Webhosting - CRON

In this article you will learn:

• What is and how does CRON work on web hosting
• How to create a script to run CRON
• How to manage CRON tasks
• Common problems
• Frequently Asked Questions

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CRON on Webhosting

CRON, which you can find in the Webhosting administration, is a tool for re-running tasks set by a PHP script stored on the Webhosting. 

The main limitation of CRON web hosting is the number of tasks you can set for the service and the minimum time interval for running these tasks.

• In the basic setup, you can set up to 3 different CRON tasks running at a minimum interval of 1 hour. 
• Use the CRON+ add-on service to increase the maximum number of jobs to 10 and the minimum startup interval to 5 minutes.
• In case of WMS web hosting ⧉ we do not limit the number of CRONs, the minimum time interval is 5 minutes. You do not need to activate any additional service.

Other important information:

• Through CRON you can only call scripts on a specific Webhost, you cannot call other URLs, scripts from another Webhost or run command line.
• The system does not send notifications or further process the output.
• We cannot 100% guarantee that a script will run at the exact minute specified; by the nature of the service, the server runs many scripts at once at given times and execution may be delayed.

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Scripts for running CRON

It is recommended that all the actions to be performed by the CRON script be entered into a single PHP file that you set up for CRON. This script is subject to all the normal rules and restrictions of PHP on web hosting - it works exactly the same as if you were running it in a browser.

CRON allows you to specify script parameters in the URL address, e.g. cron.php?key=123456&param=test. We recommend that you use these parameters, among other things, to protect against accidental execution of the script from the outside, for example by a robot indexing the site files.

Other important information:

• Include a locking system in the script to prevent damage in case of delayed or repeated execution.
• The system doesn't allow HTTP authentication, we recommend to insert a secret string into the URL, which the script will authenticate and then start to perform its main activity.
• Do not limit the script execution to a specific IP, we cannot guarantee that it will not change.

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Managing CRON tasks

To access the CRON task management interface, follow these steps:

1. Log in to the customer administration ⧉.
2. In the top menu, select Hosting Services Webhosting or WMS.
3. Select the service for which you want to set up CRON.
4. Click on CRON in the left menu.

In this interface you can CRONs:

• to establish,
• edit and delete.

Creating a CRON task

You can find the form for creating a new CRON job in the CRON management interface under the overview table. Enter:

• Title. You can set any name.
• Frequency and start dates. The available frequencies (from 5 minutes or 1 hour to 12 hours) depend on the CRON service variant. You can also set the days and times when CRON will run and, if necessary, limit the dates during which the run will occur.
• PHP script URLto trigger CRON. Add parameters directly to the URL, e.g. cron.php?parametr=hodnota. Separate multiple parameters by a character &.

Editing and deleting CRON jobs

To access the CRON job editing interface, click the pencil icon on the left side of the CRON overview.

To delete a CRON job, click the red cross on the left side of the CRON overview.

If you just want to pause the job without deleting it, edit the job so that the To date contains the current date. Deleting this setting resumes the job.

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Common problems

Common problems with CRON include:

• CRON is not triggering
• CRON does not support the required settings

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Frequently Asked Questions