[systemd-devel] what does systemd do if the syslogd errs on start?

[Rainer Gerhards]

On Wed, Jul 6, 2011 at 4:17 PM, Lennart Poettering
<lennart at poettering.net> wrote:
> On Wed, 06.07.11 16:11, Rainer Gerhards (rgerhards at gmail.com) wrote:
> Yes, if rsyslog dies, then systemd will notice it. As soon as there is
> traffic on the /dev/log socket (which might be right-away) it will then
> start the syslog-kmsg bridge again.

Will systemd make any attempt to restart syslogd if it failed? I think
there is pros and cons in it:

a) if syslogd failed due to config error, a restart is bad
b) if syslogd failed for stability reason, a reasonable number of
restarts may make sense

I assume that the user can always make systemd restart syslogd, e.g.
after fixing a conf problem.

> So we should be reasonably safe here
> that nothing is completely lost when rsyslog dies.
>
> From a client perspective nothing of this is visible. Clients can jus
> use syslog(), and this will go to rsyslog as long as it is started, and
> to kmsg before rsyslog started and after it died (regardless whether
> that was abnormally or cleanly).

Let's make sure we are on the same line. Sequece of events:

1. systemd starts syslogd
2. syslogd parses config, detects errors
3. syslogd logs config errors via syslog()
4. syslogd terminates

Will that work? Note that at #3, syslogd has not yet terminated, so
from a systemd POV it will probably look healthy.

Having said that, would it make sense to somehow make syslogd flag
systemd that it had a successful startup and is now ready to process
messages?

Rainer