Mysql mysql.server启动脚本详解 .-白红宇

Mysql mysql.server启动脚本详解 .

阅读量：5997 次

发布时间：2019-06-20

本文共 9377 字，大约阅读时间需要 31 分钟。

#1.变量初始化

#--------------------------------------------------------------------------------------------------------------------------------

basedir=

datadir=

service_startup_timeout=900

pid_file=

server_pid_file=

use_mysqld_safe=1

user=mysql

if test -z "$basedir"

then

basedir=/usr/local/mysql

bindir=./bin

if test -z "$datadir"

then

datadir=/usr/local/mysql/data

sbindir=./bin

libexecdir=./bin

else

bindir="$basedir/bin"

if test -z "$datadir"

then

datadir="$basedir/data"

sbindir="$basedir/sbin"

libexecdir="$basedir/libexec"

datadir_set=

#-----------------------------------------------------------------------------------------------------------------------

#2.函数定义

#--------------------------------------------------------------------------------------------------------------------------

lsb_functions="/lib/lsb/init-functions #" 这是一个linux系统脚本，包含一些打印log函数"

if test -f $lsb_functions ; then

. $lsb_functions #如果存在改文件，将这些函数导入到该脚本，使其可以使用

else #否则自定义函数

log_success_msg()

{

echo " SUCCESS! $@"

}

log_failure_msg()

{

echo " ERROR! $@"

}

PATH=/sbin:/usr/sbin:/bin:/usr/bin:$basedir/bin

export PATH

mode=$1 # start or stop mysql.server 脚本的输入参数

shift 将$1删除

other_args="$*" 将$2,... $n 赋值给other_args

#系统对echo c 和 echo -n 的结果

#--------------------------------------------------------------

case `echo "testing\c"`,`echo -n testing` in

*c*,-n*) echo_n= echo_c= ;;

*c*,*) echo_n=-n echo_c= ;;

*) echo_n= echo_c='\c' ;;

esac

#-------------------------------------------------------

#该函数将my_print_defaults 命令分析出得参数赋值给相应的变量

#----------------------------------------------------------------------

parse_server_arguments() {

for arg do

case "$arg" in

--basedir=*) basedir=`echo "$arg" | sed -e 's/^[^=]*=//'`

bindir="$basedir/bin"

if test -z "$datadir_set"; then

datadir="$basedir/data"

sbindir="$basedir/sbin"

libexecdir="$basedir/libexec"

;;

--datadir=*) datadir=`echo "$arg" | sed -e 's/^[^=]*=//'`

datadir_set=1

;;

--user=*) user=`echo "$arg" | sed -e 's/^[^=]*=//'` ;;

--pid-file=*) server_pid_file=`echo "$arg" | sed -e 's/^[^=]*=//'` ;;

--service-startup-timeout=*) service_startup_timeout=`echo "$arg" | sed -e 's/^[^=]*=//'` ;;

--use-mysqld_safe) use_mysqld_safe=1;;

--use-manager) use_mysqld_safe=0;;

esac

done

}

#---------------------------------------------------------------------

#该函数用于my_print_defaults 命令分析出的参数赋值给相应的变量

parse_manager_arguments() {

for arg do

case "$arg" in

--pid-file=*) pid_file=`echo "$arg" | sed -e 's/^[^=]*=//'` ;;

--user=*) user=`echo "$arg" | sed -e 's/^[^=]*=//'` ;;

esac

done

}

#该函数在启动和停止mysql服务时用于等待pid的生成

#-------------------------------------------------------------------------------

wait_for_pid () {

verb="$1"

manager_pid="$2" # process ID of the program operating on the pid-file

i=0

avoid_race_condition="by checking again"

while test $i -ne $service_startup_timeout ; do

case "$verb" in

'created')

# wait for a PID-file to pop into existence.

test -s $pid_file && i='' && break

;;

'removed')

# wait for this PID-file to disappear

test ! -s $pid_file && i='' && break

;;

echo "wait_for_pid () usage: wait_for_pid created|removed manager_pid"

exit 1

;;

esac

# if manager isn't running, then pid-file will never be updated

if test -n "$manager_pid"; then

if kill -0 "$manager_pid" 2>/dev/null; then

: # the manager still runs

else

# The manager may have exited between the last pid-file check and now.

if test -n "$avoid_race_condition"; then

avoid_race_condition=""

continue # Check again.

# there's nothing that will affect the file.

log_failure_msg "Manager of pid-file quit without updating file."

return 1 # not waiting any more.

echo $echo_n ".$echo_c"

i=`expr $i + 1`

sleep 1

done

if test -z "$i" ; then

log_success_msg

return 0

else

log_failure_msg

return 1

}

#--------------------------------------------------------------------------------------------

#3 指定my_print_defaults命令的路径

#---------------------------------------------------------------------------------------

if test -x ./bin/my_print_defaults #这个命令主要用来分析my.cnf的参数使用方法 my_print_defaults -e my.cnf mysqld (指的配置文件中[mysqld]下的内容)

then

print_defaults="./bin/my_print_defaults"

elif test -x $bindir/my_print_defaults

then

print_defaults="$bindir/my_print_defaults"

elif test -x $bindir/mysql_print_defaults

then

print_defaults="$bindir/mysql_print_defaults"

else

# Try to find basedir in /etc/my.cnf

conf=/etc/my.cnf

print_defaults=

if test -r $conf

then

subpat='^[^=]*basedir[^=]*=$.*$$'

dirs=`sed -e "/$subpat/!d" -e 's//\1/' $conf`

for d in $dirs

d=`echo $d | sed -e 's/[ ]//g'`

if test -x "$d/bin/my_print_defaults"

then

print_defaults="$d/bin/my_print_defaults"

break

if test -x "$d/bin/mysql_print_defaults"

then

print_defaults="$d/bin/mysql_print_defaults"

break

done

# Hope it's in the PATH ... but I doubt it

test -z "$print_defaults" && print_defaults="my_print_defaults"

#----------------------------------------------------------------------------------------------------------

#4 指定配置文件路径

#---------------------------------------------------------------------------------------------------------

extra_args=""

if test -r "$basedir/my.cnf"

then

extra_args="-e $basedir/my.cnf"

else

if test -r "$datadir/my.cnf"

then

extra_args="-e $datadir/my.cnf"

#-----------------------------------------------------------------------------------------------------------

#使用parse_server_arguments, parse_manager_arguments 函数和my_print_defaults 从my.cnf 中获取相应的参数并付给相应的变量

parse_server_arguments `$print_defaults $extra_args mysqld server mysql_server mysql.server`

parse_manager_arguments `$print_defaults $extra_args manager`

#-----------------------------------------------------------------------------

指定mysqlmanager 启动时的pid_file的位置和 mysql_safe启动时pid_file 的位置

if test -z "$pid_file"

then

pid_file=$datadir/mysqlmanager-`/bin/hostname`.pid

else

case "$pid_file" in

/* ) ;;

* ) pid_file="$datadir/$pid_file" ;;

esac

if test -z "$server_pid_file"

then

server_pid_file=$datadir/`/bin/hostname`.pid

else

case "$server_pid_file" in

/* ) ;;

* ) server_pid_file="$datadir/$server_pid_file" ;;

esac

#-------------------------------------------------------------------------------

启动和停止mysql server 的主体程序

case "$mode" in

'start') #开始启动服务

cd $basedir

#---------

#指定mysqlmanager的位置

manager=$bindir/mysqlmanager

if test -x $libexecdir/mysqlmanager

then

manager=$libexecdir/mysqlmanager

elif test -x $sbindir/mysqlmanager

then

manager=$sbindir/mysqlmanager

#------------

echo $echo_n "Starting MySQL"

if test -x $manager -a "$use_mysqld_safe" = "0" # 当use_mysqld_safe=0，这个参数从my.cnf中取得，使用mysqlmanager 启动mysql

then

if test -n "$other_args";then #mysqlmanager 启动不支持有其他的参数，仅仅支持start参数,如果有其他参数则退出

log_failure_msg "MySQL manager does not support options '$other_args'"

exit 1

# Give extra arguments to mysqld with the my.cnf file. This script may

# be overwritten at next upgrade.

$manager --user=$user --pid-file=$pid_file >/dev/null 2>&1 & 启动mysql

wait_for_pid created $!; return_value=$? #

wait_for_pid created 等待mysqlserver的启动

# Make lock for RedHat / SuSE

if test -w /var/lock/subsys

then

touch /var/lock/subsys/mysqlmanager #

然后创建系统服务锁：/var/lock/subsys/mysqlmanager

exit $return_value

elif test -x $bindir/mysqld_safe #使用mysqld_safe启动mysql

then

pid_file=$server_pid_file

$bindir/mysqld_safe --datadir=$datadir --pid-file=$server_pid_file $other_args >/dev/null 2>&1 &

wait_for_pid created $!; return_value=$? #

wait_for_pid created 等待mysqlserver的启动

if test -w /var/lock/subsys

then

touch /var/lock/subsys/mysql #

然后创建系统服务锁：/var/lock/subsys/mysql

exit $return_value

else

log_failure_msg "Couldn't find MySQL manager ($manager) or server ($bindir/mysqld_safe)"

;;

'stop') 关闭mysql服务

lock_dir=/var/lock/subsys/mysqlmanager

if test ! -s "$pid_file"

then

pid_file=$server_pid_file

lock_dir=/var/lock/subsys/mysql

if test -s "$pid_file"

then

mysqlmanager_pid=`cat $pid_file`

echo $echo_n "Shutting down MySQL"

kill $mysqlmanager_pid

wait_for_pid removed "$mysqlmanager_pid"; return_value=$?

if test -f $lock_dir

then

rm -f $lock_dir

exit $return_value

else

log_failure_msg "MySQL manager or server PID file could not be found!"

;;

'restart')

if $0 stop $other_args; then

$0 start $other_args

else

log_failure_msg "Failed to stop running server, so refusing to try to start."

exit 1

;;

'reload'|'force-reload')

if test -s "$server_pid_file" ; then

read mysqld_pid < $server_pid_file

kill -HUP $mysqld_pid && log_success_msg "Reloading service MySQL"

touch $server_pid_file

else

log_failure_msg "MySQL PID file could not be found!"

exit 1

;;

'status')

if test -s "$server_pid_file" ; then

read mysqld_pid < $server_pid_file

if kill -0 $mysqld_pid 2>/dev/null ; then

log_success_msg "MySQL running ($mysqld_pid)"

exit 0

else

log_failure_msg "MySQL is not running, but PID file exists"

exit 1

else

# Try to find appropriate mysqld process

mysqld_pid=`pidof $sbindir/mysqld`

if test -z $mysqld_pid ; then

if test "$use_mysqld_safe" = "0" ; then

lockfile=/var/lock/subsys/mysqlmanager

else

lockfile=/var/lock/subsys/mysql

if test -f $lockfile ; then

log_failure_msg "MySQL is not running, but lock exists"

exit 2

log_failure_msg "MySQL is not running"

exit 3

else

log_failure_msg "MySQL is running but PID file could not be found"

exit 4

;;

# usage

echo "Usage: $0 {start|stop|restart|reload|force-reload|status} [ MySQL server options ]"

exit 1

;;

esac

exit 0

转载于:https://blog.51cto.com/zorro/1093979

你可能感兴趣的文章

JAVA常见面试题之Forward和Redirect的区别

查看>>

网站目录文件权限的简单安全设置

查看>>

iReport中使用JavaBeanDataSource，父子报表，html标签，自定义格...

Linux无法登录，提示module is unknown并闪退

查看>>

Calendar 日期类的使用

查看>>

Zookeeper-Watcher机制与异步调用原理

查看>>

RAID详解[RAID0/RAID1/RAID10/RAID5]

查看>>

解决ADT大量出现"Unexpected value from nativeGetEnabledTa

Android listview与adapter用法(BaseAdapter + getView)

查看>>

ViewPager + Fragment实现滑动标签页

TiDB 2.1 GA Release Notes

查看>>