With the rapid advancement of new technologies, organizations of all sizes are increasingly focusing on digital transformation, which involves the adoption of new innovative tools. It is essential for companies to proactively consider how they can leverage emerging technologies and adapt their applications accordingly to remain competitive in the market.
When it comes to designing your application's architecture, the choice between monolithic and microservices approaches is crucial. Understanding the distinctions and trade-offs between the two will help you make an informed decision that aligns with your project's requirements.
Over the years, there have been substantial changes in the development and deployment of applications, from the 1980s to the present. The evolution of how organizations have developed, deployed, and managed applications can be seen through three distinct phases:
- 80’s – mid 90’s: Data Centers with physical servers, running monolithic applications, developed using traditional waterfall methodologies.
- Late 90s–00s: Datacenters and hosting providers running Unix/Linux servers, the emergence of virtualization (VMWare, KVM), running n-tier applications, developed using agile methodologies.
- ~ 2010 – Now: Cloud increasingly replacing data centers and hosting, decomposition of applications into microservices, running on a container infrastructure, managed and orchestrated by Kubernetes, developers, and operations collaborating using DevOps methodologies.
The exact architectural style you adopt for your application will depend on your unique needs, but monoliths and microservices are predominant architecturals. To determine which is right for you, you should first understand the differences between monolithic and microservice applications, as well as their advantages and disadvantages.
What is Monolithic Architecture?
Under the monolithic architecture paradigm, all discrete elements of an application, encompassing business logic and user interface, are contained within a unified codebase. This model relies on a singular programming language, repository, and environment, resulting in comprehensive implications from any modifications introduced.. A monolithic architecture makes use of tight coupling, so components are highly dependent and interconnected.
This means that different components of the application, such as the user interface, server-side logic, database operations, and application integration, are all part of a single software unit. To change one component, you must alter that singular code base and update the entire system.
For a while now, monolithic architecture has been the preferred choice for many developers, especially those working in smaller organizations or with limited team sizes. Monoliths are particularly well-suited for applications that do not need constant updates.
Pros of monolithic architectures
While monoliths may sometimes be overlooked because of their legacy status, they have a number of benefits.
- Simple development. A monolith is the standard for a reason — all of the code lives in one place, so it’s easier to build upon. New team members will be able to pick things up faster.
- Simple debugging. Because all of your code is in one place and your service has no dependencies, it’s easier to identify the source of an issue. Developers will have an easier time recreating environments for testing.
- Standardization and velocity. Standardization has become increasingly important. Monolithic architectures establish that standard through a singular codebase, keeping data centralized.
Cons of monolithic architecture
Monoliths may have an edge when it comes to simplicity, but that doesn’t make them the ideal architecture for every application. There are a few downsides to monoliths:
- Scalability. With a monolithic approach, you can’t scale individual components. Even if you’re adjusting a single component, you have to retest and deploy the whole application.
- Slow development. With an entire team working from the same codebase, developers have to tread carefully, which can slow them down. Testing becomes even more important — and more painstaking — since a single issue can impact the entire application.
- Tech stack lock-in. By using a single programming language and a single repository, your developers are locked into a single way of doing things. With monoliths, you don’t have the flexibility to adopt new technologies as they emerge.
What are Microservices?
Microservices structure an application as a collection of small, loosely coupled, and independently deployable services. Each service focuses on a specific business capability and can be developed, deployed, and scaled independently of other services. These services interact through well-defined APIs, typically using lightweight protocols like HTTP or messaging systems.
One of the core tenets of microservices architecture is the focus on individual services’ autonomy. By adopting this approach, organizations can also foster greater team autonomy, allowing development teams to take ownership of specific microservices and make decisions independently. This empowers teams to choose their preferred technologies, programming languages, and development methodologies, fostering a culture of innovation and accelerating time-to-market.
Key Principles of Microservices Architecture
- Single Responsibility: Each microservice is responsible for a specific business function or capability. This principle ensures that services remain focused, maintainable, and easily replaceable.
- Decentralized Governance: Microservices empower development teams to make decisions independently, promoting agility and autonomy. Teams can choose different technologies, programming languages, and frameworks that best suit their service’s requirements.
- Independent Deployment: Microservices can be deployed independently, enabling faster release cycles, reducing the risk of failures, and allowing for seamless scalability.
- Fault Isolation: Since microservices are decoupled from one another, failures or issues in one service do not necessarily affect others, enhancing the overall system’s resilience and fault tolerance.
Pros of microservices architectures
Microservices architecture has gained significant popularity in the development of cloud-native applications. This architectural style offers numerous benefits that align well with the principles of cloud computing and enable organizations to build scalable, resilient, and agile systems. For instance:
- Scalability
Microservices architecture enables applications to scale horizontally by distributing the workload across multiple independent services. Each one can be deployed and scaled independently based on specific requirements. This flexibility allows organizations to handle varying demand levels and ensure optimal resource utilization.
- Agility and Speed
Microservices promote agile software development by breaking monolithic applications into smaller, loosely coupled services. Development teams can work on these services independently, using different programming languages, frameworks, and deployment technologies. This decoupling of services allows organizations to adopt new technologies and update specific components without affecting the entire application, enabling faster development and deployment cycles.
- Fault Isolation and Resilience
In a microservices architecture, each service operates independently and can handle failures without impacting the entire system. If a particular microservice fails or experiences issues, the other services can function without interruption. This fault isolation enhances the overall resilience of the application, as failures are contained within individual services and do not cascade throughout the system.
- Continuous Delivery and Deployment
Microservices architecture aligns well with continuous delivery and deployment principles. Since each service is developed and deployed independently, organizations can easily implement CI/CD (Continuous Integration/Continuous Deployment) pipelines for individual services, promoting faster and more frequent releases, reduced deployment risks, and the ability to roll back or update specific services without affecting the entire application.
- Team Autonomy and Scalable Development
Microservices enable organizations to adopt a decentralized approach to development. Different teams can be responsible for developing and maintaining specific microservices, allowing for greater autonomy and specialization. This scalability promotes faster innovation, as teams can work independently and introduce new features or improvements to their respective services without coordination with other teams.
- Flexibility and Technology Heterogeneity
Microservices architecture provides flexibility in choosing the most suitable technology stack for each service. Since services are decoupled, they can be developed using different programming languages, frameworks, and data storage technologies. This flexibility allows organizations to leverage the strengths of different technologies and select the most appropriate tools for specific service requirements.
- Improved Fault Tolerance and Recovery
Microservices architecture enables organizations to design applications with built-in fault tolerance mechanisms. Organizations can use service replication, load balancing, and automatic scaling techniques to ensure that their applications can handle failures and recover quickly. Additionally, monitoring and managing individual services are simplified, making detecting and resolving issues easier.
Cons of microservices architecture
Since everything is now an independent service, we’ve to carefully handle requests traveling between modules. In one such scenario, developers are also forced to write extra code to avoid disruption, the complexity of this approach requires greater coordination across your team and comes with a few disadvantages.
- Managing distributed services. As your application grows, you’ll develop dozens, if not hundreds, of services. Managing this many services and their dependencies can be overwhelming without the right tools such Jenkins platform. You need dedicated devops teams that can handle all aspects of a service, from programming to deployment.
- Communication between services. May be complex and there’s a higher chance of failure during communication between different services without the right tools such as service mesh.
- While unit testing may be easier with microservices but integration testing isn’t. The components are distributed and developers can’t test a complete system from their individual machines.
Related Reference:-
https://k21academy.com/docker-kubernetes/monolithic-vs-microservices/
https://www.cortex.io/post/monoliths-vs-microservices-whats-the-difference
https://hatchworks.com/blog/software-development/monolithic-vs-microservices
