[systemd-devel] systemd and mysql with large memory pages

[Lennart Poettering]

On Mon, 19.09.11 21:29, Reindl Harald (h.reindl at thelounge.net) wrote:

> 
> 
> Am 19.09.2011 20:48, schrieb Lennart Poettering:
> > On Mon, 19.09.11 20:42, Reindl Harald (h.reindl at thelounge.net) wrote:
> >>> limits.conf is generally only applied to logins, not to system services
> >>
> >> i remeber that was the reaso include it in the /etc/initd./service because
> >> started processes from here should use the limits from the
> >> parent-shell
> > 
> > systemd invokes all services in clean defined execution contexts with
> > reset resource limits. This problem should not exist on systemd hence.
> 
> you missunderstood me
> 
> the problem was "limuts.conf" ignored fro mysqld and solved by the
> init-shellscript using ulimit - so with systemd a problem comes back

Well, but there's an equivalent fix here, just use LimitXXX= in the unit
files.

> >> but why is "limits.conf" ignored by services?
> > 
> > It's the configuration file of pam_limits, and since PAM is for user
> > authentication and session management and mysql is a service we don't
> > invoke it
> 
> bad - in my opinion "limts.conf" would be the right place from
> the user-side becasue it affects users/groups and finally services
> are running as a user/group - so sould be there not exist one
> central point of configuration?

Historically it hasn't been used this way and I am not sure this should
change really. limits.conf so far has been something to apply limits to
unprivileged user code. System services generally run without limits
since they are more trusted. And if you set limits you probably want
different per-service limits, since the resources required are very much
dependendent on the service code. 

Lennart

-- 
Lennart Poettering - Red Hat, Inc.