Advanced Cron Troubleshooting - Intermittent Issues
Symptom
You may find that the cron job is not completing intermittently but does complete all of its tasks when you run it via the command line using these steps.
Cause
This type of issue may have many causes. You must perform additional investigation before you can determine next steps.
Investigation
In order to investigate this issue, we recommend logging the output of the cron.php script to a file and then examining its contents.
If you use cPanel & WHM, this includes steps within WHMCS and in cPanel.
For more information for other control panels, see your server's documentation.
To investigate this issue on a cPanel & WHM server:
1. In the WHMCS Admin Area, go to the Other tab at Configuration > System Settings > General Settings or, prior to WHMCS 8.0, Setup > General Settings.
2. Select Display Errors.
3. Click Save Changes.
4. In cPanel, go to Advanced >> Cron Jobs.
5. Click Edit for the cron job command that references the cron.php file:
6. For Command, append the following code to the end of the line:
-vvv >> crondebug.txt
7. Click Edit Line.
8. Wait until the Time of Day window has passed. For example, if the Time of Day setting is 1pm, wait until 2pm.
9. Open the crondebug.txt file in your account's root directory. This file contains entries from each invocation of the cron.php script.
10. Review the file contents to locate the daily automation tasks. To find this, look for 24 or more tasks that queued for execution.
These will resemble the following examples:
- An error during execution:
WHMCS Automation Task Utility: all
==================================
Queuing Tasks
-------------
Applying "in progress" and "is due" state filters
Task queues ready
Executing Application Queue
---------------------------
Currency Exchange Rates
Product Pricing Updates
Tenant Usage Metrics
[ERROR] WHMCS\Exception\Module\NotServicable: Connection Error: Could not resolve host: fakeservertest(6) in
/home/v80whmcssupport/public_html/whmcs/modules/servers/cpanel/cpanel.php:0 - A successful execution:
WHMCS Automation Task Utility: all
==================================
Daily Cron Automation Mode
Queuing Tasks
-------------
Applying "in progress" and "is due" state filters
Task queues ready
Executing Application Queue
---------------------------
Currency Exchange Rates
Product Pricing Updates
Invoices
Late Fees
Credit Card Charges
Invoice & Overdue Reminders
Domain Renewal Notices
Cancellation Requests
Overdue Suspensions
Overdue Terminations
Fixed Term Terminations
Inactive Tickets
Delayed Affiliate Commissions
Email Marketer Rules
SSL Sync
Server Usage Stats
Client Status Update
Domain Expiry
Ticket Escalation Rules
Data Retention Pruning
WHMCS Updates
Run Jobs Queue
Sending Daily Cron Digest email
Executing System Queue
----------------------
[OK] Completed11. Use the explanations of common errors in our documentation to continue resolving the issue.
WHMCS Technical Support can help you with these errors. When you open your support ticket, make sure to include the full output in your crondebug.txt file.