Red Hat Cluster Manager: Руководство по установке и администрированию Red Hat Cluster Manager
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Настройка службы MySQL

Служба MySQL предоставляет данные приложению базы данных, обеспечивая при этом высокую степень доступности. Приложение может в свою очередь предоставить сетевой доступ к базе данных клиентским системам, например Web-серверам. В случае отказа службы, приложение обращается к данным общей базы данных, используя другую кластерную систему. Доступной по сети службе базы данных обычно назначается IP адрес, который переносится вместе со службой, таким образом сохраняется прозрачное подключение клиентов к данным.

В приведенном ниже примере службы MySQL:

Пример сценария, запускающего и останавливающего сервер MySQL, приведенный ниже, расположен в файле /usr/share/cluster/doc/services/examples/mysql.server:

#!/bin/sh
# Copyright Abandoned 1996 TCX DataKonsult AB & Monty Program KB & Detron HB
# This file is public domain and comes with NO WARRANTY of any kind

# Mysql daemon start/stop script.

# Usually this is put in /etc/init.d (at least on machines SYSV R4
# based systems) and linked to /etc/rc3.d/S99mysql. When this is done
# the mysql server will be started when the machine is started.

# Comments to support chkconfig on RedHat Linux
# chkconfig: 2345 90 90
# description: A very fast and reliable SQL database engine.

PATH=/sbin:/usr/sbin:/bin:/usr/bin
basedir=/var/mysql
bindir=/var/mysql/bin
datadir=/var/mysql/var
pid_file=/var/mysql/var/mysqld.pid
mysql_daemon_user=root  # Run mysqld as this user.
export PATH

mode=$1

if test -w /             # determine if we should look at the root config file
then                     # or user config file
  conf=/etc/my.cnf
else
  conf=$HOME/.my.cnf    # Using the users config file
fi

# The following code tries to get the variables safe_mysqld needs from the
# config file.  This isn't perfect as this ignores groups, but it should
# work as the options doesn't conflict with anything else.

if test -f "$conf"       # Extract those fields we need from config file.
then
  if grep "^datadir" $conf > /dev/null
  then
    datadir=`grep "^datadir" $conf | cut -f 2 -d= | tr -d ' '`
  fi
  if grep "^user" $conf > /dev/null
  then
    mysql_daemon_user=`grep "^user" $conf | cut -f 2 -d= | tr -d ' ' | head -1`
  fi
  if grep "^pid-file" $conf > /dev/null
  then
    pid_file=`grep "^pid-file" $conf | cut -f 2 -d= | tr -d ' '`
  else
    if test -d "$datadir"
    then
      pid_file=$datadir/`hostname`.pid
    fi
  fi
  if grep "^basedir" $conf > /dev/null
  then
    basedir=`grep "^basedir" $conf | cut -f 2 -d= | tr -d ' '`
    bindir=$basedir/bin
  fi
  if grep "^bindir" $conf > /dev/null
  then
    bindir=`grep "^bindir" $conf | cut -f 2 -d=| tr -d ' '`
  fi
fi


# Safeguard (relative paths, core dumps..)
cd $basedir

case "$mode" in
  'start')
    # Start daemon

    if test -x $bindir/safe_mysqld
    then
      # Give extra arguments to mysqld with the my.cnf file. This script may
      # be overwritten at next upgrade.
      $bindir/safe_mysqld --user=$mysql_daemon_user --pid-file=$pid_file --datadir=$datadir &
    else
      echo "Can't execute $bindir/safe_mysqld"
    fi
    ;;

  'stop')
    # Stop daemon. We use a signal here to avoid having to know the
    # root password.
    if test -f "$pid_file"
    then
      mysqld_pid=`cat $pid_file`
      echo "Killing mysqld with pid $mysqld_pid"
      kill $mysqld_pid
      # mysqld should remove the pid_file when it exits.
    else
      echo "No mysqld pid file found. Looked for $pid_file."
    fi
    ;;

  *)
    # usage
    echo "usage: $0 start|stop"
    exit 1
    ;;
esac

В следующем примере показано, как с помощью cluadmin добавить службу MySQL.

cluadmin> service add

  The user interface will prompt you for information about the service.
  Not all information is required for all services.

  Enter a question mark (?) at a prompt to obtain help.

  Enter a colon (:) and a single-character command at a prompt to do
  one of the following:

  c - Cancel and return to the top-level cluadmin command
  r - Restart to the initial prompt while keeping previous responses
  p - Proceed with the next prompt
                                       
Currently defined services:

  databse1
  apache2
  dbase_home
  mp3_failover

Service name: mysql_1
Preferred member [None]: devel0
Relocate when the preferred member joins the cluster (yes/no/?) [no]: yes
User script (e.g., /usr/foo/script or None) [None]: \
	/etc/rc.d/init.d/mysql.server

Do you want to add an IP address to the service (yes/no/?): yes

        IP Address Information   

IP address: 10.1.16.12
Netmask (e.g. 255.255.255.0 or None) [None]: [Return]
Broadcast (e.g. X.Y.Z.255 or None) [None]: [Return]

Do you want to (a)dd, (m)odify, (d)elete or (s)how an IP address,
 or are you (f)inished adding IP addresses: f

Do you want to add a disk device to the service (yes/no/?): yes

        Disk Device Information

Device special file (e.g., /dev/sda1): /dev/sda1
Filesystem type (e.g., ext2, reiserfs, ext3 or None): ext2            
Mount point (e.g., /usr/mnt/service1 or None) [None]: /var/mysql
Mount options (e.g., rw, nosuid): rw
Forced unmount support (yes/no/?) [no]: yes

Do you want to (a)dd, (m)odify, (d)elete or (s)how devices, 
  or are you (f)inished adding device information: f

Disable service (yes/no/?) [no]: yes

name: mysql_1
disabled: yes
preferred node: devel0
relocate: yes
user script: /etc/rc.d/init.d/mysql.server
IP address 0: 10.1.16.12
  netmask 0: None
  broadcast 0: None
device 0: /dev/sda1
  mount point, device 0: /var/mysql
  mount fstype, device 0: ext2            
  mount options, device 0: rw
  force unmount, device 0: yes

Add mysql_1 service as shown? (yes/no/?) y
Added mysql_1.                              
cluadmin>
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