# DIDI Cache Service 🚀

## Super Simple Start Guide ⚡

### Step 1: Set Your Password
```bash
# Copy the example file
cp .env.example .env

# Edit .env and change this line:
REDIS_PASSWORD=YOUR_SECURE_PASSWORD_HERE
```

### Step 2: Start Redis
```bash
docker compose up -d
```

That's it! Your cache is running! 🎉

## Check If It's Working ✅

```bash
# See if container is healthy
docker ps

# Look for: didi-cache (healthy)
```

## Connection Info 📡

- **Host**: localhost
- **Port**: 6380 (not 6379 to avoid conflicts!)
- **Password**: (what you set in .env)

## Test the Connection 🔌

```bash
# Connect with Redis CLI
docker exec -it didi-cache redis-cli -a YOUR_PASSWORD

# Test it
127.0.0.1:6379> PING
PONG

# Exit
127.0.0.1:6379> EXIT
```

## What's Inside? 📦

This Redis cache is configured for:
- ✅ 512MB memory (perfect for status & results)
- ✅ Auto-expiry support (services set TTL)
- ✅ Persistence enabled (survives restarts)
- ✅ Password protected

### How DIDI Uses Redis 🔄

```
Pipeline runs → Status stored here (24hr TTL)
              → Results cached here
              → UI polls for updates
              → After 24hrs, auto-deleted
```

### Key Patterns We Store 📝
- `run:{run_id}` - Pipeline execution status
- `node_status:{run_id}` - Each node's progress
- `results:{run_id}` - Analysis results

## Common Commands 🛠️

```bash
# Stop cache
docker compose down

# View logs
docker compose logs -f

# Connect to Redis CLI
docker exec -it didi-cache redis-cli -a YOUR_PASSWORD

# Restart fresh (WARNING: Deletes all cache!)
docker compose down -v
docker compose up -d
```

## Monitor Cache Usage 📊

```bash
# Check memory usage
docker exec -it didi-cache redis-cli -a YOUR_PASSWORD INFO memory

# See all keys
docker exec -it didi-cache redis-cli -a YOUR_PASSWORD KEYS "*"

# Count keys
docker exec -it didi-cache redis-cli -a YOUR_PASSWORD DBSIZE
```

## Troubleshooting 🔧

### Port 6380 already in use?
Edit `.env` and change `REDIS_PORT` to something else (like 6381)

### Can't connect?
1. Check container is healthy: `docker ps`
2. Verify password in .env
3. Make sure you're using port 6380, not 6379

### Memory full?
Redis will auto-delete least recently used keys (LRU policy)

## Part of Something Bigger 🏗️

This cache is part of the DIDI Backend data layer:

```
📁 data-layer/
  ├── 📁 didiDatabase/  (PostgreSQL - Done!)
  ├── 📁 didiCache/     (Redis - You are here!)
  ├── 📁 didiQueue/     (RabbitMQ - Next)
  └── 📁 didiStorage/   (MinIO - Coming soon)
```

## Quick Health Check 🏥

```bash
# Is it running?
docker exec -it didi-cache redis-cli -a YOUR_PASSWORD PING

# Response should be:
# PONG
```

## Why Port 6380? 🤔

The old monolithic setup uses port 6379. We use 6380 to:
- Avoid conflicts during migration
- Run both services side-by-side
- Easy rollback if needed

---
**That's all you need to know! Happy caching! ⚡**

*Version: 1.0.0 | Redis 7-alpine*