WebCost & UsageOptimization
Optimization Views
The Optimization section at /cost-and-usage/optimization provides four analytical views for identifying cost reduction opportunities and usage anomalies. Each view addresses a specific dimension of cloud spending efficiency.
Indicators View
The Indicators view presents three gauge cards that summarize the most critical efficiency signals at a glance:
| Indicator | Calculation | Good Range |
|---|---|---|
| Idle Spend % | Cost attributed to resources with zero usage in the period | < 5% |
| Overprovisioning | Resources with average CPU or memory utilization below threshold (Compute Optimizer signal) | < 15% |
| Usage Concentration | Percentage of total cost from the top 10 resources (Pareto measure) | 60–80% |
Baseline View (Anomaly Detection)
The Baseline view renders a Z-score anomaly detection chart using a 14-day rolling window:
- Baseline band: Calculated from days D-16 to D-3 (excluding the most recent 2 days to avoid recency bias)
- Expected range: Mean ± (2 × standard deviation) drawn as a shaded band
- Anomaly markers: Points outside the band are flagged in red. Z-score threshold is configurable (default: 2.0)
- Dimension filtering: Same dimension selector as Unit Cost — pivot by service, region, resource, or tag
Stability View
The Stability view is a scatter plot that maps each resource or service grouping onto a two-axis space:
- X-axis: Coefficient of Variation (CV = std dev / mean) — measures usage predictability. Lower CV means more stable, predictable usage.
- Y-axis: Cost magnitude (total spend in period)
- Commitment zone: Resources in the low-CV, high-cost quadrant are ideal candidates for Reserved Instances or Savings Plans
Hovering a dot shows the resource name, CV value, and estimated annual savings from a 1-year commitment.
Advanced View
The Advanced view consolidates four specialized visualizations in a single scrollable page:
| Component | Description |
|---|---|
| Calendar Heatmap | Month-view heatmap coloring each day by spend. Idle days (zero spend) shown in grey. Helps spot weekday vs. weekend patterns. |
| Zero-Query Days | Count of days in the period where Redshift received zero queries. Indicates cluster idle time — a prime candidate for scheduled pausing. |
| Off-Hours Donut | Percentage of total spend occurring outside business hours (configurable: default 6 PM–8 AM and weekends). High off-hours spend may indicate runaway jobs. |
| Underutilized Clusters | Table of Redshift clusters with average query time <5 minutes and <10 queries/day in the period — candidates for downsizing. |
Configuration
All optimization thresholds (idle spend threshold, Z-score cutoff, business hours definition, CV bucket boundaries) are configurable via
/cost-and-usage/config. Changes apply to all four views immediately on save.