What specific server metrics can be monitored in PHP for performance optimization?

To monitor server metrics in PHP for performance optimization, you can track metrics such as CPU usage, memory usage, disk I/O, network traffic, and request processing time. By monitoring these metrics, you can identify bottlenecks and optimize your PHP application for better performance.

// Example PHP code to monitor CPU usage
$cpu_usage = sys_getloadavg();
echo "CPU Usage: " . $cpu_usage[0] . "%";