Running moodle 3.9.6, PHP 7.4, on Ubuntu 18 (under Apache with MySqli)
After upgrading to moodle 3.9, I found enrolments weren't updating from an external db. Looking at scheduled tasks and running cron manually, I got this:
Execute scheduled task: Background processing for Dropbox repository (repository_dropbox\task\cron_task)
... started 07:35:27. Current memory use 15.7MB.
Meanwhile, watching in top, one finds php takes all available memory and then we get numerous reports of:
[51100.553022] Out of memory: Killed process 14763 (php7.4) total-vm:8894444kB, anon-rss:8446732kB, file-rss:0kB, shmem-rss:0kB, UID:0 pgtables:17284kB oom_score_adj:0
I then tried limiting php's memory use, but the result is that although the OS doesn't kill all the processes, php itself stops the process before the dropbox task or any other task is completed:
PHP Fatal error: Allowed memory size of 8589934592 bytes exhausted (tried to allocate 20480 bytes) in /var/www/online.blconlinecourses.com/public_html/repository/lib.php on line 570
PHP Fatal error: Allowed memory size of 8589934592 bytes exhausted (tried to allocate 20480 bytes) in /var/www/online.blconlinecourses.com/public_html/lib/classes/task/database_logger.php on line 68
So I found this process in scheduled tasks: "Background processing for Dropbox repository" and I disabled it.
Now, enrolments sync 😅, and I also find that I can browse to my Dropbox folder in the File Picker and still see and pick the resources from that repository 🤔.
So, I am wondering: What does the "Background processing for Dropbox repository" actually do? Is there a way to successfully run it in my situation? Is it necessary to run it? If we get a successful first run, might the load get lighter so that it could actually run as a scheduled task?
Thankful for insight and help from fellow moodlers!