Database per service pattern in Microservices - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Why use the database per service pattern in microservices?

In a microservices architecture, why is it beneficial for each service to have its own database?

A It allows each service to be independently developed, deployed, and scaled without affecting others.

B It forces all services to share the same data schema, improving consistency.

C It reduces the total number of databases needed, lowering infrastructure costs.

D It ensures that all services access data through a single centralized database.

💡 Hint

Think about how independent services should be in microservices.

Each microservice having its own database allows it to evolve independently, avoiding tight coupling and enabling independent scaling and deployment.

❓ Architecture

intermediate

Identify the correct architecture for database per service pattern

Which diagram best represents the database per service pattern in microservices?

A All services connected to a central database cluster with shared tables.

B Multiple services connected to a single shared database instance.

C Multiple services each connected to their own separate database instances.

D One service connected to multiple databases, other services share one database.

💡 Hint

Remember the pattern means each service owns its data store.

In the database per service pattern, each microservice manages its own database, ensuring loose coupling and autonomy.

❓ scaling

advanced

Scaling challenges with database per service pattern

What is a common scaling challenge when using the database per service pattern?

A High risk of single point of failure because all services use one database.

B Difficulty in maintaining data consistency across multiple databases owned by different services.

C Inability to scale services independently due to shared database bottlenecks.

D Services cannot be deployed independently because they share the same database schema.

💡 Hint

Think about data that spans multiple services.

Because each service has its own database, keeping data consistent across services requires careful design, often using eventual consistency or event-driven approaches.

❓ tradeoff

advanced

Tradeoffs of database per service pattern

Which of the following is a tradeoff when adopting the database per service pattern?

A Improved service autonomy but increased complexity in cross-service queries.

B Simplified data management but reduced service independence.

C Lower infrastructure costs but higher risk of data corruption.

D Centralized data control but slower service deployment.

💡 Hint

Consider what happens when services need data from each other.

While each service controls its own data, querying across services becomes complex and may require additional mechanisms like APIs or event messaging.

❓ estimation

expert

Estimating database instances for microservices

You have 10 microservices, each following the database per service pattern. Each service requires 2 database instances for high availability. How many total database instances are needed?

A 10

B 12

C 30

D 20

💡 Hint

Multiply the number of services by the number of instances per service.

Each of the 10 services needs 2 instances, so total instances = 10 * 2 = 20.