The server is slow, web-server constantly crashes, the output of top utility shows that systemd process consumes about 100% CPU.
/run/systemd/systemcontains a lot of objects.
# ls /run/systemd/system | wc -l
The issue caused by the bug registered with ID #PPPM-7414. It will be fixed in future Plesk updates.
As a workaround:
Connect to the server via SSH;
Execute the following command to remove all abandoned scopes:
# systemctl |grep "abandoned" |sed "s/\.scope.*/.scope/" |xargs systemctl stop
Note: To avoid the issue recur it would be also helpful to create a cron task with the command executed every hour.