Capacity Planning Helper Right-size infrastructure for current and future needs. Traffic Forecasting interface TrafficForecast { current : { dailyUsers : number ; peakRPS : number ; avgRPS : number ; } ; projected : { timeframe : "6m" | "12m" | "24m" ; dailyUsers : number ; peakRPS : number ; avgRPS : number ; growthRate : number ; } ; } const forecast : TrafficForecast = { current : { dailyUsers : 100000 , peakRPS : 500 , avgRPS : 200 , } , projected : { timeframe : "12m" , dailyUsers : 500000 , // 5x growth peakRPS : 2500 , avgRPS : 1000 , growthRate : 4.0 , // 400% growth } , } ; Resource Estimation interface ResourceNeeds { compute : { instanceType : string ; instanceCount : number ; cpu : number ; memory : number ; } ; database : { instanceType : string ; instanceCount : number ; storage : number ; iops : number ; } ; cache : { instanceType : string ; nodes : number ; memory : number ; } ; } function estimateResources ( forecast : TrafficForecast ) : ResourceNeeds { const { peakRPS } = forecast . projected ; // Rule of thumb: 100 RPS per instance (with headroom) const instanceCount = Math . ceil ( peakRPS / 100 ) ; // Database: 1000 connections per 2vCPU const dbInstances = Math . ceil ( ( peakRPS * 2 ) / 1000 ) ; return { compute : { instanceType : "t3.large" , instanceCount : instanceCount * 1.5 , // 50% headroom cpu : 2 * instanceCount , memory : 8 * instanceCount , } , database : { instanceType : "db.r6g.xlarge" , instanceCount : dbInstances , storage : 1000 , // GB iops : 10000 , } , cache : { instanceType : "cache.r6g.large" , nodes : 2 , // Primary + replica memory : 12 , // GB } , } ; } Cost Estimation interface CostEstimate { monthly : { compute : number ; database : number ; cache : number ; storage : number ; bandwidth : number ; total : number ; } ; annual : number ; } const pricing = { "t3.large" : 0.0832 , // $/hour "db.r6g.xlarge" : 0.336 , "cache.r6g.large" : 0.226 , storage : 0.1 , // $/GB/month bandwidth : 0.09 , // $/GB } ; function estimateCost ( resources : ResourceNeeds , trafficGB : number ) : CostEstimate { const hoursPerMonth = 730 ; const monthly = { compute : resources . compute . instanceCount * pricing [ "t3.large" ] * hoursPerMonth , database : resources . database . instanceCount * pricing [ "db.r6g.xlarge" ] * hoursPerMonth , cache : resources . cache . nodes * pricing [ "cache.r6g.large" ] * hoursPerMonth , storage : resources . database . storage * pricing . storage , bandwidth : trafficGB * pricing . bandwidth , total : 0 , } ; monthly . total = Object . values ( monthly ) . reduce ( ( sum , cost ) => sum + cost , 0 ) ; return { monthly , annual : monthly . total * 12 , } ; } Scale Triggers

auto-scaling-config.yml

scaling : triggers : - metric : cpu_utilization threshold : 70% action : scale_up cooldown : 5m - metric : cpu_utilization threshold : 30% action : scale_down cooldown : 15m - metric : request_queue_depth threshold : 1000 action : scale_up cooldown : 1m limits : min_instances : 2 max_instances : 20 schedule :

Pre-scale for known traffic patterns

- time : "08:00" target_instances : 10 - time : "22:00" target_instances : 4 Cost/Performance Tradeoffs

Infrastructure Options

Option 1: Cost-Optimized ($2,500/mo)

Compute: 4x t3.large

Database: 1x db.r6g.large

Cache: 1x cache.r6g.medium

** Pros: ** Lowest cost - ** Cons: ** Limited headroom, potential latency issues

Option 2: Balanced ($5,000/mo)

Compute: 8x t3.large

Database: 2x db.r6g.xlarge

Cache: 2x cache.r6g.large

** Pros: ** Good headroom, redundancy - ** Cons: ** Moderate cost

Option 3: Performance-Optimized ($10,000/mo)

Compute: 12x c6g.xlarge

Database: 3x db.r6g.2xlarge

Cache: 3x cache.r6g.xlarge

** Pros: ** Maximum performance, high availability - ** Cons: ** Higher cost

Recommendation Start with Option 2, monitor for 1 month, adjust based on: - Actual CPU/memory utilization - Database query performance - Cache hit rates Capacity Planning Spreadsheet | Metric | Current | 6mo Proj | 12mo Proj | Notes | |---------------------|---------|----------|-----------|--------------------------| | Daily Users | 100k | 250k | 500k | 5x growth expected | | Peak RPS | 500 | 1250 | 2500 | Linear w/ users | | DB Connections | 100 | 250 | 500 | 2 per instance | | Storage (GB) | 100 | 300 | 1000 | User data + logs | | Bandwidth (TB) | 1 | 3 | 10 | Images + video | | Instance Count | 4 | 10 | 20 | Auto-scaling | | Monthly Cost | $2k | $5k | $10k | AWS estimate | Output Checklist Traffic forecast Resource estimates Cost analysis Scale triggers Performance targets Growth plan ENDFILE