Hi,
For recent versions of sssd, the monitor (the sssd.service) won’t even
start unless at least one domain is configured.
As sssd.conf(5) notes, all sssd services can be socket-activated when
needed. There is no need to list any services in the "services"
parameter in [sssd].
So, this leads to a question: if all configured services are
configured via systemd to start via socket activation… then what is
the monitor actually monitoring? In this configuration, what does it
actually do? And is there any reason to even run the monitor at all?
If the answer is, “the monitor performs necessary housekeeping
functions so it should be running even if all services are
socket-activated,” then shouldn’t it be the case that the monitor
should run even if no domains are configured?
How would you use SSSD without any domain configured?
To answer your question: there was (is) an idea to get rid of the monitor altogether (and to rely on systemd instead).
But currently the monitor performs some tasks, like watching changes in network interfaces, that needs to be moved to other modules.