Design and Data Management

1. Single Responsibility Principle (SRP)

2. Independence

3. Decentralized Data Management

4. Resilience

5. API-First Communication

Give the characteristics of Well-Designed Microservices (SIDRA)

Single Responsibility Principle (SRP)

Each microservice should focus on a single capability or responsibility.

Independence

Services should be independently deployable and testable.

Decentralized Data Management

Each microservice owns its data.

Resilience

Failures in one service should not

crash the entire system.

API-First communication

Services interact via

APIs (REST, gRPC, GraphQL, Messaging Queues).

Domain-Driven Design (DDD)

Identify business domains and subdomains

Bounded Contexts

Group related functionality (e.g., Order service, payment service)

Synchronous Communication

A request/response communication style where a service waits for an immediate reply (e.g., REST, gRPC).

Asynchronous Communication

An event-driven communication style where services communicate through messages without waiting for immediate responses.

Prefer async messaging to reduce tight coupling

What is the best practice for communication patterns?

Containerization

Packaging applications and dependencies into containers using tools like Docker.

Auto-scaling

Automatically increasing or decreasing service instances based on workload demand.

Monolithic systems

single database for all modules.

Strong consistency

A consistency model where data changes are immediately visible to all services but can limit scalability.

Eventual Consistency

A model where data updates propagate asynchronously and eventually become consistent across services.

Sagas pattern

Long-running transactions split across multiple services. Coordination via: Choreography and Orchestration

CQRS (Command Query Responsibility Segregation):

Separate read and write models for efficiency

Event sourcing

Store changes as a sequence of events rather than

current state.

1. API Composition

2. Database View Replication

3. Event-Driven Replication

Give the 3 Data Sharing Strategies (ADE)

API Composition

A data sharing strategy where a service aggregates data from multiple services through APIs.

Database View Replication

Creating read-only replicated views of data for reporting or querying.

Event-Driven Data Replication

Services publish events so other services can update their own data stores.

Polyglot Persistence

Using different types of databases for different microservices depending on their needs.

Authentication

The process of verifying the identity of a user or service.

Data Security

Encrypt sensitive data at rest and in transit.

Governance

API Gateway for access control, monitoring,

throttling.