each having its own function. These multiple services are independent of each other but will be “bridged” together by a communication solution (e.g. application programming interface or API).
Each service on its own won’t accomplish the end goal of the system and would need to be interconnected with all the services to be a complete solution.
Going back to the eCommerce example, developers can work on separate parts of the eCommerce platform exclusively without the burden of thinking about the other services since their actions will not have an effect on the other services. A team of developers can split into four and each will work on the User interface, Product display, Payment, and Fulfillment. Once done, the four parts will be interconnected to create an eCommerce platform.
Taking the grocery building metaphor:
Instead of creating a building with all the departments inside the microservices approach will be to build 4 smaller separate buildings close to each other. Each building will house one department and the grocery buying process goes through all 4 buildings to complete the service.
Advantages Of Microservices Architecture Over Monolithic
Scalability. A developer can upgrade or change a service without affecting the entire system. The ease of scaling is aided by the architecture’s software language flexibility. Any service can be written in different programming languages and still interact well with other services as a cohesive whole thanks to APIs.
Better performance. All things being equal, when comparing microservice vs monolithic applications, microservices should perform better than monolithic ones. Developers can respond to errors faster and by isolating the problematic subsystem, the error can be fixed while the entire system is still active. It is also possible to see which service is being taxed or running at full capacity. You can then upgrade or improve this service independently to remove system bottlenecks.
Fewer mistakes. This will still, of course, depend on the developer’s expertise but due to the parallel development of each service there is little or no chance that the entire system will be brought down by bug affecting one service. The independent services also have their own database and are not reliant on a central database. Each sub-service can even differ in database types, with each using the one best suited to its function.
Application independence. Each service or component is connected but not dependent or affected by other services. This is very useful when troubleshooting or improving one facet of the software. As a developer, you can be more creative with your solutions without fear of bringing the entire system down.
Faster deployment. A team of developers can produce a solution faster because they can independently deliver each application in parallel. Each team may not even need to collaborate with each other until it is time to integrate the system for deployment.
Disadvantages of Microservices Architecture
Complex development. The integration of the multiple services requires knowledge of inter-process communication, usually APIs, to orchestrate everything. A badly configured or developed service can have difficulty establishing communication with the rest of the system, resulting in a longer overall time frame.
Although it is easier to upgrade or debug a microservice system due to it’s decoupled architecture, this same reason, in turn, makes it difficult for a developer to initiate a system-wide that touches on several services. You need to plan for each service taking into consideration each one’s unique parameters.
Managing multiple databases is challenging. With each service having its own database, the software owner would need to monitor and maintain multiple databases. For applications needing to access and update databases across the entire system, this distributed way of database access can slow down the system’s process.
Complex testing. The number of services affects the complexity of testing activities so much so that manual tests are not doable. You would need to develop special automated tests and create multiple test environments covering every conceivable scenario. After development, running the test might yield even more anomalies that need testing.
Initial development is more expensive. The increase in cost comes on two fronts, the initial development cost, and the operational cost. The multi-tiered application would require more developmental time, effort and expertise.
Each service would need to have its own server or instance. With the advent of virtual machines and cloud service container, the capital expense for the servers is somewhat lessened. But the number of virtual machines or servers will demand an increase in operational cost.
Complex deployment. Unlike the simple copy-paste like deployment of monolithic applications, microservices have multiple service packages that need to be deployed. Each one needs to be configured and deployed with each service having its own script, executable files, database, and unique system. Thus the more subsystems, the more complex the deployment.
Monolithic vs Microservices Architecture Comparison
|Monolithic architecture||Microservices architecture|
|Simple to develop and deploy||Complex and hard to develop and deploy|
|Code changes affect the entire system||Only the microservice that is changed would be affected|
|Inter-service communication||Using APIs for communication|
The entire system will be tested at once.
|Testing is much more complex
Done on a per unit or component level after which a system-wide test can then be done
|One codebase and one shared database||A codebase and database for each microservice|
|Hard to scale or upgrade||Very scalable and upgrade|
|Less expensive and faster to develop||More expensive and takes more time to develop|
|The entire system can be affected by a single error or bug||The entire system is shielded from the error or bug on one sub service.|
How to Choose the Right Architecture?
It goes without saying that microservices are way more modern than monolithic architecture. The readiness of microservices to implement innovation and readily adapt to new technology makes this architecture type the best fit for almost any enterprise. However, there are still cases where a developer should consider sticking to the same old monolithic architecture.
You should choose monolithic architecture if:
- You have a startup at its founding stage
- You don’t have access to a highly-skilled team of developers
- In the span of a few years, you don’t foresee the need to support high traffic capacity (for instance, it’s an app with a limited location span)
- Your infrastructure can’t handle running more than one database server
You should go with microservices if:
- You consider developing in different languages (one microservice needs to be written in an efficient language like C++ while others can be coded in Ruby on Rails)
- You have enough budget to ensure rapid growth and fast scaling
- You plan to expand your development team
- The agility and adaptability of your service is highly important
Well, both architectures have their pros and cons, hopefully, this article will help you understand which project or product requires a monolithic or microservices approach. To recap, monolithic is more applicable to simple and lightweight applications like simple eCommerce and blog platforms.
While microservices are for bigger and complex applications that would need to scale quickly. Popular example of companies that built their applications using microservices are Netflix, Amazon, and eBay.
If you need help in determining which architecture is best for your application, contact us and our expert developers can provide you with guidance to help you make an informed decision!