REL04-BP01: Identify the kind of distributed systems you depend on

Overview

Systematically identify and catalog all distributed systems, services, and dependencies that your workload relies upon to understand failure modes, communication patterns, and reliability characteristics. This comprehensive understanding enables you to design appropriate resilience patterns, implement proper monitoring, and establish effective failure handling strategies for each type of distributed system interaction.

Implementation Steps

1. Conduct Comprehensive Dependency Discovery

Map all external service dependencies and their characteristics
Identify synchronous and asynchronous communication patterns
Catalog third-party services, APIs, and external data sources
Document internal microservices and their interdependencies

2. Classify Distributed System Types and Patterns

Categorize dependencies by communication patterns and reliability characteristics
Identify request-response, publish-subscribe, and event-driven patterns
Classify services by criticality and failure impact
Document data consistency requirements and transaction boundaries

3. Analyze Failure Modes and Impact

Identify potential failure scenarios for each dependency type
Assess cascading failure risks and blast radius
Evaluate timeout, retry, and circuit breaker requirements
Document recovery time objectives and acceptable degradation levels

4. Implement Dependency Monitoring and Observability

Deploy comprehensive monitoring for all identified dependencies
Implement distributed tracing across service boundaries
Establish health checks and dependency status monitoring
Create dashboards and alerting for dependency failures

5. Design Resilience Patterns for Each Dependency Type

Implement appropriate resilience patterns based on dependency characteristics
Configure circuit breakers, bulkheads, and timeout strategies
Design fallback mechanisms and graceful degradation
Establish retry policies and backoff strategies

6. Establish Dependency Governance and Documentation

Create and maintain dependency catalogs and documentation
Implement dependency approval and review processes
Establish SLA requirements and monitoring for critical dependencies
Create runbooks and incident response procedures
Implementation Examples

Example 1: Distributed Systems Discovery and Analysis Engine

Example 2: Distributed Systems Discovery Script

AWS Services Used

AWS X-Ray: Distributed tracing to identify service dependencies and communication patterns
Amazon CloudWatch: Monitoring and metrics collection for dependency health and performance
AWS Systems Manager: Service discovery and configuration management for internal dependencies
Amazon API Gateway: API management and monitoring for service-to-service communication
AWS Lambda: Serverless functions for dependency health checks and monitoring
Amazon RDS: Relational database services with connection pooling and failover capabilities
Amazon DynamoDB: NoSQL database with built-in resilience and scaling capabilities
Amazon ElastiCache: In-memory caching layer for reducing dependency load
Amazon SQS: Message queuing for asynchronous communication patterns
Amazon SNS: Publish-subscribe messaging for event-driven architectures
AWS Step Functions: Workflow orchestration for complex distributed processes
Amazon EventBridge: Event routing and processing for loosely coupled systems
AWS App Mesh: Service mesh for microservices communication and observability
Amazon ECS/EKS: Container orchestration with service discovery and load balancing
Elastic Load Balancing: Load distribution and health checking for service endpoints
AWS Config: Configuration tracking and compliance monitoring for dependencies

Benefits

Comprehensive Visibility: Complete understanding of all distributed system dependencies
Proactive Risk Management: Early identification of potential failure points and risks
Informed Architecture Decisions: Data-driven decisions about resilience patterns and strategies
Improved Incident Response: Better understanding of failure impact and recovery procedures
Optimized Performance: Identification of bottlenecks and optimization opportunities
Enhanced Monitoring: Targeted monitoring and alerting for critical dependencies
Risk Assessment: Quantified analysis of failure modes and business impact
Compliance Support: Documentation and tracking of system dependencies for audits
Team Alignment: Shared understanding of system architecture and dependencies
Continuous Improvement: Regular assessment and optimization of distributed system design