What Are Microservices Really All About? (And When Not To Use It)

Summary

The video script delves into microservices architecture, highlighting its benefits for large teams in building scalable applications with loosely coupled services. It explains the independent deployment, scalability, and communication methods of microservices, such as RPC and event streaming. The script also addresses challenges like maintaining data integrity and the necessity of components like API gateways and service registries. It concludes by discussing the suitability of microservices for large teams and the importance of well-defined interfaces for potential future adoption by startups.

Takeaways

• 🔌 Microservices architecture allows for the development of scalable applications through many loosely coupled services.
• 🛠 Each microservice in the architecture has a dedicated function, such as shopping cart, billing, or user profile management, and is considered a separate domain.
• 🔗 Microservices communicate through well-defined interfaces with small surface areas to limit the impact of failures and defects.
• 🚀 They can use remote procedure calls (RPC), event streaming, or message brokers for communication, each with its advantages and drawbacks.
• 🚦 Microservices can be independently deployed, providing operators with confidence and flexibility in frequent deployments.
• ⚖️ The architecture offers operational flexibility to scale individual services independently, which is highly valuable.
• 🔒 Well-architected microservices practice strong information hiding, often involving breaking up monolithic databases into logical components.
• 🗃️ One challenge with microservices is maintaining data integrity without the traditional database foreign key relationships and referential integrity.
• 🚪 A key component of microservices architecture is the API gateway, which routes incoming requests to the appropriate microservices after authentication.
• 📍 The API gateway uses a service registry and discovery service to locate and route to microservices, which must register and discover each other's locations.
• 🛑 Additional components like monitoring, alerting, and DevOps tools are essential for the successful implementation of microservices architecture.
• 💡 Microservices architecture is most beneficial for large teams, enabling team independence and fast movement with contained failure impacts, but may not be suitable for small startups due to the overhead involved.

Q & A

What is the main advantage of using microservices architecture for large teams?

Microservices architecture allows large teams to build scalable applications by decomposing them into many loosely coupled services, which enhances team independence and allows each team to work on their respective domains with agility and reduced risk of widespread failures.

How are microservices defined in the context of an application?

Microservices are individual components of an application that handle dedicated functions, such as shopping cart, billing, user profile, and push notifications. They operate independently and communicate with each other through well-defined interfaces.

What is the significance of having small surface areas in the interfaces of microservices?

Small surface areas in microservices interfaces limit the impact of failures and defects, making it easier to understand and manage the interactions between services within the larger application context.

How do microservices communicate with each other?

Microservices communicate through a combination of remote procedure calls (RPC), event streaming, or message brokers, each offering different trade-offs in terms of response time and isolation.

What is the impact of using RPC for communication between microservices?

RPC, such as gRPC, provides faster response times but has a larger blast radius, meaning if a service goes down, it can have a more significant impact on other services.

Why is it beneficial for microservices to be independently deployable?

Independent deployment of microservices allows for more frequent and confident releases, as each service is smaller and has a limited impact area, reducing the risk associated with deployment.

What operational flexibility does microservices architecture provide?

Microservices architecture offers the flexibility to scale individual services independently based on demand, which is invaluable for optimizing resource usage and application performance.

Why is strong information hiding important in well-architected microservices?

Strong information hiding in microservices helps to encapsulate the logical components within each service, promoting better modularity and reducing dependencies between services.

What are the implications of breaking up a monolithic database into logical components for microservices?

Breaking up a monolithic database into logical components for microservices means that foreign key relationships and referential integrity can no longer be enforced at the database level, shifting the responsibility of maintaining data integrity to the application layer.

What role does an API gateway play in a microservices architecture?

An API gateway in a microservices architecture handles incoming requests, routes them to the appropriate microservices, and relies on an identity provider for authentication and authorization of requests.

Why is a service registry and discovery service important for microservices?

A service registry and discovery service is crucial for microservices to locate and communicate with each other, allowing the API gateway to route requests and services to discover each other's locations.

When is microservices architecture most suitable for implementation?

Microservices architecture is most suitable for large teams with the resources to manage its complexity. It enables team independence and rapid development but may not be ideal for small startups due to the overhead involved.

What advice is given to startups considering the adoption of microservices architecture?

Startups are advised to design each function in the application with a well-defined interface, making it easier to migrate to a microservices architecture if the business and team grow and it becomes more appropriate.