# Load Testing Cheat Sheet

## Prerequisites Check
```bash
# Docker services running?
docker ps | grep -E "(redis|postgres)" | wc -l  # Should be 2+

# API Gateway running?
curl -f http://localhost:50050/health && echo "✅ Ready" || echo "❌ Not running"

# Load tests built?
ls -lah ../../target/release/load_test_runner && echo "✅ Built" || echo "❌ Not built"
```

## Quick Commands

### Run Tests
```bash
# Normal Load (1K clients, 60s)
cargo run -r --bin load_test_runner -- normal

# Spike Load (0→10K clients)
cargo run -r --bin load_test_runner -- spike

# Stress Test (find breaking point)
cargo run -r --bin load_test_runner -- stress

# All tests
cargo run -r --bin load_test_runner -- all
```

### View Results
```bash
firefox *.html  # Open all reports
```

### Extract Metrics
```bash
# P99 Latency
grep -oP 'P99 Latency.*?value">\K[^<]+' normal_load_report.html

# Throughput
grep -oP 'Requests/Second.*?value">\K[^<]+' normal_load_report.html

# Error Rate
grep -oP 'Error Rate.*?value">\K[^<]+' normal_load_report.html
```

## Performance Targets

| Metric | Target | Pass/Fail |
|--------|--------|-----------|
| P99 Latency | <10μs | ✅ / ❌ |
| Throughput | >100K req/s | ✅ / ❌ |
| Error Rate | <0.1% | ✅ / ❌ |

## Troubleshooting

### Connection Refused
```bash
# Start API Gateway
cargo run -r -p api_gateway
```

### High Latency
```bash
# Check CPU
top -p $(pgrep api_gateway)

# Check DB connections
psql -h localhost -p 5433 -U postgres -c 'SELECT count(*) FROM pg_stat_activity;'
```

### High Errors
```bash
# Check logs
docker logs foxhunt-api-gateway --tail 50

# Check backend health
curl http://localhost:50051/health  # Trading
curl http://localhost:50052/health  # Backtesting
curl http://localhost:50053/health  # ML Training
```

## 5-Minute Validation

```bash
# 1. Start services
docker-compose up -d redis postgres

# 2. Start API Gateway
cargo run -r -p api_gateway &

# 3. Wait for startup
sleep 5

# 4. Run quick test
cd services/api_gateway/load_tests
cargo run -r --bin load_test_runner -- normal --num-clients 100 --duration-secs 30

# 5. Check results
firefox normal_load_report.html
```

## Expected Results

### Good Performance ✅
```
Requests/Second:  >100,000
Error Rate:       <0.1%
P99 Latency:      <10μs
```

### Needs Work ⚠️
```
Requests/Second:  1,000-10,000
Error Rate:       0.5%-5%
P99 Latency:      10-100ms
```

## Files Generated

```
normal_load_report.html         # Main dashboard
normal_load_report.rps.svg      # RPS chart
normal_load_report.latency.svg  # Latency chart
normal_load_report.errors.svg   # Error chart
```

## Custom Parameters

```bash
# Custom normal load
cargo run -r --bin load_test_runner -- normal \
    --num-clients 500 \
    --duration-secs 120

# Custom spike load
cargo run -r --bin load_test_runner -- spike \
    --target-clients 5000 \
    --ramp-up-secs 15

# Custom stress test
cargo run -r --bin load_test_runner -- stress \
    --initial-clients 200 \
    --increment 200 \
    --max-p99-latency-ms 100.0
```

## Monitoring Commands

```bash
# Real-time metrics
watch -n 1 "curl -s http://localhost:50050/metrics | grep requests_total"

# Docker stats
watch -n 1 "docker stats --no-stream foxhunt-api-gateway"

# System resources
watch -n 1 "ps aux | grep api_gateway | grep -v grep"
```