# Parallel Deployment Strategy

## Overview

This deployment strategy optimizes for **full parallel execution** across all 24 regions, maximizing deployment speed while excluding West Europe from validator deployment (admin use only).

## Key Optimizations

### 1. Parallel Terraform Execution
- **Terraform Parallelism**: Set to 50 (allows concurrent resource creation)
- **Region Independence**: Each region deploys independently
- **No Dependencies**: Regions don't depend on each other

### 2. Parallel Kubernetes Configuration
- **xargs -P 24**: Configure all 24 regions simultaneously
- **Independent Operations**: Each region configured separately
- **No Blocking**: One region's failure doesn't block others

### 3. Parallel Besu Deployment
- **Concurrent Deployments**: Deploy validators to all regions at once
- **Independent State**: Each region's Besu network is independent
- **Fast Startup**: All validators start simultaneously

## Region Strategy

### Deployment Regions (24)
All regions have 10+ vCPUs available:
1. North Europe
2. UK South
3. UK West
4. France Central
5. Germany West Central
6. Switzerland North
7. Italy North
8. Norway East
9. Poland Central
10. Spain Central
11. Sweden Central
12. Belgium Central
13. Australia East
14. Australia Southeast
15. East Asia
16. Southeast Asia
17. Central India
18. South India
19. West India (replacement for West Europe)
20. Japan East
21. Japan West
22. Korea Central
23. Korea South
24. Canada Central

**Total**: 24 regions × 10 vCPUs = 240 vCPUs ✅

### Administrative Region (West Europe)
- **Purpose**: Monitoring, management, control plane only
- **No Validators**: West Europe does not host validators
- **No Sentries**: West Europe does not host sentries
- **Optional System Nodes**: For admin tools only
- **Quota**: Not counted in 240 vCPU deployment

## Deployment Phases (Parallel)

### Phase 1: Infrastructure (Parallel)
```bash
cd terraform/well-architected/cloud-sovereignty
terraform init
terraform plan -out=tfplan-parallel -parallelism=50
terraform apply -parallelism=50 tfplan-parallel
```
- **Time**: 30-60 minutes (vs 2-4 hours sequential)
- **Speed**: 4-8x faster than sequential

### Phase 2: Kubernetes Configuration (Parallel)
```bash
./scripts/deployment/configure-kubernetes-parallel.sh
```
- **Time**: 5-10 minutes (vs 1-2 hours sequential)
- **Speed**: 12-24x faster than sequential

### Phase 3: Besu Network (Parallel)
```bash
./scripts/deployment/deploy-besu-parallel.sh
```
- **Time**: 10-15 minutes (vs 2-3 hours sequential)
- **Speed**: 12-18x faster than sequential

### Phase 4: Contracts (Can be parallel)
- Deploy Mainnet contracts
- Deploy Chain-138 contracts
- Can run in parallel if using different networks

### Phase 5: CCIP Integration (Sequential)
- Configure routers (sequential due to dependencies)
- Fund contracts (sequential for safety)

## Performance Comparison

| Phase | Sequential | Parallel | Speedup |
|-------|-----------|----------|---------|
| Infrastructure | 2-4 hours | 30-60 min | 4-8x |
| Kubernetes | 1-2 hours | 5-10 min | 12-24x |
| Besu Network | 2-3 hours | 10-15 min | 12-18x |
| **Total** | **5-9 hours** | **45-85 min** | **6-12x** |

## Parallel Execution Scripts

### Master Script
```bash
./scripts/deployment/deploy-parallel.sh
```
- Deploys all infrastructure in parallel
- Uses Terraform parallelism=50

### Kubernetes Configuration
```bash
./scripts/deployment/configure-kubernetes-parallel.sh
```
- Configures all 24 regions simultaneously
- Uses xargs -P 24

### Besu Deployment
```bash
./scripts/deployment/deploy-besu-parallel.sh
```
- Deploys Besu to all regions simultaneously
- Uses xargs -P 24

### Verification
```bash
./scripts/deployment/verify-all-clusters-parallel.sh
```
- Verifies all clusters in parallel
- Uses xargs -P 24

## Benefits

1. **Speed**: 6-12x faster deployment
2. **Efficiency**: All regions deploy simultaneously
3. **Scalability**: Easy to add more regions
4. **Resilience**: One region's failure doesn't block others
5. **Resource Utilization**: Maximum use of available resources

## Considerations

### Resource Limits
- **Azure API Rate Limits**: May need to throttle if hitting limits
- **Terraform State**: Concurrent writes to state file (Terraform handles this)
- **Network Bandwidth**: High bandwidth usage during parallel deployment

### Error Handling
- **Partial Failures**: Some regions may fail, others succeed
- **Retry Logic**: Failed regions can be retried independently
- **Verification**: Always verify all regions after deployment

### Monitoring
- **Progress Tracking**: Monitor deployment progress per region
- **Error Detection**: Detect and report failures quickly
- **Resource Usage**: Monitor quota and API usage

## West Europe Administrative Setup

### Resources in West Europe
- **Monitoring Stack**: Prometheus, Grafana (centralized)
- **Management Tools**: Control plane, admin dashboards
- **Log Aggregation**: Centralized logging from all regions
- **Backup Storage**: Centralized backup storage

### Configuration
```bash
# Deploy admin resources to West Europe only
cd terraform/well-architected/cloud-sovereignty
terraform apply -target=module.region_deployment["westeurope"] \
  -var="deploy_aks_clusters=false" \
  -var="validator_count=0" \
  -var="sentry_count=0"
```

## Next Steps

1. ✅ Configuration updated (24 regions, excluding West Europe)
2. ⏳ Run parallel deployment: `./scripts/deployment/deploy-parallel.sh`
3. ⏳ Verify all clusters: `./scripts/deployment/verify-all-clusters-parallel.sh`
4. ⏳ Configure Kubernetes: `./scripts/deployment/configure-kubernetes-parallel.sh`
5. ⏳ Deploy Besu: `./scripts/deployment/deploy-besu-parallel.sh`
