Microservices Architecture

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What Are Microservices?

Microservices architecture breaks down a large system into smaller, more manageable components. Each microservice is designed to do one thing well and can be developed, deployed, and scaled independently.

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Typical Microservice Architecture

The diagram above shows a typical microservice architecture with all essential components.

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Key Components

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Load Balancer

Distributes incoming traffic across multiple backend services ensuring:

• High availability
• Fault tolerance
• Optimal resource utilization
• Better response times

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CDN (Content Delivery Network)

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API Gateway

Handles incoming requests and routes them to the relevant services. It communicates with:

• Identity provider for authentication
• Service discovery for routing
• Backend microservices

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Service Registry & Discovery

How Service Discovery Works

Microservice registration and discovery happen in this component. The API gateway looks for relevant services in this component to communicate.Common Tools:

• Consul
• Eureka
• Zookeeper
• Kubernetes Services

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9 Best Practices for Building Microservices

Creating a system using microservices is extremely difficult unless you follow strong principles.

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1. Design For Failure

Strategies:

• Implement circuit breakers
• Use bulkheads for isolation
• Apply graceful degradation methods
• Design for redundancy
• Plan for chaos engineering

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2. Build Small Services

Single Responsibility Benefits:

• Easier to understand and maintain
• Faster to develop and deploy
• Independent scaling
• Team ownership clarity

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3. Use Lightweight Protocols for Communication

Communication is the core of a distributed system. Microservices must talk to each other using lightweight protocols.

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4. Implement Service Discovery

To communicate with each other, microservices need to discover each other over the network. Tools:

• Consul
• Eureka
• Zookeeper
• Kubernetes Services
• etcd

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5. Data Ownership

Database Per Service Pattern

In microservices, data should be owned and managed by the individual services.Goal: Reduce coupling between services so they can evolve independently.Benefits:

• Independent data schema evolution
• Technology choice flexibility
• Better scalability
• Clear ownership boundaries

Challenges:

• Data consistency across services
• Complex queries spanning services
• Distributed transactions

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6. Use Resiliency Patterns

Implement specific resiliency patterns to improve service availability.

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7. Security at All Levels

Security Layers:

• API Gateway authentication/authorization
• Service-to-service authentication (mTLS)
• Data encryption in transit and at rest
• Secret management
• Network segmentation
• API rate limiting

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8. Centralized Logging

Logging Stack:

• Collection: Logstash, Fluentd
• Storage: Elasticsearch, S3
• Visualization: Kibana, Grafana
• Analysis: Distributed tracing (Jaeger, Zipkin)

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9. Use Containerization Techniques

To deploy microservices in an isolated manner, use containerization techniques. Benefits:

• Consistent environments
• Easy scaling
• Resource isolation
• Simplified deployment

Tools:

• Docker - Container runtime
• Kubernetes - Container orchestration
• Helm - Package management
• Docker Compose - Local development

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9 Essential Production Components

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1. API Gateway

Provides a unified entry point for client applications. Handles:

• Routing
• Filtering
• Load balancing
• Authentication
• Rate limiting

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2. Service Registry

Contains the details of all services. The gateway discovers services using the registry. Options:

• Consul
• Eureka
• Zookeeper
• etcd

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3. Service Layer

Each microservice serves a specific business function and can run on multiple instances.

Framework Options

Java/JVM:

• Spring Boot
• Quarkus
• Micronaut

Node.js:

• NestJS
• Express
• Fastify

Go:

• Go Kit
• Micro
• Gin

Python:

• FastAPI
• Flask
• Django

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4. Authorization Server

Secures microservices and manages identity and access control. Solutions:

• Keycloak
• Azure AD
• Okta
• Auth0

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5. Data Storage

Databases store application data generated by services.

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6. Distributed Caching

Caching boosts application performance significantly. Options:

• Redis
• Memcached
• Couchbase
• Hazelcast

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7. Async Microservices Communication

Platforms:

• Apache Kafka
• RabbitMQ
• Amazon SQS
• Google Pub/Sub

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8. Metrics Visualization

Microservices publish metrics for monitoring and alerting. Stack:

• Collection: Prometheus
• Visualization: Grafana
• Alerting: Alertmanager

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9. Log Aggregation and Visualization

Logs generated by services need to be aggregated and analyzed. ELK Stack:

• Logstash - Aggregation
• Elasticsearch - Storage
• Kibana - Visualization

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Orchestration vs. Choreography

How do microservices collaborate and interact with each other? There are two approaches:

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Choreography

How Choreography Works

Like having a choreographer set all the rules, then the dancers (microservices) interact according to them. Service choreography describes the exchange of messages and the rules by which microservices interact.Benefits:

• Loose coupling
• No central point of failure
• Services are autonomous

Challenges:

• Complex fault tolerance scenarios
• Difficult to understand overall flow
• Harder to modify interactions

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Orchestration

Benefits:

• Reliability - Built-in transaction management and error handling
• Scalability - Only the orchestrator needs modification when adding new services
• Visibility - Central view of the workflow

Limitations:

• Performance - Higher latency through centralized communication
• Single point of failure - Orchestrator must be highly available

Real-world Example: Netflix Conductor is a microservice orchestrator.

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When NOT to Use Microservices

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Applications That Should Avoid Microservices:

1. Real-time Gaming

• Requires millisecond-level latency
• Network latency is unbearable
• State must be stored in memory for quick updates
• Needs web socket connections and sticky routing

2. Low-latency Trading

• Requires microsecond-level latency
• Cannot separate services into different processes
• Needs in-memory state storage
• High-frequency server communication required

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Common Features Requiring Monolithic Architecture:

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Best Practices Summary

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Next Steps