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Webhosting - CRON

In this article, you will learn:

CRON on Webhosting

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

CRON on Webhosting is a significantly simplified and limited version of the Linux tool of the same name. It is intended for running PHP scripts, not Bash commands.

The main limitation of Webhosting CRON 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 configure up to 3 different CRON tasks on Webhosting, run at a minimum interval of 1 hour. 
  • With the CRON+ add-on service, you increase the maximum number of tasks to 10 and the minimum running interval to 5 minutes.
  • In the case of WMS hosting ⧉, we do not limit the number of CRONs, and the minimum interval is 5 minutes. You do not need to activate any paid add-on service.

Additional important information:

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

Scripts for CRON execution

We recommend placing all actions that the script executed by CRON should perform into one PHP file that you set up for CRON. This script is subject to all standard PHP rules and limitations on Webhosting – it works exactly the same as if you ran it in a browser.

PHP scripts run by CRON cannot interfere with PHP settings or the Webhosting operating system.

CRON allows you to pass script parameters in the URL, e.g. cron.php?key=123456&param=test. We recommend using these parameters, among other things, as protection against accidental execution of the script from outside, for example by a bot indexing website files.

Additional important information:

  • Include a locking system in the script to prevent damage in case of delayed or repeated execution.
  • The system does not allow HTTP authentication; we recommend placing a secret string in the URL that the script verifies before starting its main activity.
  • Do not restrict script execution to a specific IP, as we cannot guarantee that it will not change.

Managing CRON tasks

To enter 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. In the left menu, click CRON.
Manage Webhosting CRON
Manage WMS Webhosting CRON
Enter the CRON task management interface
Enter the CRON task management interface

In this interface, you can:

Creating a CRON task

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

  • Name. You can set any name.
  • Frequency and run dates. The available frequencies (from 5 minutes or 1 hour up to 12 hours) depend on the CRON service variant. You can also set the days and times when CRON should run and optionally limit the dates during which execution will take place.
  • URL of the PHP script that CRON should run. Add parameters directly to the URL, e.g. cron.php?parametr=hodnota. Separate multiple parameters with the & character.
Example of creating a new CRON task
Example of creating a new CRON task

Editing and deleting a CRON task

To open the CRON task editing interface, click the pencil icon on the left side of the CRON overview.

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

Icons for editing and deleting a CRON task
Icons for editing and deleting a CRON task

If you want to only pause a task without deleting it, edit it so that End date contains the current date. Deleting this setting will resume the task.

Common problems

Common CRON problems include:

CRON does not run

Problem: CRON does not run the configured script.

Cause: CRON is paused or calls a non-existent script. The error may also be in the script itself.

Solution: Perform the following checks:

  1. In the CRON task management interface, check that the next run is scheduled.
  2. In the browser, verify that the script runs correctly when you enter the full address including the protocol and parameters.
Materials for checking CRON scripts
Materials for checking CRON scripts

If the script is scheduled correctly and works in the browser, but CRON still does not run it, set up a temporary FTP access for support according to this guide and send a detailed description of the problem via the form ⧉.

Cannot enter the required settings

Problem: The manual for my application asks me to set up CRON, but the scripts cannot be entered in your administration according to the instructions.

Cause: The application often uses the term CRON to mean the Linux tool that runs terminal commands. However, Webhosting CRON supports only running PHP files.

Solution: Try to achieve the required results with a PHP script that CRON can call.

Frequently asked questions

What if I need more than 3 CRONs on Webhosting?

The CRON+ add-on service increases the maximum number of tasks to 10 and the minimum running interval to 5 minutes.

How do I get to more detailed CRON settings?

We do not provide more detailed settings in the Webhosting interface. However, you can specify conditions directly in the PHP script that CRON runs.

What are parameters?

Parameters in the URL are standard PHP GET parameters.

If I have CRON+, do my scripts have priority over scripts of regular users?

No, when scripts are called at the given time, scripts of users with CRON+ are not given any priority.

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