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Skribent: Daniel Abrecht
Dato:  
Til: dng
Nye-emner: [DNG] Keeping services running: was tiny service state api [WAS: Fwd: init system agnosticism]
Emne: Re: [DNG] tiny service state api [WAS: Fwd: init system agnosticism]
Hi

From my point of view, systemd always tries to keep services running, no
matter how hard they fail, and to mask possible problems when starting a
service, so the service maintainers don't have to fix their service,
which is really unfortunate.

In case of those service state notifications with sd_notify, I think
they are usually used to signal when a service is starting, but not
ready yet. This may seam reasonable at the beginning, but I think it
fixes the problem at the wrong place; When a service needs another
service, but it's temporary unavailable, it should cause an error or
warning to be returned and logged, but it should never be a fatal error
which causes the service to stop. When a service needs to handle this
situation on it's own, it will become more stable over time. If this
task is taken away from it, it will become fragile, and relay on the
service manager. I think this would be really dangerous, because it
could lead to cascades of failing services once one service fails. At
some point, a service manager couldn't possibly handle that anymore and
there would just be waves of restarting and failing processes.

Daniel Abrecht