The debate on Microservices vs Monolithic architecture represents a significant shift in IT’s approach towards software development. This article will explore both these concepts and their challenges.
In this context, Monolithic refers to everything being composed in one piece. By design, Monolithic software is meant to be self-contained. Contrary to modular software programs that are loosely coupled, monolithic program components are interdependent and interconnected. When you consider a tightly-coupled architecture, each and every component and its related components are necessary to compile or execute the code.
Usually if you want to update any of the program components, the entire applications needs to be rewritten. However with modular application such, any of the separate modules like microservices can be changed with no effect on the other program parts. Modular architecture minimizes the probability that a change in one element will result in unplanned changes in other elements as modules are comparatively independent. As opposed to monolithic programs, modular programs give themselves more readily to iterative processes.
Challenges of Monolithic Architecture
Business use cases are highly agile and their processes evolve constantly. For example, as you can see new regulations are a usual occurrence in banking applications. With Monolithic applications, you can accommodate these kind of changes. However, the downside is that it will reduce agility as even for a small change in the application, you need to repackage and assemble the entire application. This consumes a lot of time and also causes a slowdown in the pace of the delivery of the new application features.
Let’s take the example of a shopping cart application to understand this. When the app continues to get a lot of customer traction, there comes a time when it cannot accommodate new customers anymore. This means that the app need to be scaled both horizontally and vertically.
There are also other parameters on which monolithic application fails ilike Resiliency, Fault Tolerance, and Availability
- The approach is limited in terms of complexity and size
- As the application is complex and large, it is difficult to understand it fully and make correct and quick changes
- The application size can significantly slow down the time taken to start-up
- The entire application needs to be deployed again with each update
- It is difficult to continuously deploy
- Reliability is also a major concern with monolithic applications. The entire process can be disrupted with a single bug. Additionally, the bug can also affect the availability of the whole application as all the application instances are identical
- When there is conflicting resource needs within various modules, it is hard for monolithic applications to scale
- As the effect of change is not understood properly, the manual testing can be extensive
- Monolithic applications also face the challenge of adopting new technologies.
Microservices refers to a software development technique that is capable of structuring an application as a group of loosely coupled services. The distinguishing features of microservices architecture are lightweight protocols and fine-grained services. One of the advantages of decomposing an app into various small services is that it significantly enhances modularity
Also referred to as microservice architecture, microservices is an architectural style that is capable of structuring an application as a group of services that are
- Coupled very loosely
- Has high maintainability
- Owned by a small team
- Can be deployed independently
- Structured around business capabilities
With microservice architecture, it is possible to deliver large and complex applications quickly, frequently and reliably. It also assists organizations organizations to gradually develop its technology stack. You can get familiar with this architecture by undergoing Microservices training that are readily available today.
Uber started out with a monolithic architecture that was developed for a single product offering in one single city. The company found the process of having one codebase clean and easy to solve their core problems. As they started expanding, they faced the challenges pertaining to continuous integration and scalability.
Monolithic Architecture of Uber – Microservice Architecture
In order to avoid the problem, the company decided to change its architecture. For that, they looked towards big companies such as Netflix, Amazon, Twitter and the like. This way, Uber formed its microservice architecture by breaking its monolithic architectures to various codebases.
Refer to the diagram below to look at Uber microservice architecture: