The CPU limit is set in the subscription. However, Cgroups does not limit CPU load (actual CPU usage for processes running under subscription system user is higher than expected when checking via # top -c).
User receives email notification regarding CPU usage:
CONFIG_TEXT: The resource usage limit was reached by the subscription example.com at 16:37.
CPU usage: 72 % during 5 minute(s)
CPU usage notification limit is: 49 % per 5 minute(s)
Hard CPU usage limit is: 50 % per 5 minute(s)
Subscription is locked or using a 'custom' service plan.
CPU limit is shown set to 50% in Plesk > Subscriptions > example.com > Customize > RAM, CPU, Disk I/O
CPU limit is set to 1844674407370955% (unlimited) in the file
# cat /etc/systemd/system/<user-id>.slice.d/50-CPUQuota.conf [Slice] CPUQuota=1844674407370955%
Cgroups is misconfigured, or the configuration file was manually updated
Set the required CPU limit in Subscriptions > example.com > Customize > RAM, CPU, Disk I/O > OK per each subscription in locked status or with the 'custom' service plan.