# World-Class Load Testing Script - Complete Guide

## 📖 Table of Contents
1. [What is This?](#what-is-this)
2. [Prerequisites](#prerequisites)
3. [Quick Start](#quick-start)
4. [Understanding the Flow](#understanding-the-flow)
5. [Command Line Arguments](#command-line-arguments)
6. [Multi-Device Execution](#multi-device-execution)
7. [Understanding Results](#understanding-results)
8. [Troubleshooting](#troubleshooting)
9. [Best Practices](#best-practices)
10. [Advanced Usage](#advanced-usage)

---

## 🎯 What is This?

This is a **world-class load testing script** that simulates multiple students completing the full assessment flow simultaneously. It's designed to:

- ✅ Test backend/server performance under load
- ✅ Verify system stability with concurrent users
- ✅ Provide transparent, real-time metrics
- ✅ Support multi-device execution (distributed load testing)
- ✅ Use only 100% verified, reliable automation flows

### What Each Student Does

**Complete Flow (9 Steps):**
1. **Login** → Excel password first, fallback to Admin@123
2. **Password Reset** → If modal appears (smart detection)
3. **Profile Fill** → Complete to 100% if incomplete (smart detection)
4. **Navigate to Assessments** → Go to assessments page
5. **Start Assessment** → Click first available assessment
6. **Select Domain** → Click first unlocked domain
7. **Answer All Questions** → Answer all questions in domain (handles all 5 question types)
8. **Submit Assessment** → Submit when all questions answered
9. **Feedback** → Submit domain feedback if modal appears

**Total Time:** ~3-5 minutes per student (depending on number of questions)

---

## 📋 Prerequisites

### Required
- ✅ Python 3.8+
- ✅ Virtual environment activated
- ✅ Chrome browser installed
- ✅ ChromeDriver installed
- ✅ CSV file with student data
- ✅ Backend server running (localhost:3983 for local)

### CSV File Format

Your CSV file must have these columns (case-insensitive):
- `Student CPID` or `student_cpid` or `cpid` or `CPID` (required)
- `Password` or `password` or `PASSWORD` (optional, will use Admin@123 if missing)
- `First Name` (optional, for display)
- `Last Name` (optional, for display)

**Example CSV:**
```csv
Student CPID,Password,First Name,Last Name
STU001,Pass123,John,Doe
STU002,Pass456,Jane,Smith
```

---

## 🚀 Quick Start

### Step 1: Activate Virtual Environment
```bash
cd /home/tech4biz/work/CP_Front_Automation_Test
source venv/bin/activate
```

### Step 2: Validate Function Signature (Recommended)
```bash
python3 tests/load_tests/validate_function_signature.py
```
**Expected Output:** ✅ Function signature is valid!

### Step 3: Run Your First Test (1 Student)
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students_with_passwords_2025-12-12T13-19-32.csv \
    --start 0 \
    --end 1 \
    --workers 1 \
    --headless \
    --metrics-interval 1
```

### Step 4: Scale Up (10 Students)
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students_with_passwords_2025-12-12T13-19-32.csv \
    --start 0 \
    --end 10 \
    --workers 10 \
    --headless \
    --metrics-interval 5
```

### Step 5: Full Load Test (100 Students)
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students_with_passwords_2025-12-12T13-19-32.csv \
    --start 0 \
    --end 100 \
    --workers 100 \
    --headless \
    --metrics-interval 10
```

---

## 🔍 Understanding the Flow

### What Happens Behind the Scenes

1. **Script starts** → Loads students from CSV (with range filter)
2. **For each student** (in parallel):
   - Creates Chrome browser (headless or visible)
   - Logs in (smart password handling)
   - Handles password reset if needed
   - Completes profile if needed
   - Navigates to assessments
   - Starts first assessment
   - Selects first domain
   - Answers ALL questions
   - Submits assessment
   - Handles feedback
   - Closes browser
3. **Metrics collected** → Real-time performance tracking
4. **Results saved** → JSON report generated

### Smart Features

- **Smart Login**: Tries Excel password first, falls back to Admin@123
- **Smart Password Reset**: Only resets if needed (checks current password state)
- **Smart Profile Completion**: Only completes if profile is incomplete
- **Smart Question Answering**: Handles all 5 question types automatically
- **Smart Error Recovery**: Retries on transient failures

---

## ⚙️ Command Line Arguments

### Required Arguments

| Argument | Description | Example |
|----------|-------------|---------|
| `--csv` | Path to CSV file | `students_with_passwords_2025-12-12T13-19-32.csv` |

### Optional Arguments

| Argument | Description | Default | Example |
|----------|-------------|---------|---------|
| `--start` | Start index (0-based, excluding header) | `0` | `0`, `100`, `200` |
| `--end` | End index (exclusive, None = all remaining) | `None` | `100`, `200`, `500` |
| `--workers` | Max concurrent workers | All students | `10`, `50`, `100` |
| `--headless` | Run in headless mode | `True` | (flag) |
| `--visible` | Run in visible mode (overrides headless) | `False` | (flag) |
| `--metrics-interval` | Print metrics every N students | `10` | `5`, `10`, `20` |

### Examples

**Basic usage:**
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students.csv \
    --start 0 \
    --end 100
```

**With all options:**
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students.csv \
    --start 0 \
    --end 100 \
    --workers 50 \
    --headless \
    --metrics-interval 10
```

**Visible mode (for debugging):**
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students.csv \
    --start 0 \
    --end 5 \
    --workers 5 \
    --visible
```

---

## 🌐 Multi-Device Execution

This script supports **distributed load testing** across multiple devices. Each device runs a different range of students.

### Example: 500 Students on 5 Devices

**Device 1** (Students 0-99):
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students_with_passwords_2025-12-12T13-19-32.csv \
    --start 0 \
    --end 100 \
    --workers 100 \
    --headless
```

**Device 2** (Students 100-199):
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students_with_passwords_2025-12-12T13-19-32.csv \
    --start 100 \
    --end 200 \
    --workers 100 \
    --headless
```

**Device 3** (Students 200-299):
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students_with_passwords_2025-12-12T13-19-32.csv \
    --start 200 \
    --end 300 \
    --workers 100 \
    --headless
```

**Device 4** (Students 300-399):
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students_with_passwords_2025-12-12T13-19-32.csv \
    --start 300 \
    --end 400 \
    --workers 100 \
    --headless
```

**Device 5** (Students 400-500):
```bash
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students_with_passwords_2025-12-12T13-19-32.csv \
    --start 400 \
    --end 500 \
    --workers 100 \
    --headless
```

### Range Calculation

- `--start 0 --end 100` = Students at indices 0-99 (100 students)
- `--start 100 --end 200` = Students at indices 100-199 (100 students)
- `--start 0 --end 500` = Students at indices 0-499 (500 students)

**Note:** Index 0 is the first student (after header row in CSV)

---

## 📊 Understanding Results

### Real-Time Metrics

During execution, you'll see metrics printed every N students:

```
📊 REAL-TIME METRICS
================================================================================
⏱️  Elapsed Time:        125.3s
✅ Completed:            50
❌ Failed:               2
📈 Success Rate:         96.2%
⚡ Rate:                 0.40 students/sec
⏳ Avg Duration:         245.6s
❓ Avg Questions:         12.3
📊 Total Questions:      615

📋 STEP METRICS:
   login                : 100.0% success, 2.1s avg
   password_reset       :  95.0% success, 3.5s avg
   profile_completion   :  90.0% success, 15.2s avg
   assessment           :  96.0% success, 220.5s avg
================================================================================
```

### Final Summary

After completion, you'll see:

```
================================================================================
LOAD TEST SUMMARY: Complete Assessment Flow
================================================================================

📊 OVERALL METRICS
  Total Users:           100
  Successful:           95 (95.00%)
  Failed:               5
  Skipped:               0
  Total Duration:        1250.5 seconds

⏱️  PERFORMANCE METRICS
  Average Duration:      245.6 seconds
  Min Duration:          180.2 seconds
  Max Duration:          320.5 seconds
  Median (P50):          240.1 seconds
  95th Percentile (P95): 310.2 seconds
  99th Percentile (P99): 318.5 seconds

📄 PAGE METRICS
  Avg Page Load Time:    2.3 seconds
  Avg Scroll Time:       0.5 seconds
  Scroll Smooth Rate:    98.0%
```

### JSON Report

Results are saved to:
```
reports/load_tests/load_test_Complete_Assessment_Flow_{N}users_{timestamp}.json
```

**Report contains:**
- Summary metrics (success rate, durations, percentiles)
- Individual student results
- Step-by-step completion status
- Error details (if any)
- Page load metrics

---

## 🔧 Troubleshooting

### Issue: "No module named 'utils'"

**Solution:**
```bash
# Make sure you're in the project root
cd /home/tech4biz/work/CP_Front_Automation_Test
source venv/bin/activate
```

### Issue: "TypeError: got multiple values for argument 'headless'"

**Status:** ✅ **FIXED** - This was resolved by adding `user_id` as first parameter

**Verification:**
```bash
python3 tests/load_tests/validate_function_signature.py
```

### Issue: "No students loaded"

**Causes:**
- CSV path is incorrect
- `--start` and `--end` are invalid
- CSV doesn't have `Student CPID` column

**Solution:**
- Check CSV path is correct
- Verify `--start` < `--end`
- Ensure CSV has required columns

### Issue: High Failure Rate

**Possible Causes:**
- Too many concurrent browsers (reduce `--workers`)
- System resources exhausted (RAM/CPU)
- Backend server overloaded
- Network issues

**Solutions:**
- Reduce `--workers` to 20-50
- Monitor system resources (`htop`, `free -h`)
- Check backend server logs
- Test with smaller batch first

### Issue: "DevToolsActivePort file doesn't exist"

**Cause:** Too many Chrome instances trying to start simultaneously

**Solution:**
- Reduce `--workers` (try 20-50)
- Add delay between browser starts
- Use headless mode (`--headless`)

### Issue: Slow Execution

**Causes:**
- Too many concurrent browsers
- System resources limited
- Network latency
- Backend server slow

**Solutions:**
- Use `--headless` mode (faster)
- Reduce `--workers`
- Check network connection
- Monitor backend performance

---

## 💡 Best Practices

### 1. Start Small, Scale Up
- ✅ Test with 1 student first
- ✅ Then 10 students
- ✅ Then 50 students
- ✅ Finally 100+ students

### 2. Use Headless Mode
- ✅ Always use `--headless` for load testing
- ✅ Much faster and more stable
- ✅ Lower resource usage
- ✅ Use `--visible` only for debugging

### 3. Monitor System Resources
```bash
# In another terminal, monitor:
watch -n 1 'ps aux | grep chrome | wc -l'  # Count Chrome processes
htop  # Monitor CPU/RAM
free -h  # Check memory
```

### 4. Validate Before Running
```bash
# Always validate signature first
python3 tests/load_tests/validate_function_signature.py
```

### 5. Use Appropriate Concurrency
- **Small test (1-10 students)**: `--workers` = number of students
- **Medium test (10-50 students)**: `--workers` = 20-50
- **Large test (50-100 students)**: `--workers` = 50-100
- **Very large test (100+ students)**: `--workers` = 100 (or use multi-device)

### 6. Multi-Device Strategy
- Divide students evenly across devices
- Each device runs 100-200 students
- All devices run simultaneously
- Combine results from all devices

### 7. Metrics Interval
- **Short tests (< 50 students)**: `--metrics-interval 5`
- **Medium tests (50-100 students)**: `--metrics-interval 10`
- **Long tests (100+ students)**: `--metrics-interval 20`

---

## 🚀 Advanced Usage

### Custom Range Testing

**Test specific students:**
```bash
# Students 50-75
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students.csv \
    --start 50 \
    --end 75 \
    --workers 25
```

### Resuming Failed Tests

If a test fails, you can resume by running the same command with adjusted `--start`:
```bash
# Original: --start 0 --end 100 (failed at student 50)
# Resume from student 50:
python3 tests/load_tests/test_generic_load_assessments.py \
    --csv students.csv \
    --start 50 \
    --end 100 \
    --workers 50
```

### Performance Analysis

**Analyze JSON report:**
```python
import json

with open('reports/load_tests/load_test_Complete_Assessment_Flow_100users_*.json') as f:
    data = json.load(f)
    
summary = data['summary']
print(f"Success Rate: {summary['success_rate']:.2f}%")
print(f"Avg Duration: {summary['avg_duration']:.2f}s")
print(f"P95 Duration: {summary['p95_duration']:.2f}s")
```

---

## 📝 Notes

### Password Strategy
- **Excel password** is tried first (from CSV)
- **Admin@123** is used as fallback
- Password reset only happens if needed (smart detection)

### Assessment Flow
- Completes **ONE domain** (first unlocked domain)
- Answers **ALL questions** in that domain
- Handles **all 5 question types** automatically
- Submits when all questions answered

### Error Handling
- Robust retry logic for transient failures
- Smart error recovery
- Comprehensive error logging
- Driver cleanup on errors

### Resource Management
- Automatic browser cleanup
- Thread pool management
- Memory-efficient execution
- Progress tracking

---

## ✅ Verification Checklist

Before running a large load test:

- [ ] Virtual environment activated
- [ ] Function signature validated (`validate_function_signature.py`)
- [ ] CSV file exists and has correct format
- [ ] Backend server is running
- [ ] Tested with 1 student first
- [ ] System resources are adequate
- [ ] Using headless mode for load testing
- [ ] Appropriate `--workers` value set
- [ ] Monitoring system resources

---

## 🆘 Getting Help

### Check These First:
1. Run validation script: `python3 tests/load_tests/validate_function_signature.py`
2. Test with 1 student first
3. Check system resources
4. Review error messages in JSON report
5. Check backend server logs

### Common Questions:

**Q: How many students can I run simultaneously?**
A: Depends on system resources. Start with 20-50, scale up based on performance.

**Q: Can I run this on multiple machines?**
A: Yes! Use `--start` and `--end` to divide students across machines.

**Q: How long does it take?**
A: ~3-5 minutes per student. 100 students = ~5-8 hours (depending on concurrency).

**Q: What if a student fails?**
A: The script continues with other students. Check the JSON report for details.

**Q: Can I pause and resume?**
A: Not automatically, but you can use `--start` to resume from a specific index.

---

## 📚 Related Files

- `test_generic_load_assessments.py` - Main load test script
- `validate_function_signature.py` - Signature validation script
- `VERIFICATION_SUMMARY.md` - Issue analysis and resolution
- `LOAD_TEST_USAGE.md` - Quick reference guide

---

**Last Updated:** 2025-12-12
**Status:** ✅ Production Ready - All Issues Resolved