# 🚨 Database Connection Issues - Fixes Applied

## Issues Identified

From your logs:

```
Can't reach database server at `ep-tiny-math-a2zsshve-pooler.eu-central-1.aws.neon.tech:5432`
[NODE-CRON] [WARN] missed execution! Possible blocking IO or high CPU
```

## Root Causes

1. **Multiple PrismaClient instances** across schedulers
2. **No connection retry logic** for temporary failures
3. **No connection pooling optimization** for Neon
4. **Aggressive scheduler intervals** overwhelming database

## Fixes Applied ✅

### 1. Connection Retry Logic (`lib/database-retry.ts`)

- **Automatic retry** for connection errors
- **Exponential backoff** (1s → 2s → 4s → 10s max)
- **Smart error detection** (only retry connection issues)
- **Configurable retry attempts** (default: 3 retries)

### 2. Enhanced Schedulers

- **Import Processor**: Added retry wrapper around main processing
- **Session Processor**: Added retry wrapper around AI processing
- **Graceful degradation** when database is temporarily unavailable

### 3. Singleton Pattern Enforced

- **All schedulers now use** `import { prisma } from "./prisma.js"`
- **No more separate** `new PrismaClient()` instances
- **Shared connection pool** across all operations

### 4. Neon-Specific Optimizations

- **Connection limit guidance**: 15 connections (below Neon's 20 limit)
- **Extended timeouts**: 30s for cold start handling
- **SSL mode requirements**: `sslmode=require` for Neon
- **Application naming**: For better monitoring

## Immediate Actions Needed

### 1. Update Environment Variables

```bash
# Add to .env.local
USE_ENHANCED_POOLING=true
DATABASE_CONNECTION_LIMIT=15
DATABASE_POOL_TIMEOUT=30

# Update your DATABASE_URL to include:
DATABASE_URL="postgresql://user:pass@ep-tiny-math-a2zsshve-pooler.eu-central-1.aws.neon.tech:5432/db?sslmode=require&connection_limit=15&pool_timeout=30"
```

### 2. Reduce Scheduler Frequency (Optional)

```bash
# Less aggressive intervals
CSV_IMPORT_INTERVAL="*/30 * * * *"        # Every 30 min (was 15)
IMPORT_PROCESSING_INTERVAL="*/10 * * * *"  # Every 10 min (was 5)
SESSION_PROCESSING_INTERVAL="0 */2 * * *"  # Every 2 hours (was 1)
```

### 3. Run Configuration Check

```bash
pnpm db:check
```

## Expected Results

✅ **Connection Stability**: Automatic retry on temporary failures  
✅ **Resource Efficiency**: Single shared connection pool  
✅ **Neon Optimization**: Proper connection limits and timeouts  
✅ **Monitoring**: Health check endpoint for visibility  
✅ **Graceful Degradation**: Schedulers won't crash on DB issues

## Monitoring

- **Health Endpoint**: `/api/admin/database-health`
- **Connection Logs**: Enhanced logging for pool events
- **Retry Logs**: Detailed retry attempt logging
- **Error Classification**: Retryable vs non-retryable errors

## Files Modified

- `lib/database-retry.ts` - New retry utilities
- `lib/importProcessor.ts` - Added retry wrapper
- `lib/processingScheduler.ts` - Added retry wrapper
- `docs/neon-database-optimization.md` - Neon-specific guide
- `scripts/check-database-config.ts` - Configuration checker

The connection issues should be significantly reduced with these fixes! 🎯