maria-discuss team mailing list archive

[Matthew Pash <matthew.pash@xxxxxxxxxxxxx>]

I've managed to resolve this, and it appears to have been a problem with
mysqladmin not reading it's defaults when run from cron.

For the benefit of anyone else with the same issue, /etc/logrotate.d/mysql
now looks like this:

/var/log/mysql/mysqld.log {
  compress
  daily
  missingok
  notifempty
  rotate 3
  postrotate
        if test -x /usr/bin/mysqladmin && /usr/bin/mysqladmin ping
&>/dev/null
    then
    /usr/bin/mysqladmin --defaults-file=/root/.my.cnf flush-logs
    fi
  endscript
}

The only change (from RPM new) is adding the defaults-file flag to the
mysqladmin command.  Since adding that everything seems to be working fine.

Thanks for your help.
~Matt


On 31 March 2017 at 00:23, Daniel Black <daniel.black@xxxxxxxxxxx> wrote:

>
>
> On 30/03/17 20:46, Matthew Pash wrote:
> > Morning Daniel,
> >
> > Thanks for your reply, I've been doing some more testing.  The logrotate
> > script (below) currently runs fine when executed manually (sudo
> > logrotate -v -f /etc/logrotate.d/mysql) but fails when run overnight by
> > cron.
> >
> > /var/log/mysqld.log {
> >   compress
> >   daily
> >   missingok
> >   notifempty
> >   rotate 3
> >   postrotate
> >     if test -x /usr/bin/mysqladmin && /usr/bin/mysqladmin ping
> &>/dev/null
> >     then
> >     /usr/bin/mysqladmin flush-logs
> >     fi
> >   endscript
> > }
> >
> > I tweaked it last night to capture the output of the mysqladmin command
> > and it did this:
> >
> > /usr/bin/mysqladmin: connect to server at 'localhost' failed
> > error: 'Access denied for user 'root'@'localhost' (using password: NO)'
> >
> > Which makes me think the problem is more about cron than MariaDB.
>
> No, MariaDB doesn't have a passwordless root user that mysqladmin needs
> to issue the flush-logs command.
>
> I suspect that there was originally a root user with socket
> authentication this system.
>
> Even after fixing this the mysqld may not be able to create new logs in
> /var/log/. I'd normally expect /var/log/mysql to be owned by the mysql
> user and its configuration to log the error to a file in this directory.
>
> >  I've
> > added some extra information gathering, so we'll see how it runs tonight.
> >
> >
> > On 27 March 2017 at 22:34, Daniel Black <daniel.black@xxxxxxxxxxx
> > <mailto:daniel.black@xxxxxxxxxxx>> wrote:
> >
> >     I think you'll find that the mysql user don't have permissions to
> create
> >     a new file in /var/log/. As such logrotate renames the file which is
> >     still open by mysqld. As such it is now writing to mysqld.log.1.
> >
> >     On 28/03/17 00:13, Matthew Pash wrote:
> >     > Hi,
> >     >
> >     > We've got some database servers running MariaDB 10.1.22, and are
> having
> >     > issues with logrotate.  Specifically, after it runs, it leaves a 0
> byte
> >     > file and continues writing log data to mysqld.log.1
> >     >
> >     > Manually running logrotate in verbose mode shows this error from
> >     > mysqladmin when it tries to run -flush_logs:
> >     >
> >     > /usr/bin/mysqladmin: flush failed; error: 'Unknown error'
> >     > error: error running non-shared postrotate script for
> >     > /var/log/mysqld.log of '/var/log/mysqld.log '
> >     > set default create context
> >
> >     What does the logrotate script look like? It really should be a
> "shared"
> >     (in a logrotate way) script.
> >
> >
> >
> >     > Has anyone seen this before?  It doesn't look like a permissions
> error -
> >     > the logs are created fine if you run systemctl restart mariadb.
> >
> >     Is the log actually writing to /var/log/mysqld.log using systemd? It
> >     normally writes to the journal because with systemd redirects stderr
> >     there
> >
> >
> > From lsof, it looks like /var/log/mysqld.log is being written to by the
> > mysql process itself:
> > $ sudo lsof | grep mysqld.log
> > mysqld    38803         mysql    1w      REG                8,3
> > 31781  537216904 /var/log/mysqld.log.1
> > mysqld    38803         mysql    2w      REG                8,3
> > 31781  537216904 /var/log/mysqld.log.1
> > ...
> >
> >
> >
> >
> >     > Thanks,
> >     > ~Matt
> >     >
> >     > --
> >     > *Matthew*
> >     > Senior Systems Administrator, IT Services
> >     > University of Bristol
> >     >
> >     >
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> >
> >
> >
> >
> > --
> > *Matthew Pash*
> > Senior Systems Administrator, IT Services
> > University of Bristol
>
>


-- 
*Matthew Pash*
Senior Systems Administrator, IT Services
University of Bristol