REL04-BP03: Do constant work
Overview
Implement constant work patterns to maintain consistent resource utilization and avoid the thundering herd problem that occurs when systems experience sudden spikes in demand. By performing work at a steady rate rather than in bursts, you can improve system predictability, reduce resource contention, and prevent cascading failures caused by sudden load changes.
Implementation Steps
1. Implement Steady-State Processing Patterns
- Design systems to process work at consistent rates
- Use background processing for non-urgent tasks
- Implement work smoothing algorithms to distribute load over time
- Avoid batch processing that creates resource spikes
2. Design Proactive Resource Management
- Pre-warm resources before they are needed
- Maintain connection pools at steady levels
- Implement predictive scaling based on patterns
- Use health checks and monitoring to maintain readiness
3. Implement Rate Limiting and Throttling
- Apply consistent rate limits to prevent sudden spikes
- Use token bucket algorithms for smooth traffic shaping
- Implement backpressure mechanisms to control flow
- Design adaptive throttling based on system capacity
4. Establish Predictable Caching Patterns
- Implement cache warming strategies
- Use consistent cache refresh patterns
- Avoid cache stampede scenarios
- Design cache hierarchies for predictable performance
5. Design Consistent Database Access Patterns
- Implement read-through and write-through caching
- Use connection pooling with steady connection counts
- Avoid batch operations that create resource spikes
- Implement consistent query patterns and indexing
6. Monitor and Optimize Work Distribution
- Track resource utilization patterns and identify spikes
- Implement metrics for work distribution consistency
- Use automated scaling based on steady-state metrics
- Optimize algorithms to maintain consistent performance
Implementation Examples
Example 1: Constant Work Processing System
AWS Services Used
- Amazon SQS: Message queuing with consistent polling patterns for steady work distribution
- AWS Lambda: Serverless functions with reserved concurrency for predictable execution
- Amazon CloudWatch: Monitoring and metrics for tracking work distribution patterns
- Amazon Kinesis: Stream processing with consistent shard allocation and processing
- AWS Step Functions: Workflow orchestration with consistent execution patterns
- Amazon DynamoDB: Database with consistent read/write patterns and auto-scaling
- Amazon ElastiCache: Caching with consistent connection pools and refresh patterns
- AWS Auto Scaling: Predictive scaling based on historical patterns
- Amazon EventBridge: Event processing with consistent rate limiting
- AWS Batch: Batch processing with steady job submission patterns
- Amazon ECS/EKS: Container orchestration with consistent resource allocation
- AWS Systems Manager: Parameter store for configuration management
- Amazon CloudFront: CDN with consistent cache warming patterns
- Elastic Load Balancing: Load balancing with consistent health checking
- AWS X-Ray: Distributed tracing for monitoring consistent performance patterns
Benefits
- Predictable Performance: Consistent resource utilization leads to predictable system behavior
- Reduced Resource Contention: Steady work patterns prevent resource spikes and contention
- Improved Scalability: Consistent load patterns enable better auto-scaling decisions
- Better Cost Management: Predictable resource usage enables better cost optimization
- Enhanced Reliability: Avoiding sudden spikes reduces the risk of cascading failures
- Simplified Monitoring: Consistent patterns make it easier to detect anomalies
- Better User Experience: Steady performance provides consistent response times
- Reduced Thundering Herd: Constant work patterns prevent sudden demand spikes
- Improved Resource Planning: Predictable patterns enable better capacity planning
- Enhanced System Stability: Consistent work distribution improves overall system stability
Related Resources
- AWS Well-Architected Reliability Pillar
- Do Constant Work
- Amazon SQS Best Practices
- AWS Lambda Concurrency
- Amazon CloudWatch User Guide
- AWS Auto Scaling User Guide
- Rate Limiting Patterns
- Thundering Herd Problem
- Amazon Kinesis Best Practices
- AWS Batch User Guide
- Predictive Scaling
- Building Resilient Systems