centOS7.7系統yum安裝mysql5.7主從複製+keepalive高可用HA

1.準備環境

1.1.準備兩臺機器

ip	說明
192.168.124.101	master 主庫機器
192.168.124.102	slave 從庫機器

1.2.在兩臺機器安裝mysql5.7

1.2.1卸載已有數據庫

在CentOS中默認安裝有MariaDB，這個是MySQL的分支，但爲了需要，還是要在系統中安裝MySQL，而且安裝完成之後可以直接覆蓋掉MariaDB。

#查詢已安裝的數據庫
rpm -qa|grep mariadb

#選擇卸載 --nodeps
rpm -e --nodeps mariadb-libs-5.5.65-1.el7.x86_64

1.2.2下載mysql官方Yum倉庫

下載並安裝MySQL官方的 Yum Repository

wget -i -c http://dev.mysql.com/get/mysql57-community-release-el7-10.noarch.rpm

1.2.3 安裝yum倉庫

下載完成Yum倉庫後，就可以直接yum安裝了

yum -y install mysql57-community-release-el7-10.noarch.rpm

1.2.4 安裝mysql

通過剛剛安裝的yum倉庫，直接使用yum來安裝mysql服務

yum -y install mysql-community-server

1.3 配置mysql

首先啓動Mysql。然後查看MySQL運行狀態，運行狀態如圖

systemctl start  mysqld.service
systemctl status mysqld.service

此時MySQL已經開始正常運行，不過要想進入MySQL還得先找出此時root用戶的密碼，通過如下命令可以在日誌文件中找出密碼：

grep "password" /var/log/mysqld.log

如下命令進入數據庫

輸入初始密碼，此時不能做任何事情，因爲MySQL默認必須修改密碼之後才能操作數據庫：

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
ERROR 1819 (HY000): Your password does not satisfy the current policy requirements

這裏有個問題，新密碼設置的時候如果設置的過於簡單會報錯：

MySQL完整的初始密碼規則可以通過如下命令查看：

mysql> set global validate_password_policy=0;
mysql> set global validate_password_length=1;

設置之後就是我上面查出來的那幾個值了，此時密碼就可以設置的很簡單，例如123456之類的。到此數據庫的密碼設置就完成了。

但此時還有一個問題，就是因爲安裝了Yum Repository，以後每次yum操作都會自動更新，需要把這個卸載掉

yum -y remove mysql57-community-release-el7-10.noarch

最後一步：

#進入mysql
#mysql -uroot -p123456
mysql> use mysql
update user set host='%' where user='root';
flush privileges;

ok,用你的navicat就可以遠程連接了

2.配置主從複製

主庫可寫(會寫入從庫)可讀，從庫只能讀

2.1主機主從設定

對剛剛安裝mysql完成的兩臺主機，設定主從劃分：

192.168.124.101  master 主庫機器
192.168.124.102  slave 從庫機器

2.2 配置

2.2.1 配置 master 主庫機器

2.2.1.1開啓binlog

設置mysql的唯一編號(mysql5.7即更高版本新加參數)， 和開啓binlog日誌
輸入vim /etc/my.cnf 進入配置文件，按Insert鍵進入編輯模式，添加如下參數

server-id=101 #機器的唯一標識,一般設定爲IP最後一段
log-bin=/var/lib/mysql/mysql-bin #開啓binlog

重新啓動

systemctl restart mysqld.service
#或
service mysqld restart

進入mysql,查看binlog是否開啓成功
輸入：

cd /var/lib/mysql

看到如下文件代表開啓成功

開啓成功。

2.2.1.2 創建用戶並授權

登錄MySQL

mysql -uroot -p

授權:

grant replication slave on *.* to 'root'@'%' identified by '123456';

2.2.2 配置slave 從庫機器

2.2.2.1開啓binlog

輸入vi /etc/my.cnf 進入配置文件，按Insert鍵進入編輯模式，添加如下參數

#server-id機器的唯一標識
server-id=102
#打開slave的relaylog功能
relay-log-index=slave-relay-bin.index
relay-log=slave-relay-bin

重新啓動

systemctl restart mysqld.service
#或
service mysqld restart

2.3 建立主從關係

2.3.1 打開主庫機器master登錄mysql

輸入查看狀態

[root@localhost mysql]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1222
Server version: 5.7.30-log MySQL Community Server (GPL)

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |    89334 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

mysql>

2.3.2 打開從庫機器slave登錄mysql

[root@localhost network-scripts]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 1316
Server version: 5.7.30 MySQL Community Server (GPL)

Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show slave status\G;

輸入 show slave status\G; 查看狀態，狀態未開啓時進行如下設置：

change master to master_host='master_ip'; # 主節點
change master to master_port=3306; #主節點的端口號
change master to master_user='root'; # 賬號
change master to master_password='123456'; # 密碼
#show master status 對應的的日誌File
change master to master_log_file='mysql-bin.000001';
#show master status 對應的Position
change master to master_log_pos=89334;

輸入start slave 開啓從節點

#開啓從節點
start slave
#再次查看從機狀態，已成功開啓
show slave status\G;

到此，主從複製配置完成了

3.HA高可用配置

Mysql+keepalive高可用自動切換

3.1下載安裝keepalive

192.168.124.101 master 主庫機器
192.168.124.102 slave 從庫機器
一下操作主機master、備機slave都需要操作
1.安裝環境依賴(主機備機都要安裝)

yum install -y openssl-devel popt-devel  curl gcc  libnl3-devel net-snmp-devel  libnfnetlink-devel

2.下載安裝包(主機備機都要安裝)

wget https://www.keepalived.org/software/keepalived-2.0.0.tar.gz 

解壓縮、編譯、安裝

tar -zxf keepalived-2.0.0.tar.gz 
cd keepalived-2.0.0
./configure --prefix=/usr/local/keepalived
make && make install
echo $?
0

cp /usr/local/keepalived/sbin/keepalived /usr/sbin/
cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/
cp ./keepalived/etc/init.d/keepalived /etc/init.d/
mkdir /etc/keepalived
cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/

3.2 配置

master主機192.168.124.101

cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
   notification_email {
     [email protected]
     [email protected]
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
   vrrp_skip_check_adv_addr
   #vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_instance VI_1 {
    state MASTER
    interface enp2s0 #ifconfig查看配置成你自己主機的網卡
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.124.16
    }
}

 virtual_server 192.168.124.16 3306 {           #LVS配置，VIP
    delay_loop 6                                #服務輪詢的時間間隔
    lb_algo wrr                                 #LVS 調度算法
    lb_kind DR　　　　　　　　　　　　　　　　　#LVS 集羣算法
    persistence_timeout 60                      #同一IP的鏈接50秒內被分配到同一臺realserver
    protocol TCP                                #用TCP協議檢查realserver狀態
    real_server 192.168.124.101 3306 {        #實際服務器的IP和端口
        weight 100
        notify_down /data/sh/mysql.sh
        TCP_CHECK {
        connect_timeout 10
        nb_get_retry 3
        delay_before_retry 3
        connect_port 3306
        }
    }
}

slave從機192.168.124.102

! Configuration File for keepalived

global_defs {
   notification_email {
     [email protected]
     [email protected]
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL
   vrrp_skip_check_adv_addr
   #vrrp_strict
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_instance VI_1 {
    state MASTER
    interface enp2s0 #ifconfig查看配置成你自己主機的網卡
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.124.16 
    }
}

 virtual_server 192.168.124.16 3306 {           #LVS配置，VIP
    delay_loop 6                                #服務輪詢的時間間隔
    lb_algo wrr                                 #LVS 調度算法
    lb_kind DR　　　　　　　　　　　　　　　　　#LVS 集羣算法
    persistence_timeout 60                      #同一IP的鏈接50秒內被分配到同一臺realserver
    protocol TCP                                #用TCP協議檢查realserver狀態
    real_server 192.168.124.102 3306 {        #實際服務器的IP和端口
        weight 90
        notify_down /data/sh/mysql.sh
        TCP_CHECK {
        connect_timeout 10
        nb_get_retry 3
        delay_before_retry 3
        connect_port 3306
        }
    }
}

在master/slave兩端/data/sh/mysql.sh建立關閉keepalived的腳本

mkdir -p /data/sh/
touch mysql.sh

腳本內容：

#!/bin/bash
pkill keepalived

3.3 啓動

master和backup都啓動keepalived服務

service keepalived start
netstat -lantup | grep keep
/etc/init.d/keepalived restart

查看兩端的虛擬IP啓動情況，系統日誌
master

ip addr

backup

ip addr

到此，你就可以使用VIP(虛擬IP)來操作啦！

ping 192.168.126.16

4.問題解決

4.1.MYSQL同步故障：" SLAVE_SQL_RUNNING:NO" 兩種解決辦法

進入slave服務器，運行：

mysql> show slave status\G

Relay_Log_File: localhost-relay-bin.000535
Relay_Log_Pos: 21795072
Relay_Master_Log_File: localhost-bin.000094
Slave_IO_Running: Yes
Slave_SQL_Running: No
Replicate_Do_DB:
Replicate_Ignore_DB:

解決辦法一、

Slave_SQL_Running: No
1.程序可能在slave上進行了寫操作

2.也可能是slave機器重起後，事務回滾造成的.

一般是事務回滾造成的：
解決辦法：

mysql> stop slave ;
mysql> set GLOBAL SQL_SLAVE_SKIP_COUNTER=1;
mysql> start slave ;

解決辦法二、

首先停掉Slave服務：stop slave;
到主服務器上查看主機狀態：
記錄File和Position對應的值

進入master

mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000002 |   173749 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

在slave節點重新配置一下

stop slave;
change master to master_host='master_ip'; # 主節點
change master to master_port=3306; #主節點的端口號
change master to master_user='root'; # 賬號
change master to master_password='123456'; # 密碼
#show master status 對應的的日誌File
change master to master_log_file='mysql-bin.000001';
#show master status 對應的Position
change master to master_log_pos=89334;

輸入start slave 開啓從節點

mysql> start slave;
mysql> show slave status\G;

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參考文檔：
https://www.cnblogs.com/biehongli/p/11160839.html
https://blog.csdn.net/qq_16676539/article/details/81906959
https://www.cnblogs.com/zwj-linux/p/11552364.html