mysqld_safe脚本

 

 

#!/bin/sh // 脚本开头一定要以这么一行开头吗？// 这个脚本用于启动MySQL进程，如果它意外死亡，可以重新启动这个进程，如何做到，使用一个监听进程?起看门狗的作用?## This should be executed in the MySQL base directory if you are using a# binary installation that has other paths than you are using.## mysql.server works by first doing a cd to the base directory and from there# executing mysqld_safeKILL_MYSQLD=1;MYSQLD=trap '' 1 2 3 15 # we shouldn't let anyone kill usumask 007defaults=case "$1" in --no-defaults|--defaults-file=*|--defaults-extra-file=*) defaults="$1"; shift ;;esacusage () { cat <<EOFUsage: $0 [OPTIONS] --no-defaults Don't read the system defaults file --defaults-file=FILE Use the specified defaults file --defaults-extra-file=FILE Also use defaults from the specified file --ledir=DIRECTORY Look for mysqld in the specified directory --log-error=FILE Log errors to the specified log file --open-files-limit=LIMIT Limit the number of open files --core-file-size=LIMIT Limit core files to the specified size --timezone=TZ Set the system timezone --mysqld=FILE Use the specified file as mysqld --mysqld-version=VERSION Use "mysqld-VERSION" as mysqld --nice=NICE Set the scheduling priority of mysqld --skip-kill-mysqld Don't try to kill stray mysqld processesAll other options are passed to the mysqld program.EOF exit 1}parse_arguments() { # We only need to pass arguments through to the server if we don't # handle them here. So, we collect unrecognized options (passed on # the command line) into the args variable. pick_args= if test "$1" = PICK-ARGS-FROM-ARGV then pick_args=1 shift fi for arg do case "$arg" in --skip-kill-mysqld*) KILL_MYSQLD=0; ;; # these get passed explicitly to mysqld --basedir=*) MY_BASEDIR_VERSION=`echo "$arg" | sed -e "s;--basedir=;;"` ;; --datadir=*) DATADIR=`echo "$arg" | sed -e "s;--datadir=;;"` ;; --pid-file=*) pid_file=`echo "$arg" | sed -e "s;--pid-file=;;"` ;; --user=*) user=`echo "$arg" | sed -e "s;--[^=]*=;;"` ; SET_USER=1 ;; # these two might have been set in a [mysqld_safe] section of my.cnf # they are added to mysqld command line to override settings from my.cnf --socket=*) mysql_unix_port=`echo "$arg" | sed -e "s;--socket=;;"` ;; --port=*) mysql_tcp_port=`echo "$arg" | sed -e "s;--port=;;"` ;; # mysqld_safe-specific options - must be set in my.cnf ([mysqld_safe])! --ledir=*) ledir=`echo "$arg" | sed -e "s;--ledir=;;"` ;; --log-error=*) err_log=`echo "$arg" | sed -e "s;--log-error=;;"` ;; --open-files-limit=*) open_files=`echo "$arg" | sed -e "s;--open-files-limit=;;"` ;; --core-file-size=*) core_file_size=`echo "$arg" | sed -e "s;--core-file-size=;;"` ;; --timezone=*) TZ=`echo "$arg" | sed -e "s;--timezone=;;"` ; export TZ; ;; --mysqld=*) MYSQLD=`echo "$arg" | sed -e "s;--mysqld=;;"` ;; --mysqld-version=*) tmp=`echo "$arg" | sed -e "s;--mysqld-version=;;"` if test -n "$tmp" then MYSQLD="mysqld-$tmp" else MYSQLD="mysqld" fi ;; --nice=*) niceness=`echo "$arg" | sed -e "s;--nice=;;"` ;; --help) usage ;; *) if test -n "$pick_args" then # This sed command makes sure that any special chars are quoted, # so the arg gets passed exactly to the server. args="$args "`echo "$arg" | sed -e 's,/([^a-zA-Z0-9_.-]/),/////1,g'` fi ;; esac done}## First, try to find BASEDIR and ledir (where mysqld is)# MY_PWD=`pwd`# Check for the directories we would expect from a binary release installif test -f ./share/mysql/english/errmsg.sys -a -x ./bin/mysqldthen MY_BASEDIR_VERSION=$MY_PWD # Where bin, share and data are ledir=$MY_BASEDIR_VERSION/bin # Where mysqld is# Check for the directories we would expect from a source installelif test -f ./share/mysql/english/errmsg.sys -a / -x ./libexec/mysqldthen MY_BASEDIR_VERSION=$MY_PWD # Where libexec, share and var are ledir=$MY_BASEDIR_VERSION/libexec # Where mysqld is# Since we didn't find anything, used the compiled-in defaultselse MY_BASEDIR_VERSION=/usr ledir=/usr/libexecfi## Second, try to find the data directory## Try where the binary installs put itif test -d $MY_BASEDIR_VERSION/data/mysqlthen DATADIR=$MY_BASEDIR_VERSION/data if test -z "$defaults" -a -r "$DATADIR/my.cnf" then defaults="--defaults-extra-file=$DATADIR/my.cnf" fi# Next try where the source installs put itelif test -d $MY_BASEDIR_VERSION/var/mysqlthen DATADIR=$MY_BASEDIR_VERSION/var# Or just give up and use our compiled-in defaultelse DATADIR=/var/lib/mysqlfiif test -z "$MYSQL_HOME"then if test -r "$MY_BASEDIR_VERSION/my.cnf" && test -r "$DATADIR/my.cnf" then echo "WARNING: Found two instances of my.cnf -" echo "$MY_BASEDIR_VERSION/my.cnf and" echo "$DATADIR/my.cnf" echo "IGNORING $DATADIR/my.cnf" echo MYSQL_HOME=$MY_BASEDIR_VERSION elif test -r "$DATADIR/my.cnf" then echo "WARNING: Found $DATADIR/my.cnf" echo "Datadir is deprecated place for my.cnf, please move it to $MY_BASEDIR_VERSION" echo MYSQL_HOME=$DATADIR else MYSQL_HOME=$MY_BASEDIR_VERSION fifiexport MYSQL_HOMEuser=mysqlniceness=0# these rely on $DATADIR by default, so we'll set them later onpid_file=err_log=# Get first arguments from the my.cnf file, groups [mysqld] and [mysqld_safe]# and then merge with the command line argumentsif test -x ./bin/my_print_defaultsthen print_defaults="./bin/my_print_defaults"elif test -x /usr/bin/my_print_defaultsthen print_defaults="/usr/bin/my_print_defaults"elif test -x /usr/bin/mysql_print_defaultsthen print_defaults="/usr/bin/mysql_print_defaults"else print_defaults="my_print_defaults"fiargs=SET_USER=2parse_arguments `$print_defaults $defaults --loose-verbose mysqld server`if test $SET_USER -eq 2then SET_USER=0fiparse_arguments `$print_defaults $defaults --loose-verbose mysqld_safe safe_mysqld`parse_arguments PICK-ARGS-FROM-ARGV "$@"safe_mysql_unix_port=${mysql_unix_port:-${MYSQL_UNIX_PORT:-/var/lib/mysql/mysql.sock}}# Make sure that directory for $safe_mysql_unix_port existsmysql_unix_port_dir=`dirname $safe_mysql_unix_port`if [ ! -d $mysql_unix_port_dir ]then mkdir $mysql_unix_port_dir chown $user $mysql_unix_port_dir chmod 755 $mysql_unix_port_dirfi# Use the mysqld-max binary by default if the user doesn't specify a binaryif test -z "$MYSQLD"then if test -x $ledir/mysqld-max then MYSQLD=mysqld-max else MYSQLD=mysqld fifiif test ! -x $ledir/$MYSQLDthen echo "The file $ledir/$MYSQLD doesn't exist or is not executable" echo "Please do a cd to the mysql installation directory and restart" echo "this script from there as follows:" echo "./bin/mysqld_safe". echo "See http://dev.mysql.com/doc/mysql/en/mysqld_safe.html for more" echo "information" exit 1fiif test -z "$pid_file"then pid_file=$DATADIR/`/bin/hostname`.pidelse case "$pid_file" in /* ) ;; * ) pid_file="$DATADIR/$pid_file" ;; esacfitest -z "$err_log" && err_log=$DATADIR/`/bin/hostname`.errif test -n "$mysql_unix_port"then args="--socket=$mysql_unix_port $args"fiif test -n "$mysql_tcp_port"then args="--port=$mysql_tcp_port $args"fiif test $niceness -eq 0then NOHUP_NICENESS="nohup"else NOHUP_NICENESS="nohup nice -$niceness"fi# Using nice with no args to get the niceness level is GNU-specific.# This check could be extended for other operating systems (e.g.,# BSD could use "nohup sh -c 'ps -o nice -p $$' | tail -1").# But, it also seems that GNU nohup is the only one which messes# with the priority, so this is okay.if nohup nice > /dev/null 2>&1then normal_niceness=`nice` nohup_niceness=`nohup nice` numeric_nice_values=1 for val in $normal_niceness $nohup_niceness do case "$val" in -[0-9] | -[0-9][0-9] | -[0-9][0-9][0-9] | / [0-9] | [0-9][0-9] | [0-9][0-9][0-9] ) ;; * ) numeric_nice_values=0 ;; esac done if test $numeric_nice_values -eq 1 then nice_value_diff=`expr $nohup_niceness - $normal_niceness` if test $? -eq 0 && test $nice_value_diff -gt 0 && / nice --$nice_value_diff echo testing > /dev/null 2>&1 then # nohup increases the priority (bad), and we are permitted # to lower the priority with respect to the value the user # might have been given niceness=`expr $niceness - $nice_value_diff` NOHUP_NICENESS="nice -$niceness nohup" fi fielse if nohup echo testing > /dev/null 2>&1 then : else # nohup doesn't work on this system NOHUP_NICENESS="" fifiUSER_OPTION=""if test -w / -o "$USER" = "root"then if test "$user" != "root" -o $SET_USER = 1 then USER_OPTION="--user=$user" fi # If we are root, change the err log to the right user. touch $err_log; chown $user $err_log if test -n "$open_files" then ulimit -n $open_files args="--open-files-limit=$open_files $args" fifi# Try to set the core file size (even if we aren't root) because many systems# don't specify a hard limit on core file size.if test -n "$core_file_size"then ulimit -c $core_file_sizefi## If there exists an old pid file, check if the daemon is already running# Note: The switches to 'ps' may depend on your operating systemif test -f $pid_filethen PID=`cat $pid_file` if /bin/kill -0 $PID > /dev/null 2> /dev/null then if /bin/ps p $PID | grep -v grep | grep $MYSQLD > /dev/null then # The pid contains a mysqld process echo "A mysqld process already exists" echo "A mysqld process already exists at " `date` >> $err_log exit 1 fi fi rm -f $pid_file if test -f $pid_file then echo "Fatal error: Can't remove the pid file: $pid_file" echo "Fatal error: Can't remove the pid file: $pid_file at " `date` >> $err_log echo "Please remove it manually and start $0 again" echo "mysqld daemon not started" exit 1 fifi## Uncomment the following lines if you want all tables to be automatically# checked and repaired during startup. You should add sensible key_buffer# and sort_buffer values to my.cnf to improve check performance or require# less disk space.# Alternatively, you can start mysqld with the "myisam-recover" option. See# the manual for details.## echo "Checking tables in $DATADIR"# $MY_BASEDIR_VERSION/bin/myisamchk --silent --force --fast --medium-check $DATADIR/*/*.MYI# $MY_BASEDIR_VERSION/bin/isamchk --silent --force $DATADIR/*/*.ISMecho "Starting $MYSQLD daemon with databases from $DATADIR"# Does this work on all systems?#if type ulimit | grep "shell builtin" > /dev/null#then# ulimit -n 256 > /dev/null 2>&1 # Fix for BSD and FreeBSD systems#fiecho "`date +'%y%m%d %H:%M:%S mysqld started'`" >> $err_logwhile truedo rm -f $safe_mysql_unix_port $pid_file # Some extra safety if test -z "$args" then $NOHUP_NICENESS $ledir/$MYSQLD $defaults --basedir=$MY_BASEDIR_VERSION --datadir=$DATADIR $USER_OPTION --pid-file=$pid_file --skip-external-locking >> $err_log 2>&1 else eval "$NOHUP_NICENESS $ledir/$MYSQLD $defaults --basedir=$MY_BASEDIR_VERSION --datadir=$DATADIR $USER_OPTION --pid-file=$pid_file --skip-external-locking $args >> $err_log 2>&1" fi if test ! -f $pid_file # This is removed if normal shutdown then echo "STOPPING server from pid file $pid_file" break fi if true && test $KILL_MYSQLD -eq 1 then # Test if one process was hanging. # This is only a fix for Linux (running as base 3 mysqld processes) # but should work for the rest of the servers. # The only thing is ps x => redhat 5 gives warnings when using ps -x. # kill -9 is used or the process won't react on the kill. numofproces=`ps xaww | grep -v "grep" | grep "$ledir/$MYSQLD/>" | grep -c "pid-file=$pid_file"` echo -e "/nNumber of processes running now: $numofproces" | tee -a $err_log I=1 while test "$I" -le "$numofproces" do PROC=`ps xaww | grep "$ledir/$MYSQLD/>" | grep -v "grep" | grep "pid-file=$pid_file" | sed -n '$p'` for T in $PROC do break done # echo "TEST $I - $T **" if kill -9 $T then echo "$MYSQLD process hanging, pid $T - killed" | tee -a $err_log else break fi I=`expr $I + 1` done fi echo "`date +'%y%m%d %H:%M:%S'` mysqld restarted" | tee -a $err_logdoneecho "`date +'%y%m%d %H:%M:%S'` mysqld ended" | tee -a $err_logecho "" | tee -a $err_log