Why microservices exist - Quick Recap

Recall & Review

beginner

What is the main reason microservices architecture was introduced?

Microservices were introduced to break down large, complex applications into smaller, independent services that can be developed, deployed, and scaled separately.

beginner

How do microservices improve scalability compared to monolithic systems?

Microservices allow scaling only the parts of the application that need more resources, rather than scaling the entire application as a whole.

intermediate

Why is independent deployment important in microservices?

Independent deployment lets teams update or fix one service without affecting the entire system, reducing downtime and speeding up releases.

intermediate

What problem does microservices solve related to team organization?

Microservices allow different teams to own different services, enabling parallel development and reducing coordination overhead.

intermediate

How do microservices help with technology diversity?

Each microservice can use the best technology or programming language for its specific task, unlike monolithic apps that usually use one tech stack.

What is a key benefit of microservices over monolithic architecture?

A Less network communication

B Single codebase for all features

C Simpler deployment process

D Independent scaling of components

Microservices allow each component to scale independently, unlike monolithic systems which scale as a whole.

Why do microservices enable faster development cycles?

A Because services can be deployed independently

B Because all teams work on the same codebase

C Because microservices require fewer tests

D Because microservices use less code

Independent deployment means teams can release updates without waiting for the entire system to be ready.

Which problem is NOT directly solved by microservices?

A Reducing application complexity by splitting it

B Allowing different teams to work independently

C Eliminating the need for databases

D Supporting multiple technologies in one system

Microservices do not eliminate databases; each service may still use its own database or data store.

How do microservices affect fault isolation?

A Faults in one service can crash the entire system

B Faults are isolated to individual services

C Faults are harder to detect

D Faults are ignored by other services

Microservices isolate faults so a failure in one service does not bring down the whole system.

What is a common challenge introduced by microservices?

A Managing inter-service communication

B Writing code in one language

C Deploying a single executable

D Having a single database schema

Microservices require managing communication between services, which adds complexity.

Explain why microservices architecture was created and what problems it solves compared to monolithic systems.

Think about challenges in big apps and how splitting helps.

Describe the benefits and challenges of using microservices in software design.

Consider both what microservices improve and what new problems they bring.

Practice

1. Why do organizations choose microservices over a single large application?

easy

A. To write all code in one programming language

B. To make the system run only on one server

C. To avoid using any databases

D. To break a big system into smaller, manageable parts

Solution

1. Step 1: Understand the problem with large applications

   Large applications are hard to manage, update, and scale because everything is tightly connected.

2. Step 2: Identify microservices benefit

   Microservices split the big system into smaller parts that can be managed and updated independently.

3. Final Answer:

   To break a big system into smaller, manageable parts -> Option D

4. Quick Check:

   Microservices = smaller parts [OK]

Hint: Microservices split big apps into small parts [OK]

Common Mistakes:

• Thinking microservices run only on one server
• Believing microservices avoid databases
• Assuming microservices require one language

2. Which of the following is a key feature of microservices architecture?

easy

A. All services share the same database schema

B. Each service can be developed and deployed independently

C. Services must be written in the same programming language

D. Microservices require a monolithic deployment

Solution

1. Step 1: Review microservices independence

   Microservices allow teams to develop and deploy each service without affecting others.

2. Step 2: Check other options

   Sharing the same database or language is not required; monolithic deployment contradicts microservices.

3. Final Answer:

   Each service can be developed and deployed independently -> Option B

4. Quick Check:

   Independent deployment = microservices [OK]

Hint: Microservices = independent deploys [OK]

Common Mistakes:

• Assuming all services share one database
• Believing all code must be in one language
• Thinking microservices deploy as one unit

3. Consider a system split into microservices: User Service, Order Service, and Payment Service. If the Order Service crashes, what is the likely impact on the User Service?

medium

A. User Service continues working independently

B. User Service will lose all user data

C. User Service will also crash immediately

D. User Service will restart automatically

Solution

1. Step 1: Understand microservices isolation

   Each microservice runs independently, so failure in one does not crash others.

2. Step 2: Analyze impact on User Service

   User Service can keep working even if Order Service crashes, though some features may be limited.

3. Final Answer:

   User Service continues working independently -> Option A

4. Quick Check:

   Microservices isolation = independent operation [OK]

Hint: Microservices fail independently, not together [OK]

Common Mistakes:

• Assuming one service crash crashes all
• Thinking user data is lost when order fails
• Believing services auto-restart always

4. A team built a microservices system but notices that deploying one service requires stopping the entire system. What is the likely mistake?

medium

A. Services are tightly coupled and not independent

B. They are using too many programming languages

C. The database is too large

D. They did not write enough tests

Solution

1. Step 1: Identify deployment problem

   If deploying one service stops the whole system, services are not independent as microservices require.

2. Step 2: Rule out other options

   Programming languages, database size, or tests do not cause deployment to stop all services.

3. Final Answer:

   Services are tightly coupled and not independent -> Option A

4. Quick Check:

   Independent services = independent deploys [OK]

Hint: Independent deploy means no system-wide stop [OK]

Common Mistakes:

• Blaming programming languages for deployment issues
• Thinking database size causes deployment stop
• Assuming tests affect deployment independence

5. A company wants to scale their online store quickly during sales. How does microservices architecture help achieve this?

hard

A. By forcing all services to scale together as one unit

B. By allowing only the payment service to scale independently

C. By enabling each service to scale based on its own demand

D. By removing the need for any scaling

Solution

1. Step 1: Understand scaling in microservices

   Microservices let each part of the system scale separately depending on its load.

2. Step 2: Apply to online store scenario

   During sales, services like Order or Payment can scale more without scaling unrelated services.

3. Final Answer:

   By enabling each service to scale based on its own demand -> Option C

4. Quick Check:

   Microservices scale independently = efficient scaling [OK]

Hint: Scale each service separately for efficiency [OK]

Common Mistakes:

• Thinking only one service scales
• Believing all services must scale together
• Assuming microservices remove scaling needs