Application’s architecture describes the behavior of applications that focuses on how they interact with each other and with users.
In a web application architecture, there are major independent software architecture components called layers. Here they are:
- Presentation Layer (Presentation Services and Presentation Logic).
- Business Logic (Business or Application and Data Logic).
- Data Layer (Data Services and File Services).
Let’s look at the components of the application’s layers and their functions a bit closer:
- Presentation Services are means of presenting info on the screen.
- The logic of the presentation describes the rules and scenarios of user interaction with an application.
- Business or Application Logic describes rules for making decisions, computational procedures, etc.
- Data logic means operations with data stored.
- Data Services perform internal DB operations – DBMS actions called in response to queries.
- File Services conduct standard actions with files and a file system.
Microservices vs Monolithic Applications
In a monolithic architecture, the app has a single code base with multiple modules that are dependent upon each other and a common database.
A microservice architecture, in its turn, consists of autonomous API – interconnected services. Each microservice is self-contained and implements a specific business capability. Each microservice possesses in itself a presentation layer, business logic layer, and data layer.
Monolith vs Microservices Pros and Cons
Development and Deployment
The monolithic architecture is easier to develop as it doesn’t require a diverse technology stack and is frequently limited to several commonly used frameworks or programming languages. Development is performed with one directory and deployed fast on the server after testing.
With microservice architecture, you’ll need a team familiar with a larger amount of technologies. Microservices require more time to develop, test and deploy. But at the same time, it’s easier to roll back one of them or make changes to the project comparing to a monolith app.
Microservice vs Monolithic Performance
Monolithic apps with a properly built architecture show good performance, especially in the early stages of the project. Over time, as the product develops and enters new markets, the number of users and the load increases. As bottlenecks in performance appear, most of the big and successful applications are transferred to microservices. In microservices, a load balancer distributes the load over the servers. There are also services (e.g. Elastic Beanstalk) that can vary the number of servers to stabilize the work of application for all users.
Accessibility and Reliability
These two things are most important for today’s users. We transfer personal info, fulfill payments, demand high-quality service here, now and at full volume. That’s why we are not ready to tolerate the unavailability of the app, its decline, or running out of work. It happens that a customer cannot correctly assess the estimated load on the application. One lays a certain percentage of the margin, but in reality, the number of requests to the system can grow many times. Sometimes startups may get into such situations, facing explosive growth. Still, even experienced companies that brought the product for a specific short-term goal (e.g. population census) may encounter problems with availability. For such situations, microservices is a good reply. In the case of server overload or crash, an additional one will be connected.
Scalability
Monolithic architecture cannot grow infinitely. Continuous growth can lead to two unfortunate consequences: Firstly, controllability falls, and secondly, performance problems begin.
With Microservices when the need for growth arises, it is not necessary to scale the entire system, disassembling it to the base. It is enough to make the required changes only at a particular microservice.
What Architecture is Better For What Projects
Many successful apps started as a monolith and transferred to microservice with time. It is possible when modules are loosely coupled. When the monolith grows, and complexity cannot be controlled, when making changes is getting harder, then going to microservices is a good idea. Sometimes when the app wasn’t developed following the Dependency Inversion Principle, then it needs to be rewritten for the microservices.
Monolith architecture is ideal if you:
– have a small team
– have an MVP version of a new product
– need a fast time to market
– don’t expect explosive growth
– don’t plan to conquer new markets.
Microservice architecture is beneficial if:
– you don’t have a deadline for launching a product
– scalability and reliability go first for you
– you need to make constant complex changes to the product.
Conclusions
Monolithic architecture is better for MVPs, or simple apps and shows good performance. Microservices are suitable for complex projects with lots of users and give high accessibility, reliability, and scalability. To get more information on the best-suited architecture of your application, request a free consultation from our specialists.