How to run Drupal cron maintenance tasks under Mosso hosting

Update: Mosso was rebranded as The Rackspace Cloud in June 2009.

Update 1 Jan 2010: It looks like Rackspace has fixed the problem with Mosso's Scheduled Tasks. Anonymous' comment tipped me off that you can now set the command language to http, then enter your site's cron.php as the command to run.

If you host a Drupal site on Mosso (now The Rackspace Cloud), there's a good chance that you're using Poor man's Cron to run the maintenance tasks. Poor man's Cron does a good job but it can cause problems, such as irregular cron job runs and extra load on your hosting environment. This guide will show you how to use Mosso's Scheduled Tasks to run Drupal's cron maintenance (cron.php) file.

Since Mosso's Scheduled Tasks control doesn't allow you to run system commands as you would with standard cron jobs, it's not immediately obvious how to apply the instructions in drupal.org's Beginner's guide for Cron. What you'll need to do is use it to kick-off a perl script that runs curl.

Setting up the Scheduled Task

1. First create a simple perl script with the following lines:

#!/usr/bin/perl -w
system ("curl --silent --compressed http://example.com/cron.php");

Remember to replace example.com with your site's domain. Save the script as cron.pl and set the execute bits on the file's permissions.

2. Upload the script to your Mosso Cloud Site. I put mine under a scripts directory above web/content:

/mnt/target05/123456/example.com/scripts/cron.pl

3. Login to your Mosso control panel, select your Cloud Site and click the Features tab. Click Add New Task under the Scheduled Tasks (Cron Jobs) section.

4. Enter your cron settings:

• Status: set to ON
• Task Name (Common Name): Give this task a name
• Email Address for Output: enter noreply@mosso.com if you don't want to receive notifications about the task's execution result
• Command Language: set to perl
• Command to Run: set to scripts/cron.pl

5. Click Save Task. You should now have a cron job set to run Drupal's maintenance cron.php file at your specified intervals.

Testing the Scheduled Task

It's a good idea to test the Scheduled Task by entering your email address for the output and setting the frequency to repeat every 5 minutes. Wait for an email from Task Scheduler. If the task executed successfully, the body should look something like this:

This is an automatically created email, sent to inform you that your scheduled task has completed. Here are the results of the execution of your task:

Task Started at DayOfWeek Mon Day Time
--------------------------------------
Command to be executed is: /usr/bin/perl /mnt/Target00/123456/example.com/scripts/cron.pl
Task ID of this command is: 12345
Where should log be written: /mnt/Target00/123456/example.com/logs
Email address: user@example.com

--------------------------------------
Task ended at DayOfWeek Mon Day Time

If you have any questions please do not hesitate to contact us.

Website Support Team

Now log in to your Drupal site and view the page Administer > Logs > Status report. Check that the Last run time under Cron maintenance tasks roughly corresponds to your cron job set in the Mosso control panel.