Monolith and Microservices Architecture
Modern applications must scale quickly, deploy frequently, and remain resilient under heavy demand. This is why the debate between Microservices Architecture and Monolithic Architecture has become one of the most important architectural decisions in modern software development.
What is Monolith Architecture?
Monolithic architecture is a traditional software development model where an entire application is built as a single unified unit. All the code exists in single Repo.
Scaling a monolith architecture usually means replicating the whole application on the multiple servers rather than scaling a individual components.
Advantages of Monolith Architecture
Easy deployment – One executable file or directory makes deployment easier.
Development – When an application is built with one code base, it is easier to develop.
Easy debugging – With all code located in one place, it’s easier to follow a request and find an issue.
Cost Effective
Disadvantages of Monolith Architecture
Scalability – You can’t scale individual components. Let suppose in above example if the tweet service is getting more traffic then the system cannot scale that service. Instead entire application is scaled which means Authentication and Chat service are also replicated even when they do not require additional resources.
Reliability – If there’s an error in any service, it could affect the entire application availability.
Deployment – A small change to a monolithic application requires the redeployment of the entire monolith.
What is Microservice Architecture?
Microservice is a software architecture where application are build as a collection of small, independent service. These services have their own business logic and database with a specific goal. Updating, testing, deployment, and scaling occur within each service.
How it works?
The client sends a request.
The API Gateway routes the request to the correct service.
Each service processes the request and returns the response.
API Gateway
API Gateway is a single entry point for all client requests in a microservices architecture. Instead of clients communicating directly with multiple microservices, they send requests to the API Gateway, which forwards the request to the appropriate service.
Without an API Gateway, the client would need to remember the address of every microservice (such as User Service, Order Service, Payment Service), making the system complex and harder to manage.
The API Gateway simplifies communication by handling request routing. For example:
/auth→ routed to Auth Service/tweets→ routed to Tweet Service
It can also handles:
Authentication and Authorization
Rate Limiting
Characteristics
Independent Service
Each service is developed and deployed independently.Independent Scaling
If a particular service is receiving more traffic, then we can scale that service.
For example: Iftweet serviceis receiving more traffic then only tweet service need to scale.Tweet Service → 4 instances Auth Service → 2 instances Chat Service → 1 instance
Advantages of Microservices
Independently deployable – Since microservices are individual units they allow for fast and easy independent deployment of individual features.
High reliability – You can deploy changes for a specific service, without the threat of bringing down the entire application.
Technology flexibility – Microservice architectures allow teams the freedom to select the tools they desire.
Better fault isolation – Failure in one service usually does not crash the whole application.
Disadvantages of Microservices
Higher system complexity – Managing many small services is more complex than a single application.
Network latency – Communication between services over the network can slow down requests.
Higher system complexity – Managing many small services is more complex than a single application.
Data consistency challenges – Maintaining consistent data across multiple services can be difficult.
