[systemd-devel] How to quiet cron sessions logging with systemd-212?

[Reindl Harald]

Am 09.06.2014 22:32, schrieb Leonid Isaev:
> On Mon, Jun 09, 2014 at 09:19:20PM +0200, Reindl Harald wrote:
>> [...]
>>
>> on our production infrastrcuture these messages would be
>> *a lot* more than all other logs summarized
>>
>> *and* they are spitted to /var/log/messages to make things worst
>>
>>> But why can't you write a syslog filter which uses facility as well as program
>>> name? So if you believe that systemd-generated messages are useless, drop them
>>
>> because you *can not* distinguish between *that* user messages
>> and system message sbecause they have systemd as program name
>> common, the PID changes and you don't want to drop *system
>> messages* from systemd
> 
> So, systemd starts certain things on _any_ user "login": be it a real user, or
> a daemon. However

* why do it need to do that much stuff
* why can't it keep that stuff long-running

you have already "/usr/lib/systemd/systemd --user" and "(sd-pam)"
processes for every userid ever started a cronjob running all
the time - so why flood the logs every minute again?

> if you already have logs from the daemon (cron) or a login
> program (login), why keep systemd-generated messages? I'd put them in a
> separate file...

if i can put them in a seperate file i can filter them out

>> if they would contain a unique string / prefix to distinguish
> 
> Do you have something concrete in mind?

systemd-user: or whatever

that would also make clear the we *do not* start all sorts
of targets, the flooding log in misleading anyways

that below is just *not true* from the users point of view

Jun  9 22:36:07 rawhide systemd[1]: Starting User Manager for UID 0...
Jun  9 22:36:07 rawhide systemd[607]: Starting Paths.
Jun  9 22:36:07 rawhide systemd[607]: Reached target Paths.
Jun  9 22:36:07 rawhide systemd[607]: Starting Timers.
Jun  9 22:36:07 rawhide systemd[607]: Reached target Timers.
Jun  9 22:36:07 rawhide systemd[607]: Starting Sockets.
Jun  9 22:36:07 rawhide systemd[607]: Reached target Sockets.
Jun  9 22:36:07 rawhide systemd[607]: Starting Basic System.
Jun  9 22:36:07 rawhide systemd[607]: Reached target Basic System.
Jun  9 22:36:07 rawhide systemd[607]: Starting Default.
Jun  9 22:36:07 rawhide systemd[607]: Reached target Default.
Jun  9 22:36:07 rawhide systemd[607]: Startup finished in 9ms.
Jun  9 22:36:07 rawhide systemd[1]: Started User Manager for UID 0.

>> from cronjobs triggered messages i would have written a rsyslog
>> filter as for a lot of other noise long ago
>>
>> however - the *large amount* of that messages even if you
>> drop them consumes useless ressources on virtualization
>> clusters and blow up the systemd-journal
> 
> If resources are an issue, don't use the journal. In my experience, it consumes
> ~4x space compared to syslog (on a firewall machine, after 2 months uptime)...

i don't use the journal, the configuration of journald is like below
the log-flood makes things even worser because it leads to early
rotation and purges "systemctl status whatever.service" informations
by purging the memory-journal

if it comes to ressource usage:

all that dropped messages (if you could drop/filter them) are
producing data and overhead in general, only because you manage
to not see things that don't mean they produce no overhead

[root at rawhide ~]# cat /etc/systemd/journald.conf
[Journal]
Storage=volatile
Compress=no
RateLimitInterval=10s
RateLimitBurst=500
RuntimeMaxUse=15M

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