diff options
Diffstat (limited to 'sql/watchdog_mysqld')
-rwxr-xr-x | sql/watchdog_mysqld | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/sql/watchdog_mysqld b/sql/watchdog_mysqld new file mode 100755 index 00000000000..0b26bb15acd --- /dev/null +++ b/sql/watchdog_mysqld @@ -0,0 +1,126 @@ +#!/usr/bin/perl +# Copyright (C) 1979-1998 TcX AB & Monty Program KB & Detron HB +# +# This software is distributed with NO WARRANTY OF ANY KIND. No author or +# distributor accepts any responsibility for the consequences of using it, or +# for whether it serves any particular purpose or works at all, unless he or +# she says so in writing. Refer to the Free Public License (the "License") +# for full details. +# +# Every copy of this file must include a copy of the License, normally in a +# plain ASCII text file named PUBLIC. The License grants you the right to +# copy, modify and redistribute this file, but only under certain conditions +# described in the License. Among other things, the License requires that +# the copyright notice and this notice be preserved on all copies. */ + +# +# This scripts is started by safe_mysqld. It checks that MySQL is alive and +# working ( = answering to ping). If not, force mysqld down, check all +# tables and let safe_mysqld restart the server. +# +# For this to work, you should have procmail installed as the commands +# 'lockfile' and is used to sync with safe_mysqld +# +# NOTE: You should only use this script as a last resort if mysqld locks +# up unexpectedly in a critical application and you have to get it to +# work temporarily while waiting for a solution from mysql@tcx.se or +# mysql-support@tcx.se + + +use POSIX "waitpid"; + +# Arguments from safe_mysqld + +if ($#ARGV != 4) +{ + print "$0: Wrong number of arguments. Aborting\n"; + exit 1; +} + +$lock_file=shift; # File to lock to sync with safe_mysqld +$pid_file=shift; # Pid file used by mysqld +$bin_dir=shift; # Directory where mysqladmin is +$test_timeout=shift; # Time between testing if mysqld is alive +$wait_timeout=shift; # How long time to wait for ping + +$|=1; # autoflush + +# Check that mysqld has started properly + +for ($i=1 ; $i < 10 ; $i ++) +{ + last if (-e $pid_file); +} +sleep(1); # If server has just created the file +if (($mysqld_pid=`cat $pid_file`) <= 0) +{ + print "$0: Error: Invalid pidfile (contains '$mysqld_pid'). Aborting\n"; +} + +# Start pinging mysqld + +for (;;) +{ + sleep($test_timeout); # Time between tests + `lockfile $lock_file > /dev/null 2>&1`; # Sync with safe_mysqld + if (($pid=fork()) == 0) + { + setpgrp(0,0); + exit(int(system("$bin_dir/mysqladmin -w status > /dev/null")/256)); + } + for ($i=0; ($res=waitpid(-1,&POSIX::WNOHANG)) == 0 && $i < $wait_timeout ; $i++) + { + sleep(1); + } + if ($res == 0) + { + print "$0: Warning: mysqld hanged; Killing it so that safe_mysqld can restart it!\n"; + $mysqld_pid= `cat $pid_file`; + if ($mysqld_pid <= 0) + { + print "$0: Error: Invalid pidfile (contains '$mysqld_pid'). Aborting\n"; + system("rm -f $lock_file"); + kill(-9,$pid); + exit 1; + } + print "$0: Sending signal 15 to $mysqld_pid\n"; + kill(-15, $pid,$mysqld_pid); # Give it a last change to die nicely + for ($i=0 ; $i < 5 ; $i++) { sleep(1); } # Wait 5 seconds (signal safe) + waitpid(-1,&POSIX::WNOHANG); + if (kill(0,$pid,$mysqld_pid) != 0) + { + print "$0: Sending signal 9 to $mysqld_pid\n"; + kill(-9,$pid,$mysqld_pid); # No time to be nice anymore + sleep(2); # Give system time to clean up + waitpid(-1,&POSIX::WNOHANG); + if (kill(0,$mysqld_pid) != 0) + { + print "$0: Warning: mysqld don't want to die. Aborting\n"; + system("rm -f $lock_file"); + exit 1; + } + } + # safe_mysqld will not restart mysqld if the pid file doesn't exists + system("rm $pid_file"); + system("touch $pid_file"); + } + elsif ($res == -1) + { + print "$0: Error: waitpid returned $res when wating for pid $pid\nPlease verify that $0 is correct for your system\n"; + system("rm -f $lock_file"); + exit 1; + } + else + { + $exit_code=int($?/256); + if ($exit_code != 0) + { + print "$0: Warning: mysqladmin returned exit code $exit_code\n"; + } + else + { + #print "mysqld is alive and feeling well\n"; + } + } + system("rm -f $lock_file"); # safemysqld will now take over +} |