RPMs wrongly assumes that .pid file is always located in datadir

[Valerii Kravchuk]

The preinstall scriptlet looks up the datadir via:

mysql_datadir=`/usr/bin/my_print_defaults server mysqld | grep '^--datadir=' | sed -n 's/--datadir=//p'`

and then assumes that the server is currently running if one file exists matching:

NR_PID_FILES=`ls $mysql_datadir/*.pid 2>/dev/null | wc -l`

This only works if the PID file is located in that directory, though, and it may not be the case if explicit pid-file setting is used.

As a result, during installation of RPMs wrong assumption may be made about server running or not.

[Valerii Kravchuk (valerii-kravchuk)]

This is easy to verify by code review actually:

openxs@debian7:~/bzr/percona-5.5$ bzr version-info
revision-id: <email address hidden>
date: 2013-07-12 09:17:29 +0000
build-date: 2013-07-16 20:07:15 +0300
revno: 555
branch-nick: percona-5.5
openxs@debian7:~/bzr/percona-5.5$ grep -n NR_PID_FILES build/percona-server.spec
653:NR_PID_FILES=`ls $mysql_datadir/*.pid 2>/dev/null | wc -l`
654:case $NR_PID_FILES in
openxs@debian7:~/bzr/percona-5.5$ cd ../percona-5.6
openxs@debian7:~/bzr/percona-5.6$ grep -n NR_PID_FILES build/percona-server.spec
645:NR_PID_FILES=`ls $mysql_datadir/*.pid 2>/dev/null | wc -l`
646:case $NR_PID_FILES in
openxs@debian7:~/bzr/percona-5.6$ bzr version-info revision-id: <email address hidden>
date: 2013-07-12 09:09:16 +0000
build-date: 2013-07-16 20:10:41 +0300
revno: 405
branch-nick: percona-5.6

[Valerii Kravchuk (valerii-kravchuk)]

In 5.1 we do not try to be smart...

[Scott Dellinger (scott-dellinger)]

I filed the support request leading to this bug, and would love to see this resolved so that my cf-engine package updates stop leading to database services that aren't running. :-) A fix for this issue could be simply to obtain the PID file location in the package preinstall scriptlet via something like:

     pid_file=`/usr/bin/my_print_defaults mysqld | grep '^--pid-file=' | sed -n 's/--pid-file=//p'`

and then replace the line:

    NR_PID_FILES=`ls $mysql_datadir/*.pid 2>/dev/null | wc -l`

with

    NR_PID_FILES=`ls $pid_file 2>/dev/null | wc -l`

leaving everything else alone. This would correctly locate the PID file, if it exists, regardless of configured location.

[Roel Van de Paar (roel11)]

The fix in #3 does not account for # mysqld's running on one box, as for instance a hosting service would do.

Thinking out loud (without code review):
ps -ef | grep "mysqld" | grep -v "grep" | awk '{print $2}' | sort -u | wc -l
would at least give correct total number of running instances?

[Tomislav Plavcic (tplavcic)]

More suggestions at bug https://bugs.launchpad.net/percona-server/+bug/1311840

[monty solomon (monty+launchpad)]

I suggest that Percona track changes to the upstream RPM scripts and migrate the changes into the Percona scripts.

There are other bugs here that were caused by stale scripts.

Thanks.

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-694