What potential impact can multiple PHP processes have on system performance or resource usage?

Having multiple PHP processes running simultaneously can lead to high CPU and memory usage, potentially causing system performance issues. One way to mitigate this is by limiting the number of concurrent PHP processes that can run at the same time using a process manager like PHP-FPM or by setting up proper resource limits in your server configuration.

// Example configuration for PHP-FPM to limit the number of child processes
pm = dynamic
pm.max_children = 5
pm.start_servers = 2
pm.min_spare_servers = 1
pm.max_spare_servers = 3
pm.max_requests = 500