概述

本次的文章會格外的長，網上大多的設定流程已經不可使用，本篇文章可以稱為保姆級教學，而且通過shell指令碼大大減少了部署mysql主從，雙主的工作量。

如上圖，VIP地址為192.168.10.100，如果主機192.168.10.129掛了，會自動切換到備機192.168.10.130上，由於是雙主，資料可以進行同步恢復

部署流程大致為

在192.168.10.129伺服器上部署docker、mysql一主一叢
在192.168.10.130伺服器上部署docker、mysql一主一叢
192.168.10.129的Master1資料庫和192.168.10.130的資料庫互為主從
在兩臺伺服器上安裝keeplived形成高可用

部署流程

設定第一臺Master

部署Master

準備Master組態檔my.cnf

mkdir /home/mysql_config
mkdir /home/mysql_config/master1
mkdir /home/mysql_config/master1/config
touch /home/mysql_config/master1/config/my.cnf
chmod +x /home/mysql_config/master1/config/my.cnf

cat > /home/mysql_config/master1/config/my.cnf <<EOF
[mysqld]
server_id=110
user=mysql
character-set-server=utf8mb4
collation-server=utf8mb4_general_ci
default-authentication-plugin=mysql_native_password
max_connections=800
max_connect_errors=1000

log_bin=mysql_binlog_master1
slow_query_log=ON
slow_query_log_file=/var/lib/mysql/slow.log

log_error=/var/lib/mysql/mysql.err
log_replica_updates=ON
enforce_gtid_consistency=ON
gtid_mode=ON

plugin-load="rpl_semi_sync_source=semisync_source.so;rpl_semi_sync_replica=semisync_replica.so"
#rpl_semi_sync_source_enabled=ON
#rpl_semi_sync_replica_enabled=ON

binlog-ignore-db=information_schema
binlog-ignore-db=mysql
binlog-ignore-db=sys
binlog-ignore-db=performance_schema

[client]
default-character-set=utf8mb4
EOF

執行Master

會自動下載最新版mysql

docker run -d --name mysql_master1 -p 3306:3306 -e MYSQL_ROOT_PASSWORD=admin123456 -e TZ="Asia/Shanghai" -v /home/mysql_config/master1/config:/etc/mysql/conf.d mysql --authentication_policy=mysql_native_password

啟動半同步外掛

此步主要是為了將#rpl_semi_sync_source_enabled=ON和#rpl_semi_sync_replica_enabled=ON的井號去掉

mysql會檢測semisync_source.so和semisync_replica.so外掛的情況，如果沒有安裝就不能設定rpl_semi_sync_source_enabled和rpl_semi_sync_replica_enabled

cat > /home/mysql_config/master1/config/my.cnf <<EOF
[mysqld]
server_id=110
user=mysql
character-set-server=utf8mb4
collation-server=utf8mb4_general_ci
default-authentication-plugin=mysql_native_password
max_connections=800
max_connect_errors=1000

log_bin=mysql_binlog_master1
slow_query_log=ON
slow_query_log_file=/var/lib/mysql/slow.log

log_error=/var/lib/mysql/mysql.err
log_replica_updates=ON
enforce_gtid_consistency=ON
gtid_mode=ON

plugin-load="rpl_semi_sync_source=semisync_source.so;rpl_semi_sync_replica=semisync_replica.so"
rpl_semi_sync_source_enabled=ON
rpl_semi_sync_replica_enabled=ON

binlog-ignore-db=information_schema
binlog-ignore-db=mysql
binlog-ignore-db=sys
binlog-ignore-db=performance_schema

[client]
default-character-set=utf8mb4
EOF

重新開啟

docker restart mysql_master1
docker exec -it mysql_master1 mysql -uroot -padmin123456 -e "show variables like 'rpl_semi_sync_%';"
+---------------------------------------------+------------+
| Variable_name                               | Value      |
+---------------------------------------------+------------+
| rpl_semi_sync_replica_enabled               | ON         |
| rpl_semi_sync_replica_trace_level           | 32         |
| rpl_semi_sync_source_enabled                | ON         |
| rpl_semi_sync_source_timeout                | 10000      |
| rpl_semi_sync_source_trace_level            | 32         |
| rpl_semi_sync_source_wait_for_replica_count | 1          |
| rpl_semi_sync_source_wait_no_replica        | ON         |
| rpl_semi_sync_source_wait_point             | AFTER_SYNC |
+---------------------------------------------+------------+

部署Slave

準備Slave組態檔my.cnf

mkdir /home/mysql_config/slave1
mkdir /home/mysql_config/slave1/config
touch /home/mysql_config/slave1/config/my.cnf
chmod +x /home/mysql_config/slave1/config/my.cnf

cat > /home/mysql_config/slave1/config/my.cnf <<EOF
[mysqld]
server_id=120
user=mysql
character-set-server=utf8mb4
collation-server=utf8mb4_general_ci
default-authentication-plugin=mysql_native_password
max_connections=800
max_connect_errors=1000

log_bin=mysql_binlog_master1_slave1
slow_query_log=ON
slow_query_log_file=/var/lib/mysql/slow.log

log_error=/var/lib/mysql/mysql.err
log_replica_updates=ON     
enforce_gtid_consistency=ON
gtid_mode=ON

binlog-ignore-db=information_schema
binlog-ignore-db=mysql
binlog-ignore-db=sys
binlog-ignore-db=performance_schema

[client]
default-character-set=utf8mb4
EOF

執行Slave

會自動下載最新版mysql

docker run -d --name mysql_master1_slave1 -p 4306:3306 -e MYSQL_ROOT_PASSWORD=admin123456 -e TZ="Asia/Shanghai" -v /home/mysql_config/slave1/config:/etc/mysql/conf.d mysql --authentication_policy=mysql_native_password

主從設定

安裝MySQL使用者端

兩臺Master都需要安裝，而且後續keepalived也需要安裝

在網站查詢https://dev.mysql.com/downloads/repo/yum/要安裝的mysql版本，以mysql80-community-release-el8-4.noarch.rpm舉例

yum module disable mysql
wget https://dev.mysql.com/get/mysql80-community-release-el8-4.noarch.rpm
rpm -ivh mysql80-community-release-el8-4.noarch.rpm
yum install mysql-community-client
yum module enable mysql

編寫指令碼檔案

touch /home/mysql_config/mysql_script.sh
chmod +x /home/mysql_config/mysql_script.sh

cat > /home/mysql_config/mysql_script.sh <<'EOF'
#!/bin/bash
MASTER_RPL_USER=rpl_admin
MASTER_RPL_PASSWORD=rpl_admin123456
# master and slaves admin user
ADMIN_USER=root
ADMIN_PASSWORD=admin123456
ALLOW_HOST=%

MASTER_HOST=192.168.10.129
MASTER_PORT=3306
SLAVE_HOST=192.168.10.129
SLAVE_PORT=4306

# master
DROP_USER_SQL="DROP USER '$MASTER_RPL_USER'@'$ALLOW_HOST';"
CREATE_USER_SQL="CREATE USER '$MASTER_RPL_USER'@'$ALLOW_HOST' IDENTIFIED BY '$MASTER_RPL_PASSWORD';"
GRANT_PRIVILEGES_SQL="GRANT REPLICATION SLAVE ON *.* TO '$MASTER_RPL_USER'@'$ALLOW_HOST';"
FLUSH_PRIVILEGES_SQL="FLUSH PRIVILEGES;"

mysql -h$MASTER_HOST -P$MASTER_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e "$CREATE_USER_SQL"
mysql -h$MASTER_HOST -P$MASTER_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e "$GRANT_PRIVILEGES_SQL"
mysql -h$MASTER_HOST -P$MASTER_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e "$FLUSH_PRIVILEGES_SQL"

# master's slave shell
RESULT=`mysql -h$MASTER_HOST -p$MASTER_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e "SHOW MASTER STATUS;" | grep -v grep |tail -n +2| awk '{print $1,$2}'`
LOG_FILE_NAME=`echo $RESULT | grep -v grep | awk '{print $1}'`
LOG_FILE_POS=`echo $RESULT | grep -v grep | awk '{print $2}'`

SYNC_SQL="change master to master_host='$MASTER_HOST', master_port=$MASTER_PORT, master_user='$MASTER_RPL_USER',master_password='$MASTER_RPL_PASSWORD',master_log_file='$LOG_FILE_NAME',master_log_pos=$LOG_FILE_POS;"
START_SYNC_SQL="start REPLICA;"
STATUS_SQL="show REPLICA status\G;"

mysql -h$SLAVE_HOST -P$SLAVE_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$SYNC_SQL"
mysql -h$SLAVE_HOST -P$SLAVE_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$START_SYNC_SQL"
mysql -h$SLAVE_HOST -P$SLAVE_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$STATUS_SQL"
EOF

執行指令碼並檢查

sh /home/mysql_config/mysql_script.sh
*************************** 1. row ***************************
...
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
...

設定第二臺

部署Master

準備Master組態檔my.cnf

mkdir /home/mysql_config
mkdir /home/mysql_config/master2
mkdir /home/mysql_config/master2/config
touch /home/mysql_config/master2/config/my.cnf
chmod +x /home/mysql_config/master2/config/my.cnf

cat > /home/mysql_config/master2/config/my.cnf <<EOF
[mysqld]
server_id=111
user=mysql
character-set-server=utf8mb4
collation-server=utf8mb4_general_ci
default-authentication-plugin=mysql_native_password
max_connections=800
max_connect_errors=1000

log_bin=mysql_binlog_master2
slow_query_log=ON
slow_query_log_file=/var/lib/mysql/slow.log

log_error=/var/lib/mysql/mysql.err
log_replica_updates=ON
enforce_gtid_consistency=ON
gtid_mode=ON

plugin-load="rpl_semi_sync_source=semisync_source.so;rpl_semi_sync_replica=semisync_replica.so"
#rpl_semi_sync_source_enabled=ON
#rpl_semi_sync_replica_enabled=ON

binlog-ignore-db=information_schema
binlog-ignore-db=mysql
binlog-ignore-db=sys
binlog-ignore-db=performance_schema

[client]
default-character-set=utf8mb4
EOF

執行Master

會自動下載最新版mysql

docker run -d --name mysql_master2 -p 3306:3306 -e MYSQL_ROOT_PASSWORD=admin123456 -e TZ="Asia/Shanghai" -v /home/mysql_config/master2/config:/etc/mysql/conf.d mysql --authentication_policy=mysql_native_password

啟用半同步外掛

此步主要是為了將#rpl_semi_sync_source_enabled=ON和#rpl_semi_sync_replica_enabled=ON的井號去掉

mysql會檢測semisync_source.so和semisync_replica.so外掛的情況，如果沒有安裝就不能設定rpl_semi_sync_source_enabled和rpl_semi_sync_replica_enabled

cat > /home/mysql_config/master2/config/my.cnf <<EOF
[mysqld]
server_id=111
user=mysql
character-set-server=utf8mb4
collation-server=utf8mb4_general_ci
default-authentication-plugin=mysql_native_password
max_connections=800
max_connect_errors=1000

log_bin=mysql_binlog_master2
slow_query_log=ON
slow_query_log_file=/var/lib/mysql/slow.log

log_error=/var/lib/mysql/mysql.err
log_replica_updates=ON
enforce_gtid_consistency=ON
gtid_mode=ON

plugin-load="rpl_semi_sync_source=semisync_source.so;rpl_semi_sync_replica=semisync_replica.so"
rpl_semi_sync_source_enabled=ON
rpl_semi_sync_replica_enabled=ON

binlog-ignore-db=information_schema
binlog-ignore-db=mysql
binlog-ignore-db=sys
binlog-ignore-db=performance_schema

[client]
default-character-set=utf8mb4
EOF

重新開啟

docker restart mysql_master2
docker exec -it mysql_master2 mysql -uroot -padmin123456 -e "show variables like 'rpl_semi_sync_%';"
+---------------------------------------------+------------+
| Variable_name                               | Value      |
+---------------------------------------------+------------+
| rpl_semi_sync_replica_enabled               | ON         |
| rpl_semi_sync_replica_trace_level           | 32         |
| rpl_semi_sync_source_enabled                | ON         |
| rpl_semi_sync_source_timeout                | 10000      |
| rpl_semi_sync_source_trace_level            | 32         |
| rpl_semi_sync_source_wait_for_replica_count | 1          |
| rpl_semi_sync_source_wait_no_replica        | ON         |
| rpl_semi_sync_source_wait_point             | AFTER_SYNC |
+---------------------------------------------+------------+

部署Slave

準備Slave組態檔my.cnf

mkdir /home/mysql_config/slave2
mkdir /home/mysql_config/slave2/config
touch /home/mysql_config/slave2/config/my.cnf
chmod +x /home/mysql_config/slave2/config/my.cnf

cat > /home/mysql_config/slave2/config/my.cnf <<EOF
[mysqld]
server_id=121
user=mysql
character-set-server=utf8mb4
collation-server=utf8mb4_general_ci
default-authentication-plugin=mysql_native_password
max_connections=800
max_connect_errors=1000

log_bin=mysql_binlog_master2_slave2
slow_query_log=ON
slow_query_log_file=/var/lib/mysql/slow.log

log_error=/var/lib/mysql/mysql.err
log_replica_updates=ON     
enforce_gtid_consistency=ON
gtid_mode=ON

binlog-ignore-db=information_schema
binlog-ignore-db=mysql
binlog-ignore-db=sys
binlog-ignore-db=performance_schema

[client]
default-character-set=utf8mb4
EOF

執行Slave

會自動下載最新版mysql

docker run -d --name mysql_master2_slave2 -p 4306:3306 -e MYSQL_ROOT_PASSWORD=admin123456 -e TZ="Asia/Shanghai" -v /home/mysql_config/slave2/config:/etc/mysql/conf.d mysql --authentication_policy=mysql_native_password

主從設定

安裝MySQL使用者端

兩臺Master都需要安裝，而且後續keepalived也需要安裝

在網站查詢https://dev.mysql.com/downloads/repo/yum/要安裝的mysql版本，以mysql80-community-release-el8-4.noarch.rpm舉例

yum module disable mysql
wget https://dev.mysql.com/get/mysql80-community-release-el8-4.noarch.rpm
rpm -ivh mysql80-community-release-el8-4.noarch.rpm
yum install mysql-community-client
yum module enable mysql

編寫指令碼檔案

touch /home/mysql_config/mysql_script.sh
chmod +x /home/mysql_config/mysql_script.sh

cat > /home/mysql_config/mysql_script.sh <<'EOF'
#!/bin/bash
MASTER_RPL_USER=rpl_admin
MASTER_RPL_PASSWORD=rpl_admin123456
# master and slaves admin user
ADMIN_USER=root
ADMIN_PASSWORD=admin123456
ALLOW_HOST=%

MASTER_HOST=192.168.10.130
MASTER_PORT=3306
SLAVE_HOST=192.168.10.130
SLAVE_PORT=4306

# master
DROP_USER_SQL="DROP USER '$MASTER_RPL_USER'@'$ALLOW_HOST';"
CREATE_USER_SQL="CREATE USER '$MASTER_RPL_USER'@'$ALLOW_HOST' IDENTIFIED BY '$MASTER_RPL_PASSWORD';"
GRANT_PRIVILEGES_SQL="GRANT REPLICATION SLAVE ON *.* TO '$MASTER_RPL_USER'@'$ALLOW_HOST';"
FLUSH_PRIVILEGES_SQL="FLUSH PRIVILEGES;"

mysql -h$MASTER_HOST -P$MASTER_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e "$CREATE_USER_SQL"
mysql -h$MASTER_HOST -P$MASTER_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e "$GRANT_PRIVILEGES_SQL"
mysql -h$MASTER_HOST -P$MASTER_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e "$FLUSH_PRIVILEGES_SQL"

# master's slave shell
RESULT=`mysql -h$MASTER_HOST -p$MASTER_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e "SHOW MASTER STATUS;" | grep -v grep |tail -n +2| awk '{print $1,$2}'`
LOG_FILE_NAME=`echo $RESULT | grep -v grep | awk '{print $1}'`
LOG_FILE_POS=`echo $RESULT | grep -v grep | awk '{print $2}'`

SYNC_SQL="change master to master_host='$MASTER_HOST', master_port=$MASTER_PORT, master_user='$MASTER_RPL_USER',master_password='$MASTER_RPL_PASSWORD',master_log_file='$LOG_FILE_NAME',master_log_pos=$LOG_FILE_POS;"
START_SYNC_SQL="start REPLICA;"
STATUS_SQL="show REPLICA status\G;"

mysql -h$SLAVE_HOST -P$SLAVE_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$SYNC_SQL"
mysql -h$SLAVE_HOST -P$SLAVE_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$START_SYNC_SQL"
mysql -h$SLAVE_HOST -P$SLAVE_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$STATUS_SQL"
EOF

執行指令碼並檢查

sh /home/mysql_config/mysql_script.sh
*************************** 1. row ***************************
...
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
...

雙主設定

Master1作為主，Master2作為備份

Master1的IP地址為：192.168.10.129
Master2的IP地址為：192.168.10.130

安裝MySQL使用者端

兩臺Master都需要安裝，而且後續keepalived也需要安裝

在網站查詢https://dev.mysql.com/downloads/repo/yum/要安裝的mysql版本，以mysql80-community-release-el8-4.noarch.rpm舉例

yum module disable mysql
wget https://dev.mysql.com/get/mysql80-community-release-el8-4.noarch.rpm
rpm -ivh mysql80-community-release-el8-4.noarch.rpm
yum install mysql-community-client
yum module enable mysql

編寫組態檔

touch /home/mysql_config/rplShell.sh
chmod +x /home/mysql_config/rplShell.sh

cat > /home/mysql_config/rplShell.sh <<'EOF'
#!/bin/bash
MASTER_RPL_USER=rpl_admin
MASTER_RPL_PASSWORD=rpl_admin123456
# master and slaves admin user
ADMIN_USER=root
ADMIN_PASSWORD=admin123456

MASTER_HOST=192.168.10.130
MASTER_PORT=3306
BACKUP_HOST=192.168.10.129
BACKUP_PORT=3306

RESULT=`mysql -h$MASTER_HOST -P$MASTER_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e "SHOW MASTER STATUS;" | grep -v grep |tail -n +2| awk '{print $1,$2}'`
LOG_FILE_NAME=`echo $RESULT | grep -v grep | awk '{print $1}'`
LOG_FILE_POS=`echo $RESULT | grep -v grep | awk '{print $2}'`

SYNC_SQL="change master to master_host='$MASTER_HOST', master_port=$MASTER_PORT, master_user='$MASTER_RPL_USER',master_password='$MASTER_RPL_PASSWORD',master_log_file='$LOG_FILE_NAME',master_log_pos=$LOG_FILE_POS;"
START_SYNC_SQL="start REPLICA;"
STATUS_SQL="show REPLICA status\G;"

mysql -h$BACKUP_HOST -P$BACKUP_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$SYNC_SQL"
mysql -h$BACKUP_HOST -P$BACKUP_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$START_SYNC_SQL"
mysql -h$BACKUP_HOST -P$BACKUP_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$STATUS_SQL"
EOF

執行指令碼並檢查

sh /home/mysql_config/rplShell.sh
*************************** 1. row ***************************
...
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
...

Master2作為主，Master1作為備份

Master1的IP地址為：192.168.10.129
Master2的IP地址為：192.168.10.130

安裝MySQL使用者端

兩臺Master都需要安裝，而且後續keepalived也需要安裝

在網站查詢https://dev.mysql.com/downloads/repo/yum/要安裝的mysql版本，以mysql80-community-release-el8-4.noarch.rpm舉例

yum module disable mysql
wget https://dev.mysql.com/get/mysql80-community-release-el8-4.noarch.rpm
rpm -ivh mysql80-community-release-el8-4.noarch.rpm
yum install mysql-community-client
yum module enable mysql

編寫組態檔

touch /home/mysql_config/rplShell.sh
chmod +x /home/mysql_config/rplShell.sh

cat > /home/mysql_config/rplShell.sh <<'EOF'
#!/bin/bash
MASTER_RPL_USER=rpl_admin
MASTER_RPL_PASSWORD=rpl_admin123456
# master and slaves admin user
ADMIN_USER=root
ADMIN_PASSWORD=admin123456

MASTER_HOST=192.168.10.129
MASTER_PORT=3306
BACKUP_HOST=192.168.10.130
BACKUP_PORT=3306

RESULT=`mysql -h$MASTER_HOST -P$MASTER_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e "SHOW MASTER STATUS;" | grep -v grep |tail -n +2| awk '{print $1,$2}'`
LOG_FILE_NAME=`echo $RESULT | grep -v grep | awk '{print $1}'`
LOG_FILE_POS=`echo $RESULT | grep -v grep | awk '{print $2}'`

SYNC_SQL="change master to master_host='$MASTER_HOST', master_port=$MASTER_PORT, master_user='$MASTER_RPL_USER',master_password='$MASTER_RPL_PASSWORD',master_log_file='$LOG_FILE_NAME',master_log_pos=$LOG_FILE_POS;"
START_SYNC_SQL="start REPLICA;"
STATUS_SQL="show REPLICA status\G;"

mysql -h$BACKUP_HOST -P$BACKUP_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$SYNC_SQL"
mysql -h$BACKUP_HOST -P$BACKUP_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$START_SYNC_SQL"
mysql -h$BACKUP_HOST -P$BACKUP_PORT -u"$ADMIN_USER" -p"$ADMIN_PASSWORD" -e"$STATUS_SQL"
EOF

執行指令碼並檢查

sh /home/mysql_config/rplShell.sh
*************************** 1. row ***************************
...
             Slave_IO_Running: Yes
            Slave_SQL_Running: Yes
...

設定Keepalived

Master1主機設定

安裝keepalived

yum install -y keepalived

編寫keepalived組態檔

cat > /etc/keepalived/keepalived.conf <<'EOF'
! Configuration File for keepalived

global_defs {
    router_id HA-M1
    script_user root
}

vrrp_script chk_mysql {
    script /etc/keepalived/chk_mysql.sh
    interval 3
    fall 3
    rise 2
}

vrrp_instance VI_MYSQL {
    state MASTER
    interface ens160
    virtual_router_id 100
    priority 100
    advert_int 1
    unicast_src_ip  192.168.10.129
    unicast_peer {
            192.168.10.130
    }
    
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    
    virtual_ipaddress {
        192.168.10.100/24 dev ens160 label ens160:vip
    }
    
    track_script {
        chk_mysql
    }
}
EOF

router_id：標識，兩臺需不一樣
state MASTER：表明這臺是Master角色
priority：優先順序，MASTER角色比BACKUP高
virtual_router_id：虛擬路由編號，兩臺需要一致，兩個節點不能一樣
192.168.10.100 dev ens32 label ens32:vip：VIP地址—192.168.10.100
script /etc/keepalived/chk_mysql.sh：MySQL的檢測指令碼，定時去檢測MySQL程序是否掛掉，會重啟，interval是為間隔時間（2s檢測一次）

當Keepalived從BACKUP提升為MASTER時，那麼VIP就會漂移到自己身上，這個時候我們只需要將Slave掛載在自己身上即可

MySQL狀態監測指令碼

安裝MySQL使用者端

在網站查詢https://dev.mysql.com/downloads/repo/yum/要安裝的mysql版本，以mysql80-community-release-el8-4.noarch.rpm舉例

wget https://dev.mysql.com/get/mysql80-community-release-el8-4.noarch.rpm
rpm -ivh mysql80-community-release-el8-4.noarch.rpm
yum module disable mysql
yum install mysql-community-client
yum module enable mysql

設定Keepalived的MySQL狀態監測指令碼

touch /etc/keepalived/chk_mysql.sh
chmod +x /etc/keepalived/chk_mysql.sh

cat > /etc/keepalived/chk_mysql.sh <<'EOF'
#!/bin/bash
MYSQL=/usr/bin/mysql
MYSQL_HOST=192.168.10.129
MYSQL_USER=root
MYSQL_PASSWORD=admin123456
CHECK_TIME=3
  
#mysql  is working MYSQL_OK is 1 , mysql down MYSQL_OK is 0
  
MYSQL_OK=1
  
function check_mysql_helth (){
    $MYSQL -h $MYSQL_HOST -u$MYSQL_USER -p${MYSQL_PASSWORD} -e "show status;" >/dev/null 2>&1
    if [ $? = 0 ] ;then
    MYSQL_OK=1
    else
    MYSQL_OK=0
    fi
    return $MYSQL_OK
}
while [ $CHECK_TIME -ne 0 ]
do
    let "CHECK_TIME -= 1"
    check_mysql_helth
if [ $MYSQL_OK = 1 ] ; then
    CHECK_TIME=0
    exit 0
fi
if [ $MYSQL_OK -eq 0 ] &&  [ $CHECK_TIME -eq 0 ]
then
    systemctl stop keepalived
    exit 1
fi
sleep 1
done
EOF

Master2備機設定

安裝keepalived

yum install -y keepalived

編寫keepalived組態檔

cat > /etc/keepalived/keepalived.conf <<'EOF'
! Configuration File for keepalived

global_defs {
    router_id HA-M2
    script_user root
}

vrrp_script chk_mysql {
    script /etc/keepalived/chk_mysql.sh
    interval 3
    fall 3
    rise 2
}

vrrp_instance VI_MYSQL {
    state BACKUP
    interface ens160
    virtual_router_id 100
    nopreempt
    priority 50
    advert_int 1
    unicast_src_ip  192.168.10.130
    unicast_peer {
            192.168.10.129
    }
    
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    
    virtual_ipaddress {
        192.168.10.100/24 dev ens160 label ens160:vip
    }
    
    track_script {
        chk_mysql
    }
}
EOF

注意router_id需要不一樣，state BACKUP表明是備機，virtual_router_id需要一致，priority要比MASTER低！

chk_mysql.sh內容如下，可以看到可以根據當前Keepalived的狀態分別處理，但是此處的處理都是啟動MySQL（如果MySQL程序已退出）

MySQL狀態監測指令碼

安裝MySQL使用者端

在網站查詢https://dev.mysql.com/downloads/repo/yum/要安裝的mysql版本，以mysql80-community-release-el8-4.noarch.rpm舉例

wget https://dev.mysql.com/get/mysql80-community-release-el8-4.noarch.rpm
rpm -ivh mysql80-community-release-el8-4.noarch.rpm
yum module disable mysql
yum install mysql-community-client
yum module enable mysql

設定Keepalived的MySQL狀態監測指令碼

touch /etc/keepalived/chk_mysql.sh
chmod +x /etc/keepalived/chk_mysql.sh

cat > /etc/keepalived/chk_mysql.sh <<'EOF'
#!/bin/bash
MYSQL=/usr/bin/mysql
MYSQL_HOST=192.168.10.130
MYSQL_USER=root
MYSQL_PASSWORD=admin123456
CHECK_TIME=3
  
#mysql  is working MYSQL_OK is 1 , mysql down MYSQL_OK is 0

MYSQL_OK=1
  
function check_mysql_helth (){
    $MYSQL -h $MYSQL_HOST -u$MYSQL_USER -p${MYSQL_PASSWORD} -e "show status;" >/dev/null 2>&1
    if [ $? = 0 ] ;then
    MYSQL_OK=1
    else
    MYSQL_OK=0
    fi
    return $MYSQL_OK
}
while [ $CHECK_TIME -ne 0 ]
do
    let "CHECK_TIME -= 1"
    check_mysql_helth
if [ $MYSQL_OK = 1 ] ; then
    CHECK_TIME=0
    exit 0
fi
if [ $MYSQL_OK -eq 0 ] &&  [ $CHECK_TIME -eq 0 ]
then
    systemctl stop keepalived
    exit 1
fi
sleep 1
done
EOF

啟動Keepalived

最後在Master1和Master2分別啟動Keepalived

systemctl start keepalived

檢視Master1網路設定

ifconfig
ens160: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.10.129  netmask 255.255.255.0  broadcast 192.168.10.255
        inet6 fe80::20c:29ff:fe23:aab2  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:23:aa:b2  txqueuelen 1000  (Ethernet)
        RX packets 4797  bytes 524410 (512.1 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2860  bytes 332307 (324.5 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

ens160:vip: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.10.100  netmask 255.255.255.255  broadcast 0.0.0.0
        ether 00:0c:29:23:aa:b2  txqueuelen 1000  (Ethernet)

檢視Master2網路設定

ens160: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.10.130  netmask 255.255.255.0  broadcast 192.168.10.255
        inet6 fe80::20c:29ff:feb4:3ede  prefixlen 64  scopeid 0x20<link>
        ether 00:0c:29:b4:3e:de  txqueuelen 1000  (Ethernet)
        RX packets 4672  bytes 2048171 (1.9 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 2703  bytes 275576 (269.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

主機上有ens160:vip而備機上沒有vip

Keepalived可能會遇到的問題

主機能啟動，備機不能啟動
1. 關閉防火牆
2. 兩臺機器的網路卡uuid是否衝突（如果是vm ware複製的linux，因為網路卡uuid一致導致的）
主機和備機keepalived都為master，有兩種方法
- 關閉防火牆，或設定組播ip可用
- 兩端keepalived設定為單播（使用unicast_src_ip ）

測試

資料同步測試

進入Master1，建立資料庫test_db，表test_user ，並插入一條資料。

docker exec -it mysql_master1 mysql -uroot -padmin123456 -e "CREATE DATABASE test_db;"
docker exec -it mysql_master1 mysql -uroot -padmin123456 -e "CREATE TABLE test_db.test_user (id INT(11),name VARCHAR(25),age int(11) );"
docker exec -it mysql_master1 mysql -uroot -padmin123456 -e "INSERT INTO test_db.test_user values (1,'zhangsan',18);"
docker exec -it mysql_master1 mysql -uroot -padmin123456 -e "SELECT * FROM test_db.test_user;"

檢視Master1及從庫master1_slave1、檢視Master2及從庫master2_slave2的資料同步情況

docker exec -it mysql_master1 mysql -uroot -padmin123456 -e "SELECT * FROM test_db.test_user;"
+------+----------+------+
| id   | name     | age  |
+------+----------+------+
|    1 | zhangsan |   18 |
+------+----------+------+

docker exec -it mysql_master1_slave1 mysql -uroot -padmin123456 -e "SELECT * FROM test_db.test_user;"
+------+----------+------+
| id   | name     | age  |
+------+----------+------+
|    1 | zhangsan |   18 |
+------+----------+------+

docker exec -it mysql_master2 mysql -uroot -padmin123456 -e "SELECT * FROM test_db.test_user;"
+------+----------+------+
| id   | name     | age  |
+------+----------+------+
|    1 | zhangsan |   18 |
+------+----------+------+

docker exec -it mysql_master2_slave2 mysql -uroot -padmin123456 -e "SELECT * FROM test_db.test_user;"
+------+----------+------+
| id   | name     | age  |
+------+----------+------+
|    1 | zhangsan |   18 |
+------+----------+------+

高可用測試

啟用備機測試

停止主機上的mysql

docker stop mysql_master1

主機上的Keepalived狀態

Keepalived[4213]: Stopping
Keepalived_vrrp[4214]: (VI_MYSQL) sent 0 priority
Keepalived_vrrp[4214]: (VI_MYSQL) removing VIPs.

備機的Keepalived狀態

Keepalived_vrrp[8986]: (VI_MYSQL) Backup received priority 0 advertisement
Keepalived_vrrp[8986]: (VI_MYSQL) Receive advertisement timeout
Keepalived_vrrp[8986]: (VI_MYSQL) Entering MASTER STATE
Keepalived_vrrp[8986]: (VI_MYSQL) setting VIPs.
Keepalived_vrrp[8986]: (VI_MYSQL) Sending/queueing gratuitous ARPs on ens160 for 192.168.10.100

注意
Master備機上做寫操作，第一次寫會發生半同步等待（10s左右），第二次寫會退化成非同步複製

主機恢復測試

啟動主機上的mysql和keepalived

docker start mysql_master1
systemctl start keepalived

主機上的Keepalived狀態

Keepalived_vrrp[5413]: (VI_MYSQL) Entering BACKUP STATE
Keepalived_vrrp[5413]: VI_MYSQL: sending gratuitous ARP for 192.168.10.129
Keepalived_vrrp[5413]: Sending gratuitous ARP on ens160 for 192.168.10.129
Keepalived_vrrp[5413]: (VI_MYSQL) received lower priority (50) advert from 192.168.10.130 - discarding
Keepalived_vrrp[5413]: (VI_MYSQL) received lower priority (50) advert from 192.168.10.130 - discarding
Keepalived_vrrp[5413]: (VI_MYSQL) received lower priority (50) advert from 192.168.10.130 - discarding
Keepalived_vrrp[5413]: (VI_MYSQL) Receive advertisement timeout
Keepalived_vrrp[5413]: (VI_MYSQL) Entering MASTER STATE
Keepalived_vrrp[5413]: (VI_MYSQL) setting VIPs.
Keepalived_vrrp[5413]: (VI_MYSQL) Sending/queueing gratuitous ARPs on ens160 for 192.168.10.100
Keepalived_vrrp[5413]: Sending gratuitous ARP on ens160 for 192.168.10.100
Keepalived_vrrp[5413]: Sending gratuitous ARP on ens160 for 192.168.10.100
Keepalived_vrrp[5413]: Sending gratuitous ARP on ens160 for 192.168.10.100
Keepalived_vrrp[5413]: Sending gratuitous ARP on ens160 for 192.168.10.100
Keepalived_vrrp[5413]: Sending gratuitous ARP on ens160 for 192.168.10.100

備機的Keepalived狀態

Keepalived_vrrp[8986]: (VI_MYSQL) Master received advert from 192.168.10.129 with higher priority 100, ours 50
Keepalived_vrrp[8986]: (VI_MYSQL) Entering BACKUP STATE
Keepalived_vrrp[8986]: (VI_MYSQL) removing VIPs.

結論

如果殺掉主機上的mysql

VIP會漂移到備機上，ifconfig能看到VIP資訊
備機的Keepalived從BACKUP狀態轉換為了MASTER狀態
Master備機上做寫操作，第一次寫會發生半同步等待（10s左右），第二次寫會退化成非同步複製

恢復主機mysql

ifconfig看下VIP會漂移回來，並且備機上的VIP會消失
剛才在Master備機上寫入的資料同步過來了
Keepalived的狀態是從FAULT轉變為BACKUP，最後變成MASTER

一鍵部署MySQL8+keepalived雙主熱備高可用

概述

部署流程

設定第一臺Master

部署Master

準備Master組態檔my.cnf

執行Master

啟動半同步外掛

重新開啟

部署Slave

準備Slave組態檔my.cnf

執行Slave

主從設定

安裝MySQL使用者端

編寫指令碼檔案

執行指令碼並檢查

設定第二臺

部署Master

準備Master組態檔my.cnf

執行Master

啟用半同步外掛

重新開啟

部署Slave

準備Slave組態檔my.cnf

執行Slave

主從設定

安裝MySQL使用者端

編寫指令碼檔案

執行指令碼並檢查

雙主設定

Master1作為主，Master2作為備份

安裝MySQL使用者端

編寫組態檔

執行指令碼並檢查

Master2作為主，Master1作為備份

安裝MySQL使用者端

編寫組態檔

執行指令碼並檢查

設定Keepalived

Master1主機設定

安裝keepalived

編寫keepalived組態檔

MySQL狀態監測指令碼

安裝MySQL使用者端

設定Keepalived的MySQL狀態監測指令碼

Master2備機設定

安裝keepalived

編寫keepalived組態檔

MySQL狀態監測指令碼

安裝MySQL使用者端

設定Keepalived的MySQL狀態監測指令碼

啟動Keepalived

Keepalived可能會遇到的問題

測試

資料同步測試

高可用測試

啟用備機測試

主機恢復測試

結論