Are you having issues with SSSD_BE hogging CPU in an environment where you do have AD configured, but majority of the users are local to your Linux server?
Well, these options should help you dealing with this issue:
enable_file_domains = false
/etc/nsswitch.conf order, instead of having: sss files, change it to files sss
The enable_file_domains option will not start an SSSD instance for local files, it will only use SSSD for AD sources, if you have them configured in your sssd.conf file. That is usually the cause for the high CPU usage.
A few other options that can help contribute with high CPU usage around SSSD in large AD environments are:
enumeration=true
ignore_group_members=false
Usually, it is recommended to disable enumeration and enable ignore_group_members.