Microservices vs Monolithic Architecture

Summary

This video explores the concept of microservices, explaining how they differ from traditional monolithic architectures. Microservices break down a large system into independent, manageable subsystems that can be updated and deployed independently. Each service runs in isolation with its own database, improving scalability and fault tolerance. However, the challenges of slow network communication and maintaining clear service boundaries are also discussed. The video emphasizes the importance of finding the right balance when designing microservices to avoid a distributed ‘ball of mud’, and the need for cohesive groups of functionality.

Takeaways

• 😀 Microservices refer to small, independent services that perform specific tasks within a larger system.
• 😀 A monolith is a traditional architecture where the entire system is built as one unified application, which can grow large and complex over time.
• 😀 Monolithic systems can lead to a ‘Big Ball of Mud,’ characterized by messy, unstructured, and hard-to-maintain code.
• 😀 Modular monoliths improve upon monoliths by dividing the system into smaller, manageable subsystems with clear boundaries.
• 😀 Microservices are individual services hosted independently, which can scale and be updated separately from one another.
• 😀 Each microservice has its own database, allowing for independent scaling and failure isolation.
• 😀 Microservices communicate over a network, using APIs or message queues, which introduces new challenges in managing these interactions.
• 😀 Network calls between microservices are slower compared to inter-process communication within a monolith, and may require more code.
• 😀 The constraints of microservices, like slower communication and breaking API changes, help enforce clear system boundaries and promote loose coupling.
• 😀 Poorly defined service boundaries can lead to a ‘distributed ball of mud,’ where the system is slow, error-prone, and lacks cohesion.
• 😀 Making services too small (known as ‘nanoservices’) can result in tightly coupled services that defeat the purpose of microservices and cause maintenance issues.

Q & A

What does the term 'microservices' refer to?

'Microservices' refers to a software architecture style where an application is broken down into small, independently deployable services. Each service is responsible for a specific functionality and can be updated and deployed independently.

How is a microservice different from a monolithic architecture?

A monolithic architecture is a single, unified application where all components are tightly coupled and share a single codebase. In contrast, microservices are smaller, independent services that interact with each other over a network and can be deployed separately.

What is a 'Modular Monolith'?

A Modular Monolith is an architecture where a large system is divided into smaller, manageable subsystems, each with its own boundaries. These subsystems are still part of the same application but are more loosely coupled and easier to navigate compared to a traditional monolithic architecture.

What benefits do microservices provide compared to a monolithic architecture?

Microservices allow for independent updates and deployments of services, scalability, and fault isolation. They help identify performance bottlenecks more easily and ensure that a failure in one service doesn't bring down the entire system.

Why is it important for each microservice to have its own database?

Having an independent database for each microservice ensures that each service can scale and fail independently without affecting other services. It also reduces the risk of data corruption or unintentional dependencies between services.

How do microservices communicate with each other?

Microservices communicate with each other over a network, using APIs such as HTTP requests or message queues. This allows services to interact while remaining independent from one another.

What challenges do microservices present in terms of API management?

Microservices require careful management of APIs, as changes to one service’s API can break other services that rely on it. Ensuring compatibility and managing versioning is crucial to prevent disruptions.

What is a potential downside of microservices due to their network communication?

One downside of microservices is that network calls are generally slower than inter-process communication, requiring more complex code and potentially introducing latency and errors due to the distributed nature of the system.

What is the 'distributed ball of mud' and how can it be avoided?

The 'distributed ball of mud' refers to a situation where a microservices architecture becomes too complex, with poorly defined boundaries and too much inter-service communication, leading to slow and error-prone interactions. To avoid this, services should be carefully designed with well-defined boundaries and avoid excessive dependencies between them.

What are 'nanoservices' and why might they be problematic?

Nanoservices are extremely small microservices that perform only a single function. While they might seem efficient, they can lead to excessive inter-service dependencies, requiring multiple services to be changed for even simple tasks, which defeats the purpose of having independent services.

How can domain-driven design (DDD) help in designing microservices?

Domain-driven design (DDD) helps by identifying 'Bounded Contexts,' which define the boundaries of each microservice based on the business domain. This ensures that services are cohesive and well-aligned with the organization's needs, leading to better organization and maintainability.