Microservices Architecture

Architecture

Build a microservices architecture on AWS ECS:

  • Service Isolation: Each microservice runs in its own ECS service
  • Independent Scaling: Scale each service based on its specific workload
  • Service Discovery: AWS Cloud Map enables service-to-service communication
  • Load Balancing: ALB routes traffic to appropriate services

When to Use

Microservices architecture is ideal when:

  • Your application can be decomposed into independent, loosely-coupled services
  • Different services have different scaling requirements
  • Teams need to deploy and update services independently
  • You want to use different technologies for different services
  • Fault isolation is important for your application

Considerations

Benefits

  • Team Autonomy: Different teams can own and deploy different services
  • Technology Flexibility: Each service can use the most appropriate runtime
  • Resilience: Failures in one service do not affect others
  • Scalability: Scale individual services based on demand

Challenges

  • Increased Complexity: More services mean more infrastructure to manage
  • Network Latency: Service-to-service communication adds latency
  • Distributed Tracing: Debugging requires tools like X-Ray
  • Data Consistency: Managing distributed data requires careful design

Example Configuration

# User service
module "user_service" {
  source  = "registry.patterneddesigns.ca/patterneddesigns/ecs-service/aws"
  version = "2.0.0"

  service_name        = "user-service"
  cluster_arn         = aws_ecs_cluster.main.arn
  task_definition_arn = aws_ecs_task_definition.user.arn
  desired_count       = 2

  service_discovery = {
    namespace_id = aws_service_discovery_private_dns_namespace.main.id
    dns_name     = "users"
  }
}

# Order service
module "order_service" {
  source  = "registry.patterneddesigns.ca/patterneddesigns/ecs-service/aws"
  version = "2.0.0"

  service_name        = "order-service"
  cluster_arn         = aws_ecs_cluster.main.arn
  task_definition_arn = aws_ecs_task_definition.order.arn
  desired_count       = 3

  service_discovery = {
    namespace_id = aws_service_discovery_private_dns_namespace.main.id
    dns_name     = "orders"
  }
}

# API Gateway service
module "api_gateway" {
  source  = "registry.patterneddesigns.ca/patterneddesigns/ecs-service/aws"
  version = "2.0.0"

  service_name        = "api-gateway"
  cluster_arn         = aws_ecs_cluster.main.arn
  task_definition_arn = aws_ecs_task_definition.gateway.arn
  desired_count       = 2

  load_balancer = {
    target_group_arn = aws_lb_target_group.gateway.arn
    container_name   = "gateway"
    container_port   = 8080
  }
}