# didiQueue - RabbitMQ Message Queue Service 🐰

## Overview
RabbitMQ message broker for asynchronous communication between the Orchestrator and Analysis Service in the DIDI Backend platform.

## 🎯 Purpose
Provides reliable message queuing for pipeline execution jobs, decoupling the API layer from the processing layer.

## 🚀 Quick Start

### Start the Service
```bash
# From this directory
docker compose up -d

# Or from data-layer directory
make up-queue
```

### Access Points
- **AMQP Protocol**: `localhost:5672`
- **Management UI**: `http://localhost:15672`
- **Default Credentials**: `admin / rabbitmq123`

## 📊 Queue Architecture

Since we're merging all analysis services into one unified service, we use a **single queue**:

```
Orchestrator → publishes → analysis_queue → consumed by → Analysis Service
```

### Queue Configuration
- **Queue Name**: `analysis_queue`
- **Type**: Durable (survives restarts)
- **Dead Letter Queue**: `analysis_dlq` (for failed messages)
- **Message TTL**: 24 hours
- **Auto-delete**: No

## 🔧 Configuration

### Environment Variables
Edit `.env` file to customize:
```env
RABBITMQ_USER=admin
RABBITMQ_PASSWORD=rabbitmq123  # CHANGE IN PRODUCTION!
RABBITMQ_VHOST=/
RABBITMQ_PORT=5672
RABBITMQ_MGMT_PORT=15672
```

### Resource Limits
```yaml
Memory: 1GB (max) / 512MB (reserved)
CPU: 0.5 cores (max) / 0.25 cores (reserved)
```

## 📝 Message Format

Messages published to the queue follow this structure:
```json
{
  "run_id": "analysis_abc123_20250901_120000",
  "pipeline_id": "uuid-here",
  "pipeline_version": 1,
  "input_data": {
    "text": "Content to analyze",
    "image": "base64_or_url",
    "audio": "url_to_audio",
    "video": "url_to_video"
  },
  "media_type": "text|image|audio|video",
  "created_at": "2025-09-01T12:00:00Z"
}
```

## 🔍 Management

### View Queue Status
```bash
# Using Management UI
http://localhost:15672

# Using CLI
docker exec didi-queue rabbitmqctl list_queues

# Check queue depth
docker exec didi-queue rabbitmqctl list_queues name messages_ready messages_unacknowledged
```

### Purge Queue (Development Only)
```bash
# Remove all messages from queue
docker exec didi-queue rabbitmqctl purge_queue analysis_queue
```

### Health Check
```bash
# Check if RabbitMQ is responsive
docker exec didi-queue rabbitmq-diagnostics -q ping

# Detailed health check
docker exec didi-queue rabbitmq-diagnostics check_running
```

## 🏗️ Integration Points

### Publishers (Orchestrator)
```python
import aio_pika

# Connect
connection = await aio_pika.connect_robust(
    "amqp://admin:rabbitmq123@localhost:5672/"
)
channel = await connection.channel()

# Publish message
await channel.default_exchange.publish(
    aio_pika.Message(body=json.dumps(message).encode()),
    routing_key="analysis_queue"
)
```

### Consumers (Analysis Service)
```python
# Declare queue
queue = await channel.declare_queue("analysis_queue", durable=True)

# Consume messages
async for message in queue:
    async with message.process():
        body = json.loads(message.body.decode())
        # Process the message
```

## 🛠️ Troubleshooting

### Queue is not created
The `init-queues.sh` script runs automatically on container start. Check logs:
```bash
docker logs didi-queue
```

### Messages not being consumed
1. Check if Analysis Service is running
2. Verify queue has messages: `docker exec didi-queue rabbitmqctl list_queues`
3. Check for dead letter queue: `docker exec didi-queue rabbitmqctl list_queues | grep dlq`

### High memory usage
```bash
# Check memory usage
docker exec didi-queue rabbitmq-diagnostics memory_breakdown

# Set memory limit
docker exec didi-queue rabbitmqctl set_vm_memory_high_watermark 0.4
```

## 🔐 Security

### Production Checklist
- [ ] Change default password in `.env`
- [ ] Enable SSL/TLS for connections
- [ ] Restrict management UI access
- [ ] Set up user permissions
- [ ] Configure firewall rules
- [ ] Enable audit logging

### Create Production User
```bash
# Create new user
docker exec didi-queue rabbitmqctl add_user analysis_service SECURE_PASSWORD

# Set permissions
docker exec didi-queue rabbitmqctl set_permissions -p / analysis_service ".*" ".*" ".*"

# Set user tags
docker exec didi-queue rabbitmqctl set_user_tags analysis_service monitoring
```

## 📊 Monitoring

### Key Metrics
- Queue depth (messages waiting)
- Message rates (publish/consume)
- Connection count
- Memory usage
- Disk usage

### Prometheus Metrics
RabbitMQ exposes metrics at: `http://localhost:15692/metrics`

## 🔄 Backup & Recovery

### Backup
```bash
# Export definitions
docker exec didi-queue rabbitmqctl export_definitions /var/lib/rabbitmq/backup.json
docker cp didi-queue:/var/lib/rabbitmq/backup.json ./backup.json
```

### Restore
```bash
# Import definitions
docker cp ./backup.json didi-queue:/var/lib/rabbitmq/backup.json
docker exec didi-queue rabbitmqctl import_definitions /var/lib/rabbitmq/backup.json
```

## 📚 Related Documentation
- [Data Layer README](../README.md)
- [RabbitMQ Documentation](https://www.rabbitmq.com/documentation.html)
- [AMQP Protocol](https://www.amqp.org/)

---
*Part of the DIDI Backend Data Layer*