[#47217] - [5.4] Fix scheduled tasks stopping when one task gets stuck
- Fixed in Code Base
- 8 Mar 2026
- Medium
- Build: 5.4-dev
- # 47217
- Diff
- joomdonation:fix_scheduled_tasks
User tests: Successful: Unsuccessful:
Pull Request resolves # .
- I read the Generative AI policy and my contribution is either not created with the help of AI or is compatible with the policy and GNU/GPL 2 or later.
Summary of Changes
Sometimes a scheduled task may stop unexpectedly (for example due to a timeout or server issue). When this happens, the task remains marked as “locked”.
Currently, if a task is locked, Joomla assumes it is still running even if it is already timed out (the default time out for a scheduled task is 300 seconds). This prevents all other scheduled tasks from being executed.
This PR updates the Scheduler so that if a task has been locked longer than the configured timeout, it will no longer block other scheduled tasks. This allows the Scheduler to recover automatically if a task gets stuck.
Testing Instructions
- Use Joomla 5.4
- Access to System - Scheduled Tasks:
- Disable all tasks and only keep the first two scheduled tasks enabled (to make it easier to monitor): Rotate Logs (ID = 1) and Session GC (ID = 2)
- Edit the two scheduled tasks, configure it so that it is executed every 1 minute
- Access to Options button in the toolbar, click on Lazy Scheduler, set Request Interval (seconds) to 30 instead of 300 by default.
- Access to frontend of your site and wait for Joomla trigger scheduled tasks. Wait for 1 or 2 minutes, then refresh the scheduled tasks page, make sure the tasks are executed (the Last Run Date column updated)
- Access to your site database via PHPMYADMIN, run this SQL command to have the first task locked (remember to replace jos_scheduler_tasks with correct table name, depends on the database table prefix uses on your site)
UPDATE `jos_scheduler_tasks` SET `locked`='2025-02-24 21:56:11' WHERE `id`=1;- Then access to System - Scheduled Tasks again, and wait for one or two minutes. Refresh the page
Actual result BEFORE applying this Pull Request
When there is a task locked (after you run the SQL command above), that locked task will prevent all other tasks (including itself) from being executed. So you do not see Last Run Date updated anymore.
Expected result AFTER applying this Pull Request
The scheduled tasks will continue being executed as expected. A crashed/none finished running task won't block other tasks from being executed.
Link to documentations
Please select:
-
Documentation link for guide.joomla.org:
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No documentation changes for guide.joomla.org needed
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Pull Request link for manual.joomla.org:
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No documentation changes for manual.joomla.org needed
Votes
| Status | New | ⇒ | Pending |
joomla-cms-bot
- | Category | ⇒ | Administration |
I have tested this item ✅ successfully on 3e3545d
postgres 15
This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/47217.
I have tested this item ✅ successfully on 3e3545d
MySQL
This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/47217.
I have tested this item ✅ successfully on 3e3545d
This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/47217.
| Status | Pending | ⇒ | Ready to Commit |
| Labels |
Added:
bug
PR-5.4-dev
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RTC
This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/47217.
| Labels |
Added:
RTC
|
||
✅ Final test before merge using JBT
- Note: JBT is using cron based scheduler, but the problem could not be reproduced with cron based scheduler:run
- Deleted the cron entry and enabled Lazy Scheduler
- Tested two times, once with MariaDB and once with PostgreSQL
- Checked in backend tasks are executed every minute and double checked in
joomla_scheduler.phplog file - Locked one task, seen no task is executed anymore
- Applied PR with Patch Tester
- Seen all tasks are running again and ¿as side effect? also the locked task is no more locked and executed again
- Checked in backend tasks are executed every minute and double checked in
| Status | Ready to Commit | ⇒ | Fixed in Code Base |
| Closed_Date | 0000-00-00 00:00:00 | ⇒ | 2026-03-08 06:08:38 |
| Closed_By | ⇒ | muhme |
Thank you @joomdonation for your contribution. Thank you @alikon, @dautrich and @krishnagandhicode for testing.
Thanks !
I would like to provide more information in case someone wants to understand the issue and the solution while doing code review.
schedulerunnersystem plugin. Before injecting the JS script, Joomla checks whether scheduled tasks should run, the check is called here. That check calls thehasDueTasks()method in the TasksModel modelCurrently, this method returns
falseif there is any locked task, without checking the configured timeout. So if a task does not finish its execution (for example due to timeout or crash), Joomla still thinks it is running. Because of that, the JS script is no longer injected, and scheduled tasks are never triggered again.In this PR, that method is modified so that a task is only considered running if it is locked and not timed out. This allows Joomla to continue injecting the script and triggering scheduled tasks.
Currently,
hasRunningTasks()returnstrueif there is any locked task and does not consider the timeout setting. So if a task crashes and remains locked, Joomla will stop executing all other tasks. This PR modifies that method so it only returnstrueif there is an actual running task (locked and not timed out).Because of this behavior, we have received reports such as #46103, when a task like update notification failed, it prevent all other scheduled tasks such as Session GC stop running, causing the session table to grow large and potentially affecting site performance.
This change makes the Scheduler respect the configured timeout and prevents a stuck task from blocking other scheduled tasks. Hopefully we will get this issue fixed so that Scheduled task will be more reliable.