---
title: "Scalability"
description: "Scaling strategies for TraceRTM"
keywords: [scalability, scaling, horizontal, vertical, performance]
---

# Scalability

Scaling strategies for handling growth in TraceRTM.

## Scaling Dimensions

### 1. Horizontal Scaling

Add more servers:

```yaml
# Kubernetes deployment
replicas: 3  # Scale to 3 instances
```

**Benefits:**
- No downtime
- Better fault tolerance
- Cost-effective

**Considerations:**
- Stateless services required
- Load balancing needed
- Shared state management

### 2. Vertical Scaling

Increase server resources:

```yaml
resources:
  requests:
    memory: "2Gi"
    cpu: "2000m"
  limits:
    memory: "4Gi"  # Increase
    cpu: "4000m"   # Increase
```

**Benefits:**
- Simple to implement
- No code changes

**Limitations:**
- Hardware limits
- Single point of failure

## Scaling Strategies

### Database Scaling

#### Read Replicas

```python
# Route reads to replicas
read_db = create_engine(READ_REPLICA_URL)
write_db = create_engine(WRITE_DB_URL)
```

#### Sharding

```python
# Partition data by project_id
shard = get_shard(project_id)
db = get_db_for_shard(shard)
```

### Caching

```python
# Cache frequently accessed data
redis_client = redis.from_url(REDIS_URL)

async def get_item_cached(item_id: str):
    cached = await redis_client.get(f"item:{item_id}")
    if cached:
        return json.loads(cached)
    # ... fetch from database
```

### Load Balancing

```yaml
# Kubernetes service with load balancer
apiVersion: v1
kind: Service
spec:
  type: LoadBalancer
  ports:
  - port: 80
    targetPort: 8000
```

## Auto-Scaling

### Horizontal Pod Autoscaler

```yaml
apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
spec:
  minReplicas: 3
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        averageUtilization: 70
```

## Scaling Checklist

- [ ] Stateless services
- [ ] Database connection pooling
- [ ] Caching layer
- [ ] Load balancing
- [ ] Monitoring and alerts
- [ ] Auto-scaling configured

## Related Documentation

- [Performance](./06-performance) - Performance optimization
- [Horizontal Scaling](../../05-deployment/06a-horizontal-scaling) - Horizontal scaling guide
