# Semiont Scaling Guide

This document describes how the Semiont semantic knowledge platform architecture will grow in response to various scaling factors and provides cost models for different user populations.

For real-time scaling signals, the OTel metrics described in
[Observability](./OBSERVABILITY.md) are the authoritative source —
particularly `semiont.job.queue.size` (worker fan-out trigger),
`semiont.handler.duration` (per-actor latency), and
`semiont.sse.subscribers` (concurrent client load).

## Architecture Scaling Patterns

### Response to More Users

**10 Users (Initial Deployment)**

- Single ECS task (512 CPU, 1024 MB memory)
- RDS t3.micro single-AZ
- Basic CloudWatch monitoring
- EFS for shared file storage

**100 Users**

- Scale to 2-3 ECS tasks
- Upgrade to RDS t3.small
- Enable RDS Performance Insights
- Add CloudFront caching optimizations

**1,000 Users**

- Auto-scaling group: 3-8 ECS tasks
- RDS t3.medium with Multi-AZ
- Implement Redis/ElastiCache for session storage
- S3 Intelligent Tiering
- Enhanced monitoring and alerting

**10,000 Users**

- Auto-scaling: 8-20 ECS tasks across multiple AZs
- RDS r6g.large with read replicas
- Separate ECS cluster for background jobs
- CloudFront with additional edge locations
- Application-level caching (APCu, Redis)

**100,000 Users**

- Auto-scaling: 20-50 ECS tasks
- RDS r6g.xlarge with multiple read replicas
- Database sharding considerations
- CDN optimization for global users
- Load balancer in multiple regions

**1,000,000 Users**

- Multi-region deployment
- Database clustering (Aurora Serverless v2)
- Microservices architecture split
- Advanced caching layers
- Global CDN with custom behaviors

**100,000,000+ Users**

- Multi-cloud/hybrid deployment
- Distributed database architecture
- Container orchestration with EKS
- Advanced observability and monitoring
- Edge computing for content delivery

### Response to More API Traffic

**Low Traffic (<1,000 API calls/day)**

- Default configuration sufficient
- Basic CloudFront caching (24hr TTL)
- Single ECS task can handle load

**Medium Traffic (1,000-10,000 API calls/day)**

- Increase ECS task memory to 2048MB
- Optimize CloudFront caching policies
- Enable API response caching in backend
- Monitor ALB response times

**High Traffic (10,000-100,000 API calls/day)**

- Auto-scaling based on ALB request count
- Implement application-level caching
- Database connection pooling
- CloudFront edge caching optimizations

**Very High Traffic (100,000+ API calls/day)**

- Dedicated read-only database replicas
- Advanced caching strategies (Varnish, Redis)
- CDN for all static assets
- Database query optimization

### Response to More Content Updates

**Light Content Updates (<10/day)**

- Default backup strategy (7-day retention)
- Standard EFS throughput mode
- Basic audit logging

**Moderate Updates (10-100/day)**

- Increase database IOPS allocation
- Enable S3 versioning with lifecycle policies
- Enhanced audit logging and change tracking
- Database backup optimization

**Heavy Updates (100-1,000/day)**

- Dedicated write database instance
- Real-time change replication
- Advanced EFS storage management
- Database partitioning strategies

**Enterprise Updates (1,000+/day)**

- Master-slave database architecture
- Change data capture (CDC) implementation
- Content versioning and rollback systems
- Advanced workflow management

## Cost Models by User Population

### 10 Users - Startup Configuration

**Monthly AWS Costs (us-east-1):**

| Service | Configuration | Monthly Cost |
|---------|--------------|--------------|
| RDS PostgreSQL | t3.micro, single-AZ, 20GB GP2 | $20 |
| ECS Fargate | 2 tasks (frontend + backend), 256 CPU, 512MB each | $18 |
| ALB | Standard configuration | $20 |
| NAT Gateway | 2 AZs, minimal data transfer | $45 |
| CloudFront | <1GB transfer, minimal requests | $5 |
| EFS Storage | <10GB, standard throughput | $3 |
| Secrets Manager | 5 secrets (DB, JWT, OAuth, App) | $5 |
| CloudWatch | Basic metrics and logs | $5 |
| **Total** | | **~$121/month** |

### 100 Users - Small Business

**Monthly AWS Costs:**

| Service | Configuration | Monthly Cost |
|---------|--------------|--------------|
| RDS PostgreSQL | t3.small, single-AZ, 50GB GP2 | $40 |
| ECS Fargate | 4-6 tasks (2-3 per service), 512 CPU, 1024MB | $72 |
| ALB | Increased request volume | $25 |
| NAT Gateway | Moderate data transfer | $55 |
| CloudFront | ~10GB transfer | $15 |
| EFS Storage | ~50GB, standard throughput | $15 |
| Secrets Manager | 5 secrets | $5 |
| CloudWatch | Enhanced monitoring | $15 |
| **Total** | | **~$242/month** |

### 1,000 Users - Growing Organization

**Monthly AWS Costs:**

| Service | Configuration | Monthly Cost |
|---------|--------------|--------------|
| RDS PostgreSQL | t3.medium, Multi-AZ, 100GB GP2 | $120 |
| ECS Fargate | 6-16 tasks (3-8 per service) auto-scaling | $360 |
| ALB | High request volume | $35 |
| NAT Gateway | Higher data transfer | $80 |
| CloudFront | ~100GB transfer | $50 |
| EFS Storage | ~200GB, provisioned throughput | $45 |
| ElastiCache | Redis t3.micro for caching | $25 |
| Secrets Manager | 5 secrets | $5 |
| CloudWatch | Detailed monitoring & alarms | $30 |
| **Total** | | **~$750/month** |

### 10,000 Users - Medium Enterprise

**Monthly AWS Costs:**

| Service | Configuration | Monthly Cost |
|---------|--------------|--------------|
| RDS PostgreSQL | r6g.large, Multi-AZ, 500GB GP3 | $400 |
| RDS Read Replicas | 2x r6g.medium read replicas | $320 |
| ECS Fargate | 16-40 tasks (8-20 per service) auto-scaling | $1,200 |
| ALB | Very high request volume | $60 |
| NAT Gateway | High data transfer | $120 |
| CloudFront | ~1TB transfer, global | $150 |
| EFS Storage | ~1TB, provisioned throughput | $180 |
| ElastiCache | Redis r6g.large cluster | $200 |
| Secrets Manager | 10 secrets | $10 |
| CloudWatch | Advanced monitoring & logs | $80 |
| WAF | Enhanced rule sets | $20 |
| **Total** | | **~$2,740/month** |

### 100,000 Users - Large Enterprise

**Monthly AWS Costs:**

| Service | Configuration | Monthly Cost |
|---------|--------------|--------------|
| RDS Aurora | PostgreSQL cluster, 3 instances | $1,200 |
| RDS Read Replicas | 5x r6g.xlarge global replicas | $2,000 |
| ECS Fargate | 40-100 tasks (20-50 per service), multiple clusters | $3,600 |
| ALB | Multiple ALBs, cross-region | $150 |
| NAT Gateway | Enterprise data transfer | $300 |
| CloudFront | ~10TB transfer, enterprise CDN | $500 |
| EFS Storage | ~10TB, provisioned throughput | $600 |
| ElastiCache | Redis cluster, multiple AZs | $800 |
| Route 53 | DNS management, health checks | $50 |
| Secrets Manager | 25 secrets | $25 |
| CloudWatch | Enterprise monitoring suite | $300 |
| WAF | Advanced protection | $100 |
| Config & CloudTrail | Compliance logging | $150 |
| **Total** | | **~$7,775/month** |

### 1,000,000 Users - Global Scale

**Monthly AWS Costs:**

| Service | Configuration | Monthly Cost |
|---------|--------------|--------------|
| RDS Aurora Global | Multi-region cluster | $5,000 |
| EKS Clusters | Multiple regions, managed nodes | $8,000 |
| ALB/NLB | Global load balancing | $500 |
| Transit Gateway | Multi-region networking | $400 |
| CloudFront | ~100TB transfer, enterprise | $2,000 |
| EFS Storage | ~100TB, multi-region replication | $4,000 |
| ElastiCache Global | Redis clusters, multiple regions | $3,000 |
| Route 53 | Global DNS, traffic management | $200 |
| Secrets Manager | Enterprise secret management | $100 |
| CloudWatch | Global monitoring & analytics | $1,500 |
| WAF | Advanced threat protection | $500 |
| Shield Advanced | DDoS protection | $3,000 |
| Config & CloudTrail | Global compliance | $800 |
| Data Transfer | Inter-region & internet | $2,000 |
| **Total** | | **~$31,800/month** |

### 100,000,000+ Users - Internet Scale

**Monthly AWS Costs:**

| Service | Configuration | Monthly Cost |
|---------|--------------|--------------|
| Multi-Cloud Setup | AWS + other cloud providers | $50,000+ |
| Global Database | Distributed across continents | $25,000+ |
| Container Orchestration | EKS + self-managed K8s | $40,000+ |
| CDN & Edge Computing | Global edge network | $15,000+ |
| Advanced Security | Multi-layered protection | $10,000+ |
| Monitoring & Analytics | Real-time global insights | $8,000+ |
| Data Storage | Petabyte-scale distributed | $20,000+ |
| **Total** | | **~$168,000+/month** |

## Scaling Triggers and Thresholds

### Automatic Scaling Triggers

**CPU-Based Scaling (per service):**

- Scale out: >70% CPU for 5 minutes
- Scale in: <30% CPU for 10 minutes
- Cooldown: 5 minutes between scaling events

**Memory-Based Scaling (per service):**

- Scale out: >80% memory for 5 minutes
- Scale in: <40% memory for 10 minutes

**Request-Based Scaling:**

- Frontend: >500 requests/minute per task
- Backend: >1000 API calls/minute per task
- Scale in: <100 requests/minute per task

**Database Scaling:**

- CPU >75% for 15 minutes: Consider read replica
- Connections >80% of max: Scale up instance class
- Storage >85% full: Increase allocated storage
- Query time >500ms p95: Optimize Prisma queries
- Connection pool exhaustion: Increase pool size

### Manual Scaling Considerations

**Planned Traffic Increases:**

- Pre-scale both services before marketing campaigns
- Schedule scaling for known traffic patterns
- Load test new configurations
- Warm up OAuth token cache
- Pre-generate database connection pools

**Geographic Expansion:**

- Add CloudFront edge locations
- Consider additional AWS regions
- Implement cross-region replication

## Cost Optimization Strategies

### By User Tier

**10-100 Users:**

- Use AWS Free Tier where possible
- Single-AZ RDS for development/testing
- Reserved Instances for predictable workloads
- Implement automated start/stop for non-production
- Share EFS between frontend/backend services

**100-1,000 Users:**

- Purchase RDS Reserved Instances
- Use Spot Instances for development environments
- Implement EFS Lifecycle policies
- Optimize CloudFront caching
- Enable Prisma query caching

**1,000-10,000 Users:**

- Savings Plans for compute resources
- Database performance optimization with read replicas
- Advanced caching strategies (Redis, in-memory)
- Regular cost analysis and right-sizing
- Implement API response caching

**10,000+ Users:**

- Enterprise Discount Program (EDP)
- Dedicated instances for consistent performance
- Advanced monitoring for cost optimization
- Regular architecture reviews

### Monitoring and Cost Controls

**Budget Alerts by Scale:**

- 10-100 users: $200/month budget
- 100-1,000 users: $600/month budget  
- 1,000-10,000 users: $2,500/month budget
- 10,000+ users: Custom enterprise budgets

**Cost Optimization Tools:**

- AWS Cost Explorer for trend analysis
- AWS Trusted Advisor for recommendations
- Third-party tools (CloudHealth, CloudCheckr)
- Regular cost review meetings

## Performance Benchmarks

### Expected Performance by Scale

| User Count | Frontend Load Time | API Response Time | Concurrent Users | Database Queries/sec |
|------------|-------------------|-------------------|------------------|---------------------|
| 10 | <1 second | <100ms | 5-10 | 10-20 |
| 100 | <1 second | <150ms | 20-50 | 50-100 |
| 1,000 | <2 seconds | <200ms | 100-200 | 200-500 |
| 10,000 | <2 seconds | <300ms | 500-1,000 | 1,000-2,000 |
| 100,000 | <3 seconds | <400ms | 2,000-5,000 | 5,000-10,000 |
| 1,000,000+ | <4 seconds | <500ms | 10,000+ | 20,000+ |

### Bottleneck Identification

**Database Bottlenecks:**

- Prisma connection pool exhaustion
- Query execution time (N+1 queries)
- Storage I/O limitations
- Memory constraints
- Transaction deadlocks

**Application Bottlenecks:**

- ECS task resource limits per service
- Memory leaks in Node.js applications
- Inefficient caching strategies
- OAuth session storage limitations
- API rate limiting bottlenecks

**Network Bottlenecks:**

- ALB request limits
- CloudFront cache miss rates
- Inter-AZ data transfer costs
- DNS resolution delays

## Deployment Strategies for Scale

### Blue-Green Deployments

- Zero-downtime deployments for both services
- Quick rollback capabilities
- Suitable for 1,000+ users
- Separate deployment for frontend/backend

### Canary Deployments  

- Gradual traffic shifting per service
- Risk mitigation for large changes
- Recommended for 10,000+ users
- A/B testing for frontend features

### Multi-Region Deployments

- Disaster recovery capabilities
- Global performance optimization
- Required for 100,000+ users

### Microservices Architecture

- Further service decomposition strategy
- Independent scaling capabilities  
- Consider at 100,000+ user scale
- GraphQL federation for API gateway

This scaling guide should be reviewed quarterly and updated based on actual usage patterns, AWS service improvements, and framework updates for Next.js, Hono, and Prisma.
