PHP backup script timing out

I have a backup script which backups up all files for a website to a zip file (using a script similar to the answer to this question). However, for large sites the script times out before it can complete.

Is there any way I can extend the length of time available for the script to run? The websites run on shared Windows servers, so I don't have access to the开发者_开发问答 php.ini file.

If you are in a shared server environment, and you don’t have access to the php.ini file, or you want to set php parameters on a per-site basis, you can use the .htaccess file (when running on an Apache webserver).

For instance, in order to change the max_execution_time value, all you need to do is edit .htaccess (located in the root of your website, usually accesible by FTP), and add this line:

php_value max_execution_time 300

where 300 is the number of seconds you wish to set the maximum execution time for a php script.

There is also another way by using ini_set function in the php file

eg. TO set execution time as 5 second, you can use

ini_set('max_execution_time', 300); //300 seconds = 5 minutes

Please let me know if you need any more clarification.

set time limit comes to mind, but may still be limited by php.ini settings

set_time_limit(0);

http://php.net/manual/en/function.set-time-limit.php

Simply put; don't make a HTTP request to start the PHP script. The boundaries you're experiencing are set because you're using a HTTP request, which means you can have a time-out. A better solution would be to implement this using a "cronjob", or what Microsoft calls "Scheduled tasks". Most hosting providers will allow you to run such a task at set times. By calling the script from command line, you don't have to worry about the time-outs any more, but you're still at risk of running into memory issues.

If you have a decent hosting provider though, why doesn't it provide daily backups to start with? :)

You can use the following in the start of your script:

<?php
if(!ini_get('safe_mode')){ 
        set_time_limit(0); //0 in seconds. So you set unlimited time
}
?>

And at the end of the script use flush() function to tell PHP to send out what it has generated.

Hope this solves your problem.

Is the script giving the "Maximum execution time of xx seconds exceeded" error message, or is it displaying a blank page? If so, ignore_user_abort might be what you're looking for. It tells php not to stop the script execution if the communication with the browser is lost, which may protect you from other timeout mechanisms involved in the communication.

Basically, I would do this at the beginning of your script:

set_time_limit(0);
ignore_user_abort(true);

This said, as advised by Berry Langerak, you shouldn't be using an HTTP call to run your backup. A cronjob is what you should be using. Along with a set_time_limit(0), it can run forever.

In shared hosting environments where a change to the max_execution_time directive might be disallowed, and where you probably don't have access to any kind of command line, I'm afraid there is no simple (and clean) solution to your problem, and the simplest solution is very often to use the backup solution provided by the hoster, if any.

Try the function:

set_time_limit(300);

On windows, there is a slight possibility that your webhost allows you to over ride settings by uploading a php.ini file in the root directory of your webserver. If so, upload a php.ini file containing:

max_execution_time = 300

To check if the settings work, do a phpinfo() and check the Local Value for max_execution_time.

Option 1: Ask the hosting company to place the backups somewhere accesible by php, so the php file can redirect the backup.

Option 2: Split the backup script in multiple parts, perhaps use some ajax to call the script a few times in a row, give the user a nice progress bar and combine the result of the script calls in a zip with php and offer that as a download.