Capacity Planning

Workflows

• Baseline: Measure current resource usage

• Forecast: Project future growth

• Size: Calculate required resources

• Buffer: Add headroom for spikes

• Monitor: Track actual vs. predicted

Key Metrics

Compute

• CPU utilization (target: 60-70%)

• Memory usage

• Request latency (P50, P95, P99)

Storage

• Disk IOPS

• Throughput (MB/s)

• Capacity growth rate

Network

• Bandwidth utilization

• Connection counts

• Packet loss

Estimation Framework

Little's Law

L = λ × W

L = Average number of items in system λ = Average arrival rate W = Average time in system

Example Calculation

Given:

• 1000 requests/second
• 100ms average response time

Required concurrent connections: L = 1000 × 0.1 = 100 concurrent connections

Resource Sizing

Database Connections

connections = (requests_per_second × avg_query_time) × 1.5

Memory

memory = (concurrent_users × memory_per_user) + base_overhead

CPU Cores

cores = (peak_rps × cpu_time_per_request) / target_utilization

Growth Planning

Traffic Growth

• Historical growth rate

• Planned marketing/launches

• Seasonal patterns

Data Growth

• Records per day

• Record size

• Retention policy

Capacity Planning Document

• Current state metrics

• Growth assumptions

• Resource projections (3, 6, 12 months)

• Cost estimates

• Scaling triggers and thresholds