Monolithic Application vs Microservices Architecture: What They Are and Which May Suit You

In the modern age, enterprises increasingly depend on software-based systems for their business-critical activities and processes. The design and construction of those systems, therefore, can have a profound impact on productivity and efficiency within your company. That’s what makes it crucial to understand the difference between a monolithic application and microservices architecture; two of the principal software development approaches. That’s what this guide is here to help with. 

What is a monolithic application?

A monolithic application—sometimes also known as a monolith application or monolith software—is a specific software program form, whereby the application is constructed in a single block. All components are tightly coupled into that one cohesive unit. 

A monolithic computing network will use one code base and runtime environment to create a single-tiered application. This means that multiple services, such as APIs, databases, load balancers, and more, will function as one large application organized into different layers. However, all the components, as well as any associated components, need to be present for the software to successfully run.

Monolithic architecture is generally considered a good choice for smaller programs that need quick and cheap deployment, however, they lack flexibility and can be difficult to scale. We’ll go into more detail regarding monolithic architecture pros and cons later on.

Monolithic architecture examples

A typical monolithic application example involves a front-end user interface, a server-side interface, and a codebase (software-supporting database). If your needs are simple and you need a quick turnaround, monolithic is the obvious choice. 

Say, for example, that your business is a startup with plenty of great ideas but not a lot of resources. To launch, start scaling, and attract the attention of investors, you need to get your product to market as quickly as possible.

In this case, monolithic architecture is your friend. You can put an app together rapidly, without expending too many resources. The monolithic architecture allows you to get your business up and running quickly, and you can take the time to optimize and improve your programs later on as you scale.

Monolithic architecture is also a good choice if you know your product won’t need a lot of future scaling. In this case, you can keep things simple and cost-effective without sacrificing quality.

Advantages of monolithic applications

There are still plenty of examples of monolithic applications working well for businesses. Let’s look at some of the principal benefits of a monolithic app: 

Simple development

Monolithic architecture is advantageous if you want to develop an entire application and get it to market quickly. A small team can rapidly pull together and build an executable app using a monolithic system. This makes monolithic architecture ideal for startups without big software development budgets.

Easy deployment

Another of the potential advantages of monolithic applications over microservices and other approaches is that it’s not as complex. It has fewer moving parts, so there are fewer components to manage and fix. The self-contained nature of a monolithic app makes it easier to deploy, manage, and maintain.

Uncomplicated testing and debugging

Because the application is fitted as a single unit and works together as a whole, you can perform monolithic architecture testing and debugging quickly and easily from a central logging system.

Disadvantages of monolithic applications

While those advantages of monolithic application architecture may make it suitable in some circumstances, it’s essential to also consider the drawbacks. If the following disadvantages of monolithic architecture may pose an issue for your business, then monolithic programs are not right for you.

Less scalability

Because monolithic architecture software is tightly coupled, it can be hard to scale. If you want to add new features or your codebase grows, you will need to take the entirety of the architecture with you.

Even if you only want to boost or alter a single function, the entire application needs changing. As well as being time and resource-consuming, this can also cause disruptions to continuous delivery as you try to work out how to scale the monolithic application effectively.

Inability to adapt to new technologies

Once again, the tightly coupled nature of monolith applications can cause issues when it comes to introducing new technology and innovating applications. 

Take a music app, for example. If it’s a monolith application, the catalog is connected tightly to the purchase and play services. While useful in some cases, it means it’s hard to bring in new technologies or web services without dismantling the entire app.

High dependence between functionalities

Monolithic applications can also run into software engineering and downtime difficulties because of their tight dependency. 

Let’s go back to that music app example. Because the catalog, play, and purchase functions are so dependent upon one another, if one goes down, the others will go down with it.

Some people may only want to listen to tracks they already have in their catalog, meaning they aren’t using the purchasing function. However, if that function breaks, the whole app would be functionally unusable until the payment issue was fixed—affecting even those people who don’t need the function.

What is microservices architecture?

Microservices architecture is an alternative approach to the development of applications. Also known simply as microservices, this approach creates a larger application out of multiple, modular services that communicate via APIs. These loosely coupled, independently deployable services use independent databases and coding, as well as a specific business goal.

An individual team is typically responsible for each service used in a Microservices architecture. This allows for updating, testing, deployment, and scaling that is individual to each service and creates manageable complexity.

Microservices examples

Microservices have a lot of applications, but a common one is the restructuring of legacy systems.

Let’s say you’re a well-established company with an unwieldy legacy system. You want to modernize, move your systems to the cloud, change certain functionalities, or improve your digital systems in a more general way.

In this case, microservices can help you to optimize and improve incrementally, without too much downtime or resource expenditure at once.

Microservices are also useful if you need to do a significant amount of real-time data streaming and processing, such as in the case of type streaming services, online banking, or eCommerce applications. Microservices are far more capable of handling this kind of data load than monolithic applications.

Advantages of microservices over monolithic applications

Microservices have a lot going for them. Here are a few reasons why many companies have chosen them to boost their business capabilities:

Independent services

In microservices architecture, each service is developed independently of the others, with the business logic spread over various platforms. This means workflows for one service don’t affect the development of others. Furthermore, resources such as development tools aren’t dependent on irrelevant functionalities.

Instead, each service gets the full attention of its own team. This enables quick and efficient independent development, followed by simply coupling the services together.

Enables agile development

As each service is developed independently, you can choose the tech stack and programming language that best suits each function. This means the best tools can be used for each particular service. In contrast, monolithic web application architecture sometimes forces services into a one-size-fits-all approach.

This kind of agility allows applications to be developed more quickly and efficiently.

Scalable and reliable

We’ve spoken about how monolithic technology can be hard to update and scale. That’s not the case with microservices. Because of each function’s loose coupling, it’s easy to optimize, test, debug, and fix functions independently of one another.

Rather than putting the whole app into downtime and scaling each service, you can instead tweak and upgrade independent services as and when needed. This loose coupling makes microservice architecture services more reliable. One crashed service doesn’t bring down the entire app. If something goes wrong with an API gateway, the other services can still operate independently.

So, to return again to our music app example from earlier, even if the purchase and download functions crashed, customers would still be able to access the user interface and play music they already owned.

Disadvantages of microservices

As in the case of monolithic architecture, you must carefully consider the potential disadvantages of microservices as well. Here are the most noteworthy to be aware of before deciding on migrating a monolithic application to microservices:

Time and resource-consuming

While the individual autonomy of each microservice can speed up development, it can also slow it down. It all depends on how complex of an app you want to make.

While developing an individual microservice is usually quicker and more efficient than developing the same service in a monolithic context, implementing lots of different microservices and putting them all together can take a substantial amount of time.

Furthermore, while microservices allow you to use the optimal tools for each service, putting individualized tech stacks together can require a lot of resources and expertise.

Complicated deployment

Once you’ve developed each microservice, they need to be integrated into a functional app before they can be deployed. This can be a complicated process.

For a start, cross-cutting (in which each microservice needs validation or authorization to proceed) can be difficult. With monolithic architecture, tight coupling means an authorization for one service usually works as authorization across the board. That’s not the case for microservices, and to make it so, you need to perform complicated linkage work.

All in all, deploying microservice architecture isn’t always easy, and it gets harder the more complex your app is.

Complex testing

With microservices, all application parts need to be tested separately, from the software architecture to things like caching, dependencies, and data access. You also have to test that all the services work together properly. This can make microservices testing expensive and time-consuming before the debugging itself has even begun.

It’s obviously important to test before releasing any product to market (and then to run regular functionality tests for as long as the product remains in circulation). If you want these tests to be as quick as possible, microservices may not be for you.

Microservices vs monolithic applications: At-a-glance

When it comes to microservices vs monolith software, some people might be tempted to assume that whatever is newer is better. However, it’s not quite that simple. 

Identifying your business needs and goals is always the key to unlocking your organization’s potential. While microservices allow greater scalability and flexibility, they also require more resources for service coordination and deployment management.

The pros and cons we’ve already discussed should have helped you get an idea of the difference between microservices and monolithic applications. To make things even easier, here’s a brief at-a-glance comparison table:

Converting monolithic applications to microservices: Key considerations

As monolithic architecture is the older program model, many businesses started their software development journeys with this architecture, and have stuck with it. However, businesses that have grown and evolved may now be constrained by their monolithic services. 

So, do you need to start thinking about how to convert a monolithic application to microservices? These are the factors you should consider before making the jump: 

Business goals

Before choosing a software program architecture, you need to assess your business goals. While monolithic architecture has its advantages, it can become complex and difficult to manage as businesses grow. Microservices provide agility and scalability, as well as the ability to independently develop and deploy services and easily add new features. 

If your business is aiming for significant growth, the benefits of microservices, such as faster development cycles, better fault isolation, and improved scalability, will outweigh the costs and complexities of migrating from a monolithic architecture.

Application complexity

Evaluate the complexity of your current monolithic application. If it’s small, well-structured, and adequately meets your current and future requirements, a migration to microservices may be unwarranted. 

There’s no need to upgrade if it doesn’t suit your needs. However, if you want to enjoy some of the benefits of microservices, a hybrid migration could help your business grow without completely abandoning the benefits you’re still gaining from your monolithic architecture.

Resources

Moving from a monolithic architecture to microservices involves significant changes to software infrastructure. They can include breaking down an application into independent services, defining service boundaries, implementing communication mechanisms, and updating deployment and monitoring processes. 

You need to ensure you have the necessary technical expertise, as well as the time and budget to successfully carry out your migration strategy.

Costs

Migrating from a monolithic architecture to microservices can be complex and time-consuming. It’s also not without risk. 

Migration may involve rewriting or refactoring parts of the codebase, updating infrastructure and deployment processes, and ensuring proper integration and coordination among services. Make sure that the long-term benefits of microservices will outweigh the disruptions to your business that the migration process may cause.

Modernize your monolithic application with OpenLegacy

OpenLegacy can bring your monolithic applications into the future without the need for expensive overhauling or expensive middleware. 

With OpenLegacy’s hybrid, cloud-native architecture, you can generate new digital services from the legacy systems, expand your cloud strategy, modernize your legacy architecture, and more. Meaning you maintain all the benefits of your monolith architecture while incorporating the advantages of microservices as well!

Find out how OpenLegacy can support your business’s digital transformation journey and help you adapt to meet the demands of the future today.

FAQs about monolithic applications and microservices architecture

Is it possible to use a hybrid of monolithic and microservices?

The short answer is yes, a hybrid approach, which combines the benefits of both monolithic and microservices architectures, is possible. 

In a hybrid architecture, certain parts of the application are designed and implemented as microservices, but the core functionality remains within a monolithic structure. This allows businesses to enjoy the benefits of both monolithic and microservices architectures.

How can we modernize monolithic applications?

While monolithic architectures have their place, they’re increasingly being superseded by microservices. Many businesses want to gain the flexibility of microservices but feel unable to modernize due to relying on their current monolith applications. 

OpenLegacy’s hybrid approach combines the flexibility of microservices with your legacy monolith systems. There’s no need to switch off your system and commit to a complete overhaul, or patch in a lot of bulky middleware.

We create single functions as microservices, APIs, or other endpoints, which can be automatically connected to elements within your legacy system. These split up system processes and functions, enabling greater modularity and flexibility.

Are communications between microservices secure?

The security of communications between microservices depends on the implementation and configuration of the communication mechanisms. While the communications between microservices are not inherently secure, measures can be implemented to protect data and guarantee security. 

Some key considerations for ensuring secure communications between microservices include authentication and authorization, encryption, secure communication protocols, network segmentation, firewalls, and continual monitoring and auditing.

When choosing a migration service provider, consider the features that they offer to keep your microservice connections secure.