You can make this same mistake in PHP blocking operations with 1 worker process in mod_php, php-fpm, or handling sockets directly. The fix is pretty standard: r

You can make this same mistake in PHP blocking operations with 1 worker process in mod_php, php-fpm, or handling sockets directly. The fix is pretty standard: run multiple processes, threads, or use non-blocking operations. The most common PHP setups are simply running multiple processes behind a httpd daemon, so this problem is less frequently encountered. But it's still lurking at a certain concurrency level.