Incompatible upgrade - Is this workaround ok? (mysql-mmm)

[BJ Dierkes]

Hello all,

I maintain Multi-Master Replication Manager for MySQL in both Fedora and EPEL.  With
changes from 2.0.11 -> 2.1.0 there was an incompatible change in that the daemon
scripts were renamed:

mmmd_agent -> mmm_agentd
mmmd_mon -> mmm_mond


Upgrades obviously break because the INIT scripts and configuration files reference the
path to the files.  Would a sufficient work-around be a symlink to the old path, or would
that not be kosher for any reason?

Thank you for your feedback.

---
derks

[Stephen John Smoogen]

On Wed, Feb 24, 2010 at 11:36 AM, BJ Dierkes
<wdierkes(a)5dollarwhitebox.org&gt; wrote:
>  Hello all,
>
>  I maintain Multi-Master Replication Manager for MySQL in both Fedora and EPEL.  With
> changes from 2.0.11 -> 2.1.0 there was an incompatible change in that the daemon
> scripts were renamed:
>
>  mmmd_agent -> mmm_agentd
>  mmmd_mon -> mmm_mond
>  
I think this will need someone from Fedora packaging to comment versus
EPEL (as that would have precedence.) My un-educated opinion is that
there would not be a problem with symlinks if its for files. [Symlinks
for directories I think causes RPM heartburn somewhere but thats a
vague recollection.]

>  Upgrades obviously break because the INIT scripts and configuration
> files reference the path to the files.  Would a sufficient work-around be a symlink to the
> old path, or would that not be kosher for any reason?
>
>  Thank you for your feedback.
>
>  ---
>  derks
>
>
>
>  --
>  devel mailing list
>  devel(a)lists.fedoraproject.org
>  https://admin.fedoraproject.org/mailman/listinfo/devel
>  


-- 
Stephen J Smoogen.

Ah, but a man's reach should exceed his grasp. Or what's a heaven for?
-- Robert Browning

[Kevin Fenzi]

On Wed, 24 Feb 2010 12:36:31 -0600
BJ Dierkes <wdierkes(a)5dollarwhitebox.org&gt; wrote:

>  Hello all,
>  
>  I maintain Multi-Master Replication Manager for MySQL in both Fedora
>  and EPEL.  With changes from 2.0.11 -> 2.1.0 there was an
>  incompatible change in that the daemon scripts were renamed:
>  
>  mmmd_agent -> mmm_agentd
>  mmmd_mon -> mmm_mond
>  
>  
>  Upgrades obviously break because the INIT scripts and configuration
>  files reference the path to the files.  Would a sufficient
>  work-around be a symlink to the old path, or would that not be kosher
>  for any reason?
>  
>  Thank you for your feedback. 
Well, I would suggest if you can get it setup so it continues to work
as expected on upgrade it should be fine. If thats a symlink or
whatever it should be ok. 

Perhaps make and test a version, then post the spec diff for
comment/feedback if you like?

kevin

[BJ Dierkes]

On Feb 26, 2010, at 11:11 AM, Kevin Fenzi wrote:

>  On Wed, 24 Feb 2010 12:36:31 -0600
>  BJ Dierkes <wdierkes(a)5dollarwhitebox.org&gt; wrote:
>  
> > Hello all,
> > 
> > I maintain Multi-Master Replication Manager for MySQL in both Fedora
> > and EPEL.  With changes from 2.0.11 -> 2.1.0 there was an
> > incompatible change in that the daemon scripts were renamed:
> > 
> > mmmd_agent -> mmm_agentd
> > mmmd_mon -> mmm_mond
> > 
> > 
> > Upgrades obviously break because the INIT scripts and configuration
> > files reference the path to the files.  Would a sufficient
> > work-around be a symlink to the old path, or would that not be kosher
> > for any reason?
> > 
> > Thank you for your feedback.
>  
>  Well, I would suggest if you can get it setup so it continues to work
>  as expected on upgrade it should be fine. If thats a symlink or
>  whatever it should be ok. 
>  
>  Perhaps make and test a version, then post the spec diff for
>  comment/feedback if you like?
>  
>  kevin 

I have a working upgrade from mysql-mmm-2.0.x -> mysql-mmm-2.1.  I verified that all
expected changes happen, and that the running processes are gracefully condrestart'd.


The changes are pretty straight forward.  Because this is the first release of mysql-mmm
>= 2.1 I am touching a file at '%{_datadir}/mysql-mmm/.pre-2.1.0-upgrade-check'
in the install.  From %pre, if this file does *not* exist then the current install is <
2.1 (meaning modifications need to be done for 2.1 compatibility).  I then touch
'%{_localstatedir}/run/mysql-mmm/.post-2.1.0-upgrade-do_mods' (in %pre) allowing
me to verify that modifications are needed in %post.  

The modifications are simple sed changes for pid/status file and sbin daemon paths.  I
suppose I'm looking for another set of eyes to point out anything that is not obvious
to me.  The following are the [snipped] spec changes:

# --------------------------------------------------
%install
# … snipped
# Specific for upgrading from 2.0.x -> 2.1
touch %{buildroot}%{_datadir}/mysql-mmm/.pre-2.1.0-upgrade-check-do-not-delete


%pre
# This is to facilitate the upgradability of 2.0.x -> 2.1
DO_MOD_CHECK="%{_datadir}/mysql-mmm/.pre-2.1.0-upgrade-check-do-not-delete"
DO_MOD_VERIFY="%{_localstatedir}/run/mysql-mmm/.post-2.1.0-upgrade-do_mods"

rm -f $DO_MOD_VERIFY 2>/dev/null

if [ ! -f "$DO_MOD_CHECK" ]; then
    # the 'check' file does *not* exist (only installed as of 2.1.0)
    # modifications are necessary.
    touch $DO_MOD_VERIFY

    # copy paths for new configs (if replaced on upgrade)
    cp -a %{_localstatedir}/run/mysql-mmm/mmmd_mon.pid \
      %{_localstatedir}/run/mysql-mmm/mmm_mond.pid 2>/dev/null ||:
    cp -a %{_localstatedir}/lib/mysql-mmm/mmmd_mon.status \
      %{_localstatedir}/lib/mysql-mmm/mmm_mond.status 2>/dev/null ||:
    cp -a %{_localstatedir}/run/mysql-mmm/mmmd_agent.pid \
      %{_localstatedir}/run/mysql-mmm/mmm_agentd.pid 2>/dev/null ||:
fi


%post
# This is to facilitate the upgradability of 2.0.x -> 2.1
DO_MOD_VERIFY="%{_localstatedir}/run/mysql-mmm/.post-2.1.0-upgrade-do_mods"

if [ -f "$DO_MOD_VERIFY" ]; then
    # system was upgraded from < 2.1, need to modify config files/paths
    if [ -f %{_sysconfdir}/mysql-mmm/mmm_mon.conf ]; then
        cp -a %{_sysconfdir}/mysql-mmm/mmm_mon.conf
%{_sysconfdir}/mysql-mmm/mmm_mon.conf-pre2.1
        sed -i
"s|/var/run/mysql-mmm/mmmd_mon.pid|/var/run/mysql-mmm/mmm_mond.pid|g" \
               %{_sysconfdir}/mysql-mmm/mmm_mon.conf
        sed -i
"s|/var/lib/mysql-mmm/mmmd_mon.status|/var/lib/mysql-mmm/mmm_mond.status|g" \
               %{_sysconfdir}/mysql-mmm/mmm_mon.conf
    fi
    if [ -f %{_sysconfdir}/mysql-mmm/mmm_common.conf ]; then
        cp -a %{_sysconfdir}/mysql-mmm/mmm_common.conf
%{_sysconfdir}/mysql-mmm/mmm_common.conf-pre2.1
        sed -i
"s|/var/run/mysql-mmm/mmmd_agent.pid|/var/run/mysql-mmm/mmm_agentd.pid|g" \
               %{_sysconfdir}/mysql-mmm/mmm_common.conf
    fi
fi


%post agent
# … snipped
# This is to facilitate the upgradability of 2.0.x -> 2.1
DO_MOD_VERIFY="%{_localstatedir}/run/mysql-mmm/.post-2.1.0-upgrade-do_mods"
if [ -f "$DO_MOD_VERIFY" ]; then
    # remove old files
    rm -f %{_localstatedir}/run/mysql-mmm/mmmd_agent.pid 2>/dev/null ||:
fi


%post monitor
# … snipped
# This is to facilitate the upgradability of 2.0.x -> 2.1
DO_MOD_VERIFY="%{_localstatedir}/run/mysql-mmm/.post-2.1.0-upgrade-do_mods"
if [ -f "$DO_MOD_VERIFY" ]; then
    # remove old files
    rm -f %{_localstatedir}/run/mysql-mmm/mmmd_mon.pid 2>/dev/null ||:
    rm -f %{_localstatedir}/lib/mysql-mmm/mmmd_mon.status 2>/dev/null ||:
fi
# --------------------------------------------------


Thanks.

---
derks