MONOLITHIC ARCHITECTURE VS MICROSERVICES ARCHITECTURE

I am sure you’ve encountered a topic like Monolithic VS Microservices architecture less often than you’ve heard people discuss programming paradigms, tools, or software frameworks. You must select the type of software architecture at the very undertaking of your project. It helps define the design of your application and is one of the primary stages of the discovery stage of the app life cycle. Whether it’s monolithic or microservice after developing the app, changing the software architecture is demanding, time-consuming, and costly.

Software architecture is the structure and organisation of a system. This structure consists of components, their environment, how they interrelate, and the concepts used to design the software. In most cases, it usually involves the evolution of the software into the future. Software architecture is created with discrete missions in mind. Those missions have to be achieved without obstructing the tasks of other tools and devices. The structure and behaviour of the software affect notable decisions, so they must be competently rendered and built for the best possible results.

This article will help you understand these two types of software architecture. We set monolithic and microservices architectures side-by-side, define what they are, and mention the main concepts you should pay attention to. Let’s explore!

Monolithic Architecture

Monolithic Architecture is the traditional model of designing a software program built as a combined unit that is enclosed and independent from other applications. This architecture is considered the traditional approach to building and creating applications as single, unified units. Typically, this approach consists of a client-side user interface, a server-side application and a database. A monolithic architecture is an extensive computing network with one large codebase that integrates all the business concerns.

When you want to change a monolithic application, you’ll have to update the whole stack by accessing the code base and building and installing an updated version of the service-side interface.

Monolithic software is usually made of three components;

• Client-Side User Interface – consists of HTML pages or Javascript running in a browser
• Server-Side Application – handles HTTP requests, implements domain-specific logic, recovers and updates data from the database and fills the HTML views to be sent to the browser.
• Database – contains many tables commonly in a relational database management system.

This model can stream the ETL pipeline as data moves into a single database through the monolith. However, even though you apply a microservices model, you can as well simplify your ETL pipeline with a codeless solution like Xplenty.

Advantages of Monolithic Architecture

An organisation can gain from a monolithic architecture depending on various factors. Utilising a monolithic architecture when building your application has several advantages, and below are some of them.

• Easy handling of issues that may affect the whole software. Usually, developers call the issues cross-cutting concerns, including performance monitoring, caching, logging, and handling. Everything is placed in one position in a monolithic application and not scattered between microservices. The monolithic architecture will extensively minimise the difficulty involved in addressing such concerns.
• Simplicity. When building small to medium-sized applications, monolithic architecture is simpler to develop, deploy and scale. Most Integrated Development Environments and development drives support monolithic architecture as the traditional model of building applications. End-to-end testing is much easier when dealing with only one extensive codebase.
• Performance. Monolithic applications usually have better performance than microservices. One API can serve the same objective in monolithic applications because it has consolidated code and memory.

Disadvantages of Monolithic Architecture

Monolithic applications are convenient until they expand and their scaling becomes an issue. Deploying a slight change in one function needs compiling and testing the whole platform, which is against the modern agile approach that most developers are utilising. Monolithic architecture has some disadvantages, and below are some of them.

• Scalability Potential. The scalability potential of a monolithic application depends on its size. If you wish to design an extensive and complex application, then there are better software architectures than monolithic architecture. In a more complex application, the scalability will be vast. It will become a considerable concern as managing and containing an aggravated software project under one large codebase will be more strenuous.
• Flexibility. Monolithic applications are stiff when it comes to flexibility. With a monolithic application, expect to use it for quite some time without changing your tech stack. And altering your stack is virtually impossible with a monolithic architecture. You’ll have to rewrite your software to house the stack you wish to implement, which requires extensive resources and is not worth it.
• Monolithic architecture makes your code more complicated. Because there is a single codebase, it becomes exponentially complex as the application develops and changes. Those changes or updates call for coordination across the application, yet users can extend them beyond a single portion.

Microservice Architecture

While a monolithic application is a single integrated unit, microservice architecture divides it into several smaller self-contained units. These units usually execute every application process as an independent service. Therefore, all the services have their database and logic and perform specific functions.

Microservice architecture is an approach where a single application is developed as a suite of small services, each operating in its process and communicating with lightweight mechanisms, usually an HTTP resource API. Sam Newman, an independent consultant, says, “Microservices are the small services that work together.”

Microservice architecture is made up of a collection of tiny, autonomous services. Each service is independent and implements one business or technical capability of the application they encapsulate within a bounded context. A bounded context refers to a natural section within the organisation and provides a clear boundary within which the domain model exists.

Microservices architecture remarkably affects the relationship between the database and the application. So, instead of utilising a single database with other microservices, each microservice has its database. A database per microservice is vital if you wish to benefit from this architecture to ensure loose coupling.

Components of Microservice Architecture

Microservices are small, self-contained and loosely coupled. A small team of programmers can write and support the service since each service owns its database. Services are responsible for preserving their data or external state. This contradicts the traditional approach, where a separate data layer handles data preservation. Here are some of the components of a microservices architecture

• Orchestration. This component is concerned with placing services on nodes, recognising failures, stabilising services across nodes, etc. Usually, this component is an off-the-shell tech like Kubernetes instead of custom-built.
• API Gateway. The API gateway is the entrance point for clients. Instead of calling services directly, clients phone the API gate and forward the call to the proper services on the back end.

Advantages of Microservices Architecture

Microservices architecture has advanced thanks to the cloud, containerisation and hyperconnected systems. Also, microservices architecture has some benefits for the user, as listed below.

• Improved Agility. With this kind of software architecture, developers can work on independent modules. Each developer can create and deploy a module independently, minimising the team’s operational friction. Also, it’s easy to control bug fixes and update releases. You can update a service without redeploying the whole application and cancel the update if it goes wrong. Usually, when a bug is discovered in one part of monolithic applications, it can block the entire release process.
• Better scalability. Microservices architecture can scale every single service independently. It enables you to scale out subsystems that need more resources without scaling out the whole application. Scaling monolithic applications consumes time and costs even when it’s not required. Utilising an orchestrator like Service Fabric or Kubernetes packs an increased density of services onto one host, allowing efficient utilisation of resources.
• Microservices architecture encourages decentralisation. A focused central government is critical to successful governance. This kind of structure would be easy to take down, politics aside. Centralisation of things to one place means when one goes wrong. The entire system falls apart. Microservices architecture embraces decentralisation, whereby developers operate more independently and can work as a team regardless of location. Also, there’s flexibility. You can implement several tech stacks in a single application. This helps you select the most influential tech stack to design a service.

Disadvantages of Microservices Architecture

The benefits of microservices are too good to be free. The drawbacks of a microservices architecture are a little hard to bear. Also, you must be sure whether you choose the exemplary software architecture for your business.

• Complexity. Microservices architecture has several moving parts than monolithic architecture. Every service is simple, but the system as a whole becomes complex. Communication between services is complicated; APIs usually encourage this communication and are typically implemented to link software platforms. Complexity in microservices applications increases with the increase of microservices.
• Network Congestion. Using a lot of small services can cause interservice communication. And when the chain of service dependencies becomes very long, the extra latency becomes an issue. This means you’ll need to create APIs carefully. Think about serialisation formats and look for places to use asynchronous communication patterns.
• Development and testing. Designing a small service that depends on other dependent services needs a different approach than writing a traditional layered program. Available tools are not always created to operate with service dependencies. Refactoring across service borders gets strenuous, and testing service dependencies is complex, especially when the application evolves quickly.

Migrating from Monolith to Microservices

Scalability is the main reason developers move from monolithic to microservices architecture. Scalability on rarely used components is insignificant. Components utilised by most users should be considered first when moving. Here is a typical procedure to move from a monolithic system to a microservices approach.

1. Identify the logical components.

There are mainly three information components with the data utilised in the system; data objects, actions, jobs to perform, and use cases. The logical constructs are the data objects that represent the data being used. Data actions are commands to execute a task on single or multiple data objects. The jobs to perform represents the functions users call to perform their roles.

2. Refactor Components

When all components have been identified and assembled, organise them internally—some duplicate functionality must be dealt with before applying the microservice. There should only be one microservice that executes any function.

3. Identify Component Dependencies

After identifying and organising the components for migration, the system must recognise the dependencies within the components. This undertaking usually uses a static source code analysis to look for calls between different libraries and datatypes.

4. Spot Components Groups

The system architect needs to concentrate on categorising the components into groups that can be changed into microservices. The objective is to find a small set of objects and their elemental actions that must be separated in the final system.

5. Create an API for Remote User Interface

The remote User Interface is the only approach to communication between the system, its components and the system’s users. This interface must be systematically planned and scalable to prevent issues as the system grows.

6. Move Component Groups to Macroservices.

Macro services tend to have a moderate posture toward apportioning data repositories and empower more complex interactions with data objects. Therefore, it is vital to consider their use as a provisional step to complete the migration.

7. Move Macroservices to Microservices

Pulling data objects, components and functions from the monolithic architecture to macro services will offer an insight into how these components can be divided further into microservices. Remember that every microservice contains its database and executes only a limited set of actions on its data objects.

8. Deployment and testing

The following step involves integration testing and deployment when the microservice is ready. The monolithic architecture has to be customised to use the new service for its data demands instead of its legacy database.

Conclusion

Embracing a microservices architecture is not an all-purpose approach. Despite being infamous and less famous, monolithic architecture has robust and heavy-duty advantages over microservices, as well as its strengths. You should start with a monolithic architecture to validate your fresh business idea. A small team of developers accompanies you to develop a simple application without needing microservices.

Microservices architecture is more satisfactory for extensive and complex applications. It provides product solutions for a complex system with several functions and services within a single application. Microservices are perfect for platforms covering many user journeys and workflows.