Long running cron jobs

Nextcloud version (eg, 10.0.2): 11.0.2
Operating system and version (eg, Ubuntu 16.04): CentOS 7
Apache or nginx version (eg, Apache 2.4.25): Apache 2.4.6
PHP version (eg, 5.6): 7.0.x
Is this the first time you’ve seen this error?: not sure if it is actually an error

Can you reliably replicate it? (If so, please outline steps): no

The issue you are facing:

We run cron.php as a cron job that runs every fifteen minutes. We’ve noticed recently that
some cron jobs are running for a long time (and overlapping with other cron.php jobs).
It would appear as though the cron jobs are just not going to run to completion. Is there anything
we can look at- to determine what the cron job might be stuck on doing?

Remember, this information may be requested if it isn’t supplied; for fastest response please provide as much as you can :heart: Feel free to use a pastebin service, otherwise log files can be indented with 4 spaces on each line to present them in a friendlier way on the forum.

Cron sends emails to root with the output of the cron job, so log in as root and check root’s emails, or redirect the output from cron.php to see if it generates any errors. You could also consider turning on logging in PHP.