> I never claimed any other single point of failure [in user-space] than the service manager.
If all of one's system and service management relies upon a system-wide software "bus", then another similar problem is what to do when one has restarted the "bus" broker service and it has lost track of all active clients and servers.
Related problems are what to do when one cannot shut down one's log daemon because the only way to reach its control interface is via a "bus" broker service, and the broker in turn relies upon logging being available until it is shut down. Again, this is an example of engineering tradeoffs. Choose one big centralized logger daemon for logging everything, and this complexity and interdependence is a consequence. A different design is to have multiple log daemons, independent of one another. With the cyclog@dbus service logging to /var/log and that log daemon's own and the service manager's log output being logged by a different daemon to /run/system-manager/log/, one can shut down the separate logging services at separate points in the shutdown procedure.
If all of one's system and service management relies upon a system-wide software "bus", then another similar problem is what to do when one has restarted the "bus" broker service and it has lost track of all active clients and servers.
* https://bugs.freedesktop.org/show_bug.cgi?id=89847
* https://github.com/NixOS/nixpkgs/issues/7633
Related problems are what to do when one cannot shut down one's log daemon because the only way to reach its control interface is via a "bus" broker service, and the broker in turn relies upon logging being available until it is shut down. Again, this is an example of engineering tradeoffs. Choose one big centralized logger daemon for logging everything, and this complexity and interdependence is a consequence. A different design is to have multiple log daemons, independent of one another. With the cyclog@dbus service logging to /var/log and that log daemon's own and the service manager's log output being logged by a different daemon to /run/system-manager/log/, one can shut down the separate logging services at separate points in the shutdown procedure.
* https://github.com/systemd/systemd/issues/867
* https://bugzilla.redhat.com/show_bug.cgi?id=1214466