Explanation
While On-Demand mode is well-suited for unpredictable or bursty workloads, it is often cost-inefficient for applications with consistent throughput. Shifting to Provisioned mode with Auto Scaling enables baseline capacity configuration with incremental scaling, potentially yielding substantial cost reductions without performance compromise.
Relevant Billing Model
DynamoDB charges apply to reading, writing, and storing data, plus optional features like backups and global tables. Two pricing options exist:
- On-Demand Capacity Mode: Serverless pay-per-request pricing with automatic scaling, billed per request consumed.
- Provisioned Capacity Mode: Hourly charges based on configured read/write capacity regardless of actual usage, supporting Auto Scaling for dynamic adjustment.
Detection
- Identify tables configured for On-Demand capacity mode
- Review historical read/write activity for consistent or gradually increasing traffic patterns
- Evaluate whether workloads demonstrate steady throughput (regular APIs, background jobs, scheduled processing)
- Assess if baseline provisioned capacity meets typical demand with Auto Scaling handling fluctuations
- Check for operational, architectural, or application dependencies affecting mode switching
- Ensure meaningful, achievable cost savings based on usage trends
Remediation
For workloads with predictable usage patterns, transition the table to Provisioned capacity mode and enable Auto Scaling to dynamically adjust throughput within configured limits.