Re: [DIFF] /etc/rc: gracefully shut down base daemons too
init shuts them down gracefully anyway where possible. When you have a misbehaving system, the fewer unnecessary processes to get in the way of a reboot, the better. On 21 February 2015 07:45:13 GMT+00:00, skin...@britvault.co.uk wrote: On 2015-02-20 Fri 18:12 PM |, Ingo Schwarze wrote: Craig Skinner wrote on Fri, Feb 20, 2015 at 04:41:17PM +: Changed to skip pflogd, syslogd check /var/run/rc.d/ No, we don't want it, and we have given reasons Which problem are you trying to solve? OpenBSD runs great Ingo. I guessed gracefully shutting down daemons was the decent thing to do. Oh well. for the archives, in case there is a future need. -- Sent from a phone, please excuse the formatting.
Re: [Bulk] Re: [DIFF] /etc/rc: gracefully shut down base daemons too
On Sat, 21 Feb 2015 11:19:08 + Stuart Henderson wrote: init shuts them down gracefully anyway where possible. When you have a misbehaving system, the fewer unnecessary processes to get in the way of a reboot, the better. I've certainly had Linux hang on shutting down services more than once and never on OpenBSD. I guess less is more, proves itself again. Systemd may have improved the Linux shutdown with cgroups though I'm not convinced?? (by doing even more) and it's brought all sorts of other reliability problems to the table.
Re: [DIFF] /etc/rc: gracefully shut down base daemons too
On 2015-02-20 11:12 AM, Ingo Schwarze wrote: Hi Craig, Craig Skinner wrote on Fri, Feb 20, 2015 at 04:41:17PM +: Changed to skip pflogd, syslogd check /var/run/rc.d/ No, we don't want it, and we have given reasons: It makes the code longer, more fragile, and provides no known benefit whatsoever. Fixing the most blatant downsides does not change that. Which problem are you trying to solve? Yours, Ingo Two daemons that would very much matter are ospfd and bgpd. Normally, doing a clean shutdown of bgpd is the LAST thing I want, because that would break BGP graceful-restart - that capability relies on BGP simply disappearing. If I shut down BGPd, I withdraw all my prefixes. A clean shutdown of BGP can take several minutes; only very rarely would I want to sit and wait for BGPd to shut down before rebooting. (Ospfd would be similarly affected IIRC.) And by the time we get to special-casing half the daemons in base, what's the point? Doing a clean shutdown of nfsd (or lockd or statd) would be harmful to certain clients that would otherwise survive the nfsd reboot. Ditto for iked, sasyncd, iscsid, ldpd, and possibly even ntpd (not sure about that one). Client-server protocols are generally written to retry on, or otherwise be resilient to, failure; signalling shutdown when I have to kick the server in the head for some reason (which, yes, even happens with OpenBSD :-)) would be a bad thing for some to many clients. -- -Adam Thompson athom...@athompso.net
Re: [DIFF] /etc/rc: gracefully shut down base daemons too
Hi Craig, Craig Skinner wrote on Fri, Feb 20, 2015 at 04:41:17PM +: Changed to skip pflogd, syslogd check /var/run/rc.d/ No, we don't want it, and we have given reasons: It makes the code longer, more fragile, and provides no known benefit whatsoever. Fixing the most blatant downsides does not change that. Which problem are you trying to solve? Yours, Ingo
Re: [DIFF] /etc/rc: gracefully shut down base daemons too
On 2015-02-17 Tue 14:24 PM |, Antoine Jacoutot wrote:
On Tue, Feb 17, 2015 at 01:20:03PM +, Craig Skinner wrote:
Produces (on 5.6 release) - with start up order reversed:
root@box:~ 0# halt -p
stopping package daemons: greyscanner postfix sshguard.
stopping base daemons: cron spamlogd spamd sshd ntpd unbound nsd pflogd
syslogd.
syncing disks... done
I cooked a patch for that a few months ago (actually 1 year ago iirc) but we
decided not to go down that road for a reason I cannot recall right now.
And I was using the information from /var/run/rc.d instead to know what to
shutdown exactly instead of greping /etc/rc.
Changed to skip pflogd, syslogd check /var/run/rc.d/
Index: rc
===
RCS file: /cvs/src/etc/rc,v
retrieving revision 1.447
diff -u -p -r1.447 rc
--- rc 22 Jan 2015 19:00:24 - 1.447
+++ rc 20 Feb 2015 16:38:49 -
@@ -131,17 +131,42 @@ fill_baddynamic()
}
}
-start_daemon()
+start_stop_daemon()
{
- local _n
- for _n; do
- eval _do=\${${_n}_flags}
- if [ X${_do} != XNO ]; then
- /etc/rc.d/${_n} start
- fi
+ local _start_stop=$1
+ local _daemon _daemon_script
+ shift
+
+ for _daemon
+ do
+ eval _do=\${${_daemon}_flags}
+ [[ ${_do} == 'NO' ]] continue
+
+ _daemon_script=/etc/rc.d/${_daemon}
+ [[ -e ${_daemon_script} ]] ||
+ {
+ print -n -- ${_daemon}(absent)
+ continue
+ }
+ [[ -x ${_daemon_script} ]] ||
+ {
+ print -n -- ${_daemon}(inexecutable)
+ continue
+ }
+ ${_daemon_script} ${_start_stop}
done
}
+start_daemon()
+{
+ start_stop_daemon 'start' $*
+}
+
+stop_daemon()
+{
+ start_stop_daemon 'stop' $*
+}
+
make_keys()
{
if [ ! -f /etc/isakmpd/private/local.key ]; then
@@ -269,12 +294,26 @@ if [ X$1 = Xshutdown ]; then
while [ -n ${pkg_scripts} ]; do
_r=${pkg_scripts##* }
pkg_scripts=${pkg_scripts%%*( )${_r}}
- [ -x /etc/rc.d/${_r} ] /etc/rc.d/${_r} stop
+ stop_daemon ${_r}
done
echo '.'
fi
[ -f /etc/rc.shutdown ] sh /etc/rc.shutdown
+
+ print -n 'stopping base daemons:'
+ set -A _daemons $(egrep start_daemon[[:blank:]][[:alnum:]]
/etc/rc)
+ for _daemon in $(jot ${#_daemons[*]} ${#_daemons[*]} 1)
+ do
+ _daemon=${_daemons[${_daemon}]}
+ [[ ${_daemon} == 'start_daemon' ]] continue
+ [[ -f /var/run/rc.d/${_daemon} ]] || continue
+ [[ ${_daemon} == 'pflogd' ]] continue
+ [[ ${_daemon} == 'syslogd' ]] continue
+ stop_daemon ${_daemon}
+ done
+ print '.'
+
else
echo single user: not running shutdown scripts
fi
@@ -513,11 +552,7 @@ rm -f /etc/rc.firsttime.run
if [ -n ${pkg_scripts} ]; then
echo -n 'starting package daemons:'
for _r in $pkg_scripts; do
- if [ -x /etc/rc.d/${_r} ]; then
- start_daemon ${_r}
- else
- echo -n ${_r}(absent)
- fi
+ start_daemon ${_r}
done
echo '.'
fi
Re: [DIFF] /etc/rc: gracefully shut down base daemons too
On 2015-02-20 Fri 18:12 PM |, Ingo Schwarze wrote: Craig Skinner wrote on Fri, Feb 20, 2015 at 04:41:17PM +: Changed to skip pflogd, syslogd check /var/run/rc.d/ No, we don't want it, and we have given reasons Which problem are you trying to solve? OpenBSD runs great Ingo. I guessed gracefully shutting down daemons was the decent thing to do. Oh well. for the archives, in case there is a future need. -- Do you cheat on your wife? asked the psychiatrist. Who else? answered the patient.
Re: [DIFF] /etc/rc: gracefully shut down base daemons too
Hi, Antoine Jacoutot wrote on Tue, Feb 17, 2015 at 02:24:56PM +0100: On Tue, Feb 17, 2015 at 01:20:03PM +, Craig Skinner wrote: stopping base daemons: cron spamlogd spamd sshd ntpd unbound nsd pflogd syslogd. syncing disks... done I cooked a patch for that a few months ago (actually 1 year ago iirc) but we decided not to go down that road for a reason I cannot recall right now. I guess the point was that it's nothing but useless complexity. I see how a clean shutdown might matter for, say, postgres. But what is the point in shutting down cron, sshd, ntpd, or unbound right before the system is going down anyway? Shutting down stuff like pflogd and syslogd before the system is actually going down might even be harmful. If it turns out there are one or two base daemons where shutting them down by running the rc.d(8) script is better than what currently happens, those one or two could get special handling in /etc/rc itself. But so far, i don't remember that anybody ever saw a specific need for any of them. Yours, Ingo
Re: [DIFF] /etc/rc: gracefully shut down base daemons too
I see how a clean shutdown might matter for, say, postgres. But what is the point in shutting down cron, sshd, ntpd, or unbound right before the system is going down anyway? Shutting down stuff like pflogd and syslogd before the system is actually going down might even be harmful. If it turns out there are one or two base daemons where shutting them down by running the rc.d(8) script is better than what currently happens, those one or two could get special handling in /etc/rc itself. But so far, i don't remember that anybody ever saw a specific need for any of them. I fully agree. -- Antoine
Re: [DIFF] /etc/rc: gracefully shut down base daemons too
On 02/17/15 08:52, Ingo Schwarze wrote: ... Shutting down stuff like pflogd and syslogd before the system is actually going down might even be harmful. you mean...like maybe when doing an upgrade where the newly installed binaries are not compatible with the running kernel? Considering the number of times base daemons have been shut down by halting the kernel and the lack of problems caused by this? no...I don't think this is a good idea at all. Nick.
