# ⚠️ CRITICAL: MONITORING INFRASTRUCTURE DISABLED

## Date: August 8, 2025

## IMPORTANT: DO NOT RE-ENABLE THE MONITORING SYSTEMS

The following monitoring and optimization systems have been **permanently disabled** due to causing PHP segmentation faults that crash the entire WordPress/WP-CLI environment:

### Disabled Systems (in class-hvac-plugin.php):
- ❌ `HVAC_Background_Jobs::init()` - Background job processing
- ❌ `HVAC_Health_Monitor::init()` - Health monitoring 
- ❌ `HVAC_Error_Recovery::init()` - Error recovery system
- ❌ `HVAC_Security_Monitor::init()` - Security monitoring
- ❌ `HVAC_Performance_Monitor::init()` - Performance monitoring
- ❌ `HVAC_Backup_Manager::init()` - Backup management
- ❌ `HVAC_Cache_Optimizer::init()` - Cache optimization

### Still Active:
- ✅ `HVAC_Query_Monitor::init()` - Query monitoring (with WP-CLI disabled)

## Symptoms When Enabled:
- PHP Segmentation faults in WP-CLI commands
- HTTP 503 Service Unavailable errors
- Complete site crashes requiring restoration from backup
- FastCGI errors and connection resets

## Root Cause:
The monitoring infrastructure introduced in commit `afc221a9` contains memory corruption issues or infinite loops that cause PHP to crash at the system level.

## DO NOT:
- ❌ Re-enable any of these systems without thorough testing
- ❌ Deploy to production with monitoring enabled
- ❌ Uncomment the initialization calls in class-hvac-plugin.php

## Files Involved:
- `/includes/class-hvac-plugin.php` (lines 349-372)
- `/includes/class-hvac-background-jobs.php`
- `/includes/class-hvac-health-monitor.php`
- `/includes/class-hvac-error-recovery.php`
- `/includes/class-hvac-security-monitor.php`
- `/includes/class-hvac-performance-monitor.php`
- `/includes/class-hvac-backup-manager.php`
- `/includes/class-hvac-cache-optimizer.php`

## Testing Required Before Re-enabling:
1. Isolate each monitoring system individually
2. Test on local development environment first
3. Monitor memory usage and error logs
4. Test all WP-CLI commands
5. Verify no segmentation faults occur
6. Load test with multiple concurrent requests

## Contact:
If you need to re-enable monitoring, thoroughly review and debug the code first. The issue is likely related to:
- Infinite recursion in hook handlers
- Memory leaks in data collection
- Circular dependencies between monitoring systems
- Race conditions in concurrent access

**THIS IS A CRITICAL PRODUCTION ISSUE - PROCEED WITH EXTREME CAUTION**