orion/docs/architecture/capacity-planning.md

Capacity Planning & Infrastructure Sizing

This document provides comprehensive capacity planning guidelines for the Wizamart platform, including resource requirements, scaling thresholds, and monitoring recommendations.

Related: Pricing Strategy for tier definitions and limits

---

Tier Resource Allocations

Based on our pricing tiers, here are the expected resource requirements per client:

Metric	Essential (€49)	Professional (€99)	Business (€199)	Enterprise (€399+)
Products	200	500	2,000	Unlimited
Images per product	3	5	8	10+
Orders per month	100	500	2,000	Unlimited
SKU variants	1.2x	1.5x	2x	3x
Team members	1	3	10	Unlimited
API requests/day	1,000	5,000	20,000	Unlimited

---

Scale Projections

Target: 1,000 Business Clients (€149/month tier)

This represents our primary growth target. Here's the infrastructure impact:

Resource	Calculation	Total
Products	1,000 clients × 500 products	500,000
Product Translations	500,000 × 4 languages	2,000,000 rows
Images (files)	500,000 × 5 images × 3 sizes	7,500,000 files
Image Storage	7.5M files × 200KB avg	1.5 TB
Database Size	Products + translations + orders + indexes	15-25 GB
Monthly Orders	1,000 clients × 300 orders	300,000 orders
Order Items	300,000 × 2.5 avg items	750,000 items/month
Monthly API Requests	1,000 × 10,000 req/day × 30	300M requests

Multi-Tier Mix (Realistic Scenario)

More realistic distribution across tiers:

Tier	Clients	Products Each	Total Products	Monthly Orders
Essential	500	100	50,000	50,000
Professional	300	300	90,000	150,000
Business	150	1,000	150,000	300,000
Enterprise	50	3,000	150,000	200,000
Total	1,000	-	440,000	700,000

---

Server Sizing Recommendations

Infrastructure Tiers

Scale	Clients	vCPU	RAM	Storage	Database	Monthly Cost
Starter	1-50	2	4GB	100GB SSD	SQLite	€20-40
Small	50-100	4	8GB	250GB SSD	PostgreSQL	€60-100
Medium	100-300	4	16GB	500GB SSD	PostgreSQL	€100-180
Large	300-500	8	32GB	1TB SSD	PostgreSQL + Redis	€250-400
Scale	500-1000	16	64GB	2TB SSD + CDN	PostgreSQL + Redis	€500-900
Enterprise	1000+	32+	128GB+	4TB+ + CDN	PostgreSQL cluster	€1,500+

Recommended Configurations

Starter (1-50 clients)

Single Server Setup:
- Hetzner CX22 or similar (2 vCPU, 4GB RAM)
- 100GB SSD storage
- SQLite database
- nginx for static files + reverse proxy
- Estimated cost: €20-40/month

Small-Medium (50-300 clients)

Two-Server Setup:
- App Server: 4 vCPU, 8-16GB RAM
- Database: Managed PostgreSQL (basic tier)
- Storage: Local SSD + backup
- Optional: Redis for sessions/caching
- Estimated cost: €80-180/month

Large (300-1000 clients)

Multi-Component Setup:
- Load Balancer: nginx or cloud LB
- App Servers: 2-4 × (4 vCPU, 8GB RAM)
- Database: Managed PostgreSQL (production tier)
- Cache: Redis (managed or self-hosted)
- Storage: Object storage (S3-compatible) + CDN
- Estimated cost: €400-900/month

Enterprise (1000+ clients)

Full Production Setup:
- CDN: Cloudflare or similar
- Load Balancer: Cloud-native with health checks
- App Servers: 4-8 × (4 vCPU, 16GB RAM) with auto-scaling
- Database: PostgreSQL with read replicas
- Cache: Redis cluster
- Storage: S3 + CloudFront or equivalent
- Monitoring: Prometheus + Grafana
- Estimated cost: €1,500+/month

---

Image Storage Architecture

Capacity Calculations

Image Size (optimized)	Files per 25GB	Files per 100GB	Files per 1TB
100KB (thumbnails)	250,000	1,000,000	10,000,000
200KB (web-ready)	125,000	500,000	5,000,000
300KB (high quality)	83,000	333,000	3,330,000
500KB (original)	50,000	200,000	2,000,000

Image Sizes Generated

Each uploaded image generates 3 variants:

Variant	Dimensions	Typical Size	Use Case
thumb	200×200	10-20KB	List views, grids
medium	800×800	80-150KB	Product cards, previews
original	As uploaded	200-500KB	Detail views, zoom

Storage per product: ~600KB (with 3 sizes for main image + 2 additional images)

Directory Structure (Sharded)

To prevent filesystem performance degradation, images are stored in a sharded directory structure:

/uploads/
  └── products/
      ├── 00/                    # First 2 chars of hash
      │   ├── 1a/               # Next 2 chars
      │   │   ├── 001a2b3c_original.webp
      │   │   ├── 001a2b3c_800.webp
      │   │   └── 001a2b3c_200.webp
      │   └── 2b/
      │       └── ...
      ├── 01/
      └── ...

This structure ensures:

• Maximum ~256 subdirectories per level
• ~16 files per leaf directory at 1M total images
• Fast filesystem operations even at scale

Performance Thresholds

Files per Directory	Performance	Required Action
< 10,000	Excellent	None
10,000 - 100,000	Good	Monitor, plan sharding
100,000 - 500,000	Degraded	Implement sharding
> 500,000	Poor	Migrate to object storage

---

Database Performance

Table Size Guidelines

Table	Rows	Query Time	Status
< 10,000	< 1ms	Excellent
10,000 - 100,000	1-10ms	Good
100,000 - 1,000,000	10-50ms	Add indexes, optimize queries
1,000,000 - 10,000,000	50-200ms	Consider partitioning
> 10,000,000	Variable	Sharding or dedicated DB

Critical Indexes

Ensure these indexes exist at scale:

-- Products
CREATE INDEX idx_product_store_active ON products(store_id, is_active);
CREATE INDEX idx_product_gtin ON products(gtin);
CREATE INDEX idx_product_store_sku ON products(store_id, store_sku);

-- Orders
CREATE INDEX idx_order_store_status ON orders(store_id, status);
CREATE INDEX idx_order_created ON orders(created_at DESC);
CREATE INDEX idx_order_customer ON orders(customer_id);

-- Inventory
CREATE INDEX idx_inventory_product_location ON inventory(product_id, warehouse, bin_location);
CREATE INDEX idx_inventory_store ON inventory(store_id);

Database Size Estimates

Component	Size per 100K Products	Size per 1M Products
Products table	100 MB	1 GB
Translations (4 langs)	400 MB	4 GB
Orders (1 year)	500 MB	5 GB
Order items	200 MB	2 GB
Inventory	50 MB	500 MB
Indexes	300 MB	3 GB
Total	~1.5 GB	~15 GB

---

Bandwidth & Network

Monthly Bandwidth Estimates (1000 clients)

Traffic Type	Calculation	Monthly Volume
Image views	500K products × 10 views × 500KB	2.5 TB
API requests	10K req/client/day × 1000 × 30 × 2KB	600 GB
Static assets	CSS/JS cached, minimal	50 GB
Total Egress		~3 TB/month

Bandwidth Costs (Approximate)

Provider	First 1TB	Additional per TB
Hetzner	Included	€1/TB
AWS	$90	$85/TB
DigitalOcean	1TB free	$10/TB
Cloudflare	Unlimited (CDN)	Free

Recommendation: Use Cloudflare for image CDN to eliminate egress costs.

---

Scaling Triggers & Thresholds

When to Scale Up

Metric	Warning	Critical	Action
CPU Usage	> 70% avg	> 85% avg	Add app server
Memory Usage	> 75%	> 90%	Upgrade RAM or add server
Disk Usage	> 70%	> 85%	Expand storage
DB Query Time (p95)	> 100ms	> 500ms	Optimize queries, add indexes
API Response Time (p95)	> 500ms	> 2000ms	Scale horizontally
DB Connections	> 80% max	> 95% max	Add connection pooling
Error Rate	> 1%	> 5%	Investigate and fix

Architecture Transition Points

STARTER → SMALL (50 clients)
├── Trigger: SQLite becomes bottleneck
├── Action: Migrate to PostgreSQL
└── Cost increase: +€40-60/month

SMALL → MEDIUM (100 clients)
├── Trigger: Single server at 70%+ CPU
├── Action: Separate DB server
└── Cost increase: +€50-80/month

MEDIUM → LARGE (300 clients)
├── Trigger: Need for caching, higher availability
├── Action: Add Redis, consider multiple app servers
└── Cost increase: +€150-200/month

LARGE → SCALE (500 clients)
├── Trigger: Storage >500GB, high traffic
├── Action: Object storage + CDN, load balancing
└── Cost increase: +€200-400/month

SCALE → ENTERPRISE (1000+ clients)
├── Trigger: High availability requirements, SLA
├── Action: Full redundancy, read replicas, auto-scaling
└── Cost increase: +€600-1000/month

---

Monitoring Requirements

Essential Metrics

Track these metrics for capacity planning:

Infrastructure

• CPU utilization (per server)
• Memory utilization
• Disk I/O and usage
• Network throughput

Application

• Request latency (p50, p95, p99)
• Request rate (per endpoint)
• Error rate by type
• Active sessions

Database

• Query execution time
• Connection pool usage
• Table sizes
• Index usage

Business

• Active clients
• Products per client
• Orders per day
• API calls per client

Monitoring Dashboard

The admin platform includes a Capacity Monitoring page at /admin/platform-health with:

1. Current Usage - Real-time resource utilization
2. Growth Trends - Historical charts for planning
3. Threshold Alerts - Warning and critical indicators
4. Scaling Recommendations - Automated suggestions

See Platform Health Monitoring section below.

---

Cost Analysis

Infrastructure Cost per Client

Scale	Clients	Monthly Infra	Cost/Client
Starter	25	€30	€1.20
Small	75	€80	€1.07
Medium	200	€150	€0.75
Large	400	€350	€0.88
Scale	800	€700	€0.88
Enterprise	1500	€1,800	€1.20

Revenue vs Infrastructure Cost

At 1,000 Business tier clients (€149/month):

Item	Monthly
Revenue	€149,000
Infrastructure	€700-900
Support (est.)	€3,000
Development (est.)	€5,000
Gross Margin	~96%

---

Disaster Recovery

Backup Strategy by Scale

Scale	Database Backup	File Backup	RTO	RPO
Starter	Daily SQLite copy	Daily rsync	4h	24h
Small	Daily pg_dump	Daily sync	2h	12h
Medium	Managed backups	S3 versioning	1h	6h
Large	Point-in-time	S3 + cross-region	30m	1h
Enterprise	Streaming replicas	Multi-region	5m	5m

---

Platform Health Monitoring

The admin dashboard includes a dedicated capacity monitoring page that tracks:

Metrics Displayed

1. Client Growth

   • Total active clients
   • New clients this month
   • Churn rate

2. Resource Usage

   • Total products across all stores
   • Total images stored
   • Database size
   • Storage usage

3. Performance Indicators

   • Average API response time
   • Database query latency
   • Error rate

4. Threshold Status

   • Current infrastructure tier
   • Distance to next threshold
   • Recommended actions

Alert Configuration

Configure alerts for proactive scaling:

CAPACITY_THRESHOLDS = {
    "products_total": {
        "warning": 400_000,   # 80% of 500K
        "critical": 475_000,  # 95% of 500K
    },
    "storage_gb": {
        "warning": 800,       # 80% of 1TB
        "critical": 950,
    },
    "db_size_gb": {
        "warning": 20,
        "critical": 24,
    },
    "avg_response_ms": {
        "warning": 200,
        "critical": 500,
    },
}

---

Quick Reference

TL;DR Sizing Guide

Clients	Server	RAM	Storage	Database	Monthly Cost
1-50	2 vCPU	4GB	100GB	SQLite	€30
50-100	4 vCPU	8GB	250GB	PostgreSQL	€80
100-300	4 vCPU	16GB	500GB	PostgreSQL	€150
300-500	8 vCPU	32GB	1TB	PostgreSQL + Redis	€350
500-1000	16 vCPU	64GB	2TB + CDN	PostgreSQL + Redis	€700
1000+	32+ vCPU	128GB+	4TB+ + CDN	PostgreSQL cluster	€1,500+

Key Formulas

Storage (GB) = (Products × Images × 3 sizes × 200KB) / 1,000,000
DB Size (GB) = Products × 0.00003 + Orders × 0.00002
Bandwidth (TB/mo) = Products × Daily Views × 500KB × 30 / 1,000,000,000

---

See Also

• Pricing Strategy - Tier definitions and limits
• Multi-Tenant Architecture - How client isolation works
• Background Tasks - Task queue scaling
• Production Deployment - Deployment guidelines