第一行脚本超出了PHP最大执行时间

Question

I'm getting intermittent errors in PHP's own error log like so:

09-Mar-2015 09:18:12 Europe/Dublin] PHP Fatal error: Maximum execution time of 120 seconds exceeded in C:\inetpub\site\www\index.php on line 27

The application runs on CakePHP so index.php is just Cake's normal request handler. Every request to the application goes through this file.

The site runs on PHP 5.4 in Windows/IIS. IIS' own log for this particular request shows this to be a POST request.

This is index.php. Line 27 is the first line of actual code after the comments, therefore it's safe to assume that it's the very first line that PHP tries to execute on the request.

<?php
/**
 * Requests collector.
 *
 *  This file collects requests if:
 *  - no mod_rewrite is available or .htaccess files are not supported
 *  - requires App.baseUrl to be uncommented in app/Config/core.php
 *  - app/webroot is not set as a document root.
 *
 * PHP 5
 *
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright 2005-2012, Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @since         CakePHP(tm) v 0.2.9
 * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 */

/**
 *  Get Cake's root directory
 */
define('APP_DIR', 'app');
define('DS', DIRECTORY_SEPARATOR);
define('ROOT', dirname(__FILE__));
define('WEBROOT_DIR', 'webroot');
define('WWW_ROOT', ROOT . DS . APP_DIR . DS . WEBROOT_DIR . DS);

/**
 * This only needs to be changed if the "cake" directory is located
 * outside of the distributed structure.
 * Full path to the directory containing "cake". Do not add trailing directory separator
 */
if (!defined('CAKE_CORE_INCLUDE_PATH')) {
    define('CAKE_CORE_INCLUDE_PATH', ROOT . DS . 'lib');
}

require APP_DIR . DS . WEBROOT_DIR . DS . 'index.php';

I've got two problems here.

First, what the heck is causing this problem? Some IIS or PHP setting I haven't thought of? I can't reproduce it in development.

Secondly, users who experience this error just get the white screen of death because the CakePHP framework hasn't kicked in yet and registered the shutdown function or error handler. Any interim ideas on how I could handle this with at the very least a graceful "Something went wrong, please try again" would be useful. You can't use register_shutdown_function() in index.php because it then overrides CakePHP's error handler.

Answer 1

The problem turned out to be that max_input_time was set to too low a value. Only users on slow connections who uploaded large files had this problem. I increased max_input_time in php.ini and the problem has disappeared.