Keepalived+LVS+MySQL双主复制实现读写负载均衡及高可用实战教程

2020-09-03 03:19:47 字数 6687 阅读 548

# 一、简介
#### 1. Keepalived
* [Keepalived](http://www.keepalived.org/) 是一个基于 [VRRP](http://datatracker.ietf.org/wg/vrrp/documents/) （虚拟路由冗余协议）可用来实现服务高可用性的软件方案，避免出现单点故障。Keepalived一般用来实现轻量级高可用性，且不需要共享存储，一般用于两个节点之间，常见有LVS+Keepalived、Nginx+Keepalived组合。
 
#### 2. LVS
* [LVS](http://www.linux-vs.org/index.html) (Linux Virtual Server)是一个高可用性虚拟的服务器集群系统。本项目在1998年5月由章文嵩博士成立，是中国国内最早出现的自由软件项目之一。
LVS主要用于多服务器的负载均衡，作用于网络层。LVS构建的服务器集群系统中，前端的负载均衡层被称为Director Server；后端提供服务的服务器组层被称为Real Server。通过下图可以大致了解LVS的基础架构。
* 本文中将利用LVS实现MySQL的读写负载均衡，Keepalived避免节点出现单点故障。
 
#### 3. MySQL双主复制
* 参考[MySQL主主复制详细教程
](https://www.jianshu.com/p/591662b9a461)
 
# 二、安装配置
* 192.168.245.66：Keepalived + LVS Master 
192.168.245.88：Keepalived + LVS Slave
192.168.245.22：MySQL Replication Master 
192.168.245.33：MySQL Replication Master
192.168.245.100：VIP（虚拟IP）
192.168.245.11：Web服务器（测试用）
 
# 三、服务器192.168.245.66配置Keepalived + LVS Master
#### 1. 安装LVS 
```
yum -y install ipvsadm
```
#### 2. 下载安装Keepalived
```
yum install -y gcc
yum install -y kernel-devel openssl openssl-devel
```
```
wget -q http://www.keepalived.org/software/keepalived-1.2.13.tar.gz
tar -zxvf keepalived-1.2.13.tar.gz
cd keepalived-1.2.13
./configure && make && make install
cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/sbin/keepalived /usr/sbin/
chkconfig --add keepalived
chkconfig --level 345 keepalived on
```
#### 3. Keepalived配置文件修改
```
vim /etc/keepalived/keepalived.conf
```
* 修改内容如下
 
```
! Configuration File for keepalived
 
global_defs {
   router_id LVS1
}
 
vrrp_instance VI_1 {
    state MASTER #指定instance初始状态，实际根据优先级决定.backup节点不一样
    interface ens33 #虚拟IP所在网卡通过 ifconfig可以查看
    virtual_router_id 51 #VRID，相同VRID为一个组，决定多播MAC地址
    priority 100 #优先级，另一台改为90.backup节点不一样
    advert_int 1  #检查间隔
    authentication {
        auth_type PASS  #认证方式，可以是pass或ha
        auth_pass 1111  #认证密码
    }
    virtual_ipaddress {
        192.168.245.100  #VIP
    }
}
 
virtual_server 192.168.245.100 3306 {
    delay_loop 6  #服务轮询的时间间隔
    lb_algo wrr  #加权轮询调度，LVS调度算法 rr|wrr|lc|wlc|lblc|sh|sh
    lb_kind DR   #LVS集群模式 NAT|DR|TUN，其中DR模式要求负载均衡器网卡必须有一块与物理网卡在同一个网段
    #nat_mask 255.255.255.0
    persistence_timeout 50  #会话保持时间
    protocol TCP  #健康检查协议
 
     ## Real Server设置，3306就是MySQL连接端口
    real_server 192.168.245.22 3306 {
        weight 3  ##权重
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
    real_server 192.168.245.33 3306 {
        weight 3
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}
```
#### 4. 启动Keepalived
```
systemctl start keeplived
```
#### 5. 查看虚拟网卡添加是否成功
```
ip a
```
* 如图会出现虚拟网卡
 
![](https://upload-images.jianshu.io/upload_images/21643577-b5f94beea8fd719b.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/800)
 
# 四、服务器192.168.245.88配置Keepalived + LVS Slave
#### 1. 安装LVS 
```
yum -y install ipvsadm
```
#### 2. 下载安装Keepalived
```
yum install -y gcc
yum install -y kernel-devel openssl openssl-devel
```
```
wget -q http://www.keepalived.org/software/keepalived-1.2.13.tar.gz
tar -zxvf keepalived-1.2.13.tar.gz
cd keepalived-1.2.13
./configure && make && make install
cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/sbin/keepalived /usr/sbin/
chkconfig --add keepalived
chkconfig --level 345 keepalived on
```
#### 3. Keepalived配置文件修改
```
vim /etc/keepalived/keepalived.conf
```
* 修改内容如下
 
```
! Configuration File for keepalived
 
global_defs {
   router_id LVS1
}
 
vrrp_instance VI_1 {
    state BACKUP #指定instance初始状态，实际根据优先级决定.backup节点不一样
    interface ens33 #虚拟IP所在网卡通过 ifconfig可以查看
    virtual_router_id 51 #VRID，相同VRID为一个组，决定多播MAC地址
    priority 90 #优先级，另一台改为90.backup节点不一样
    advert_int 1  #检查间隔
    authentication {
        auth_type PASS  #认证方式，可以是pass或ha
        auth_pass 1111  #认证密码
    }
    virtual_ipaddress {
        192.168.245.100  #VIP
    }
}
 
virtual_server 192.168.245.100 3306 {
    delay_loop 6  #服务轮询的时间间隔
    lb_algo wrr  #加权轮询调度，LVS调度算法 rr|wrr|lc|wlc|lblc|sh|sh
    lb_kind DR   #LVS集群模式 NAT|DR|TUN，其中DR模式要求负载均衡器网卡必须有一块与物理网卡在同一个网段
    #nat_mask 255.255.255.0
    persistence_timeout 50  #会话保持时间
    protocol TCP  #健康检查协议
 
     ## Real Server设置，3306就是MySQL连接端口
    real_server 192.168.245.22 3306 {
        weight 3  ##权重
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
    real_server 192.168.245.33 3306 {
        weight 3
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}
```
#### 4. 启动Keepalived
```
systemctl start keeplived
```
#### 5. 查看虚拟网卡添加是否成功
```
ip a
```
* 由于Master上已经有虚拟网卡了，Slave上是不显示的，只有当Master出现故障时Slave才会有
 
![](https://upload-images.jianshu.io/upload_images/21643577-3b2ab30b8a20dbb2.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
 
# 五、在数据服务器编写RealServer的网络配置脚本
 
* #### 两个数据服务器192.168.245.22和192.168.245.33进行同样操作。
 
#### 1.添加RealServer脚本
```
vim /etc/init.d/realserver
```
```
#!/bin/sh
VIP=192.168.245.100
. /etc/rc.d/init.d/functions
 
case "$1" in
# 禁用本地的ARP请求、绑定本地回环地址
start)
    /sbin/ifconfig lo down
    /sbin/ifconfig lo up
    echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
    echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
    /sbin/sysctl -p >/dev/null 2>&1
    /sbin/ifconfig lo:0 $VIP netmask 255.255.255.255 up # 在回环地址上绑定VIP，设定掩码，与Direct Server上自身的IP保持通信
    /sbin/route add -host $VIP dev lo:0
    echo "LVS-DR real server starts successfully.\n"
    ;;
stop)
    /sbin/ifconfig lo:0 down
    /sbin/route del $VIP >/dev/null 2>&1
    echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
    echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
echo "LVS-DR real server stopped.\n"
    ;;
status)
    isLoOn=`/sbin/ifconfig lo:0 | grep "$VIP"`
    isRoOn=`/bin/netstat -rn | grep "$VIP"`
    if [ "$isLoON" == "" -a "$isRoOn" == "" ]; then
        echo "LVS-DR real server has run yet."
    else
        echo "LVS-DR real server is running."
    fi
    exit 3
    ;;
*)
    echo "Usage: $0 {start|stop|status}"
    exit 1
esac
exit 0
```
#### 2. 修改脚本权限并启动realserver
```
chmod +x /etc/init.d/realserver
echo "/etc/init.d/realserver" >> /etc/rc.d/rc.local
service realserver start
```
#### 3. 查看虚拟网卡
```
ip a
``` 
* 出现虚拟网卡
 
![](https://upload-images.jianshu.io/upload_images/21643577-bb09b58f5960146c.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)
 
# 六、查看LVS集群状态
```
ipvsadm -Ln
```
```
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.245.100:3306 wrr persistent 50
  -> 192.168.245.22:3306          Route   1      0          0         
  -> 192.168.245.33:3306          Route   1      0          0  
```
# 七、测试
在WEB服务器（192.168.245.11）上，添加测试文件mysql.php
```
<?php
/**
 * Created by PhpStorm.
 * User: wen
 * Date: 7/22/2020
 * Time: 5:00 PM
 */
 
$servername = "192.168.245.100";
$username = "root";
$password = "123123";
$dbname = "test";
 
// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);
// 检测连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}{
    echo "连接成功";
}
 
$sql = "INSERT INTO activity (admin_id, user_id, name)
VALUES ('1', '122', 'keepalived1')";
 
if ($conn->query($sql) === TRUE) {
    echo "新记录插入成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}
 
$conn->close();
?>
```
* 在浏览器访问 [http://192.168.245.11/mysql.php](http://192.168.245.11/mysql.php) 即可进行测试。

# 一、简介
#### 1. Keepalived
* [Keepalived](http://www.keepalived.org/) 是一个基于 [VRRP](http://datatracker.ietf.org/wg/vrrp/documents/) （虚拟路由冗余协议）可用来实现服务高可用性的软件方案，避免出现单点故障。Keepalived一般用来实现轻量级高可用性，且不需要共享存储，一般用于两个节点之间，常见有LVS+Keepalived、Nginx+Keepalived组合。

#### 2. LVS
* [LVS](http://www.linux-vs.org/index.html) (Linux Virtual Server)是一个高可用性虚拟的服务器集群系统。本项目在1998年5月由章文嵩博士成立，是中国国内最早出现的自由软件项目之一。
LVS主要用于多服务器的负载均衡，作用于网络层。LVS构建的服务器集群系统中，前端的负载均衡层被称为Director Server；后端提供服务的服务器组层被称为Real Server。通过下图可以大致了解LVS的基础架构。
* 本文中将利用LVS实现MySQL的读写负载均衡，Keepalived避免节点出现单点故障。

#### 3. MySQL双主复制
* 参考[MySQL主主复制详细教程
](https://www.jianshu.com/p/591662b9a461)

# 二、安装配置
* 192.168.245.66：Keepalived + LVS Master 
192.168.245.88：Keepalived + LVS Slave
192.168.245.22：MySQL Replication Master 
192.168.245.33：MySQL Replication Master
192.168.245.100：VIP（虚拟IP）
192.168.245.11：Web服务器（测试用）

# 三、服务器192.168.245.66配置Keepalived + LVS Master
#### 1. 安装LVS 
```
yum -y install ipvsadm
```
#### 2. 下载安装Keepalived
```
yum install -y gcc
yum install -y kernel-devel openssl openssl-devel
```
```
wget -q http://www.keepalived.org/software/keepalived-1.2.13.tar.gz
tar -zxvf keepalived-1.2.13.tar.gz
cd keepalived-1.2.13
./configure && make && make install
cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/sbin/keepalived /usr/sbin/
chkconfig --add keepalived
chkconfig --level 345 keepalived on
```
#### 3. Keepalived配置文件修改
```
vim /etc/keepalived/keepalived.conf
```
* 修改内容如下

```
! Configuration File for keepalived

global_defs {
   router_id LVS1
}

vrrp_instance VI_1 {
    state MASTER #指定instance初始状态，实际根据优先级决定.backup节点不一样
    interface ens33 #虚拟IP所在网卡通过 ifconfig可以查看
    virtual_router_id 51 #VRID，相同VRID为一个组，决定多播MAC地址
    priority 100 #优先级，另一台改为90.backup节点不一样
    advert_int 1  #检查间隔
    authentication {
        auth_type PASS  #认证方式，可以是pass或ha
        auth_pass 1111  #认证密码
    }
    virtual_ipaddress {
        192.168.245.100  #VIP
    }
}

virtual_server 192.168.245.100 3306 {
    delay_loop 6  #服务轮询的时间间隔
    lb_algo wrr  #加权轮询调度，LVS调度算法 rr|wrr|lc|wlc|lblc|sh|sh
    lb_kind DR   #LVS集群模式 NAT|DR|TUN，其中DR模式要求负载均衡器网卡必须有一块与物理网卡在同一个网段
    #nat_mask 255.255.255.0
    persistence_timeout 50  #会话保持时间
    protocol TCP  #健康检查协议

## Real Server设置，3306就是MySQL连接端口
    real_server 192.168.245.22 3306 {
        weight 3  ##权重
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
    real_server 192.168.245.33 3306 {
        weight 3
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}
```
#### 4. 启动Keepalived
```
systemctl start keeplived
```
#### 5. 查看虚拟网卡添加是否成功
```
ip a
```
* 如图会出现虚拟网卡

![](https://upload-images.jianshu.io/upload_images/21643577-b5f94beea8fd719b.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/800)

# 四、服务器192.168.245.88配置Keepalived + LVS Slave
#### 1. 安装LVS 
```
yum -y install ipvsadm
```
#### 2. 下载安装Keepalived
```
yum install -y gcc
yum install -y kernel-devel openssl openssl-devel
```
```
wget -q http://www.keepalived.org/software/keepalived-1.2.13.tar.gz
tar -zxvf keepalived-1.2.13.tar.gz
cd keepalived-1.2.13
./configure && make && make install
cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/sbin/keepalived /usr/sbin/
chkconfig --add keepalived
chkconfig --level 345 keepalived on
```
#### 3. Keepalived配置文件修改
```
vim /etc/keepalived/keepalived.conf
```
* 修改内容如下

```
! Configuration File for keepalived

global_defs {
   router_id LVS1
}

vrrp_instance VI_1 {
    state BACKUP #指定instance初始状态，实际根据优先级决定.backup节点不一样
    interface ens33 #虚拟IP所在网卡通过 ifconfig可以查看
    virtual_router_id 51 #VRID，相同VRID为一个组，决定多播MAC地址
    priority 90 #优先级，另一台改为90.backup节点不一样
    advert_int 1  #检查间隔
    authentication {
        auth_type PASS  #认证方式，可以是pass或ha
        auth_pass 1111  #认证密码
    }
    virtual_ipaddress {
        192.168.245.100  #VIP
    }
}

![](https://upload-images.jianshu.io/upload_images/21643577-3b2ab30b8a20dbb2.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

# 五、在数据服务器编写RealServer的网络配置脚本

* #### 两个数据服务器192.168.245.22和192.168.245.33进行同样操作。

#### 1.添加RealServer脚本
```
vim /etc/init.d/realserver
```
```
#!/bin/sh
VIP=192.168.245.100
. /etc/rc.d/init.d/functions

case "$1" in
# 禁用本地的ARP请求、绑定本地回环地址
start)
    /sbin/ifconfig lo down
    /sbin/ifconfig lo up
    echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
    echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
    /sbin/sysctl -p >/dev/null 2>&1
    /sbin/ifconfig lo:0 $VIP netmask 255.255.255.255 up # 在回环地址上绑定VIP，设定掩码，与Direct Server上自身的IP保持通信
    /sbin/route add -host $VIP dev lo:0
    echo "LVS-DR real server starts successfully.\n"
    ;;
stop)
    /sbin/ifconfig lo:0 down
    /sbin/route del $VIP >/dev/null 2>&1
    echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
    echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
echo "LVS-DR real server stopped.\n"
    ;;
status)
    isLoOn=`/sbin/ifconfig lo:0 | grep "$VIP"`
    isRoOn=`/bin/netstat -rn | grep "$VIP"`
    if [ "$isLoON" == "" -a "$isRoOn" == "" ]; then
        echo "LVS-DR real server has run yet."
    else
        echo "LVS-DR real server is running."
    fi
    exit 3
    ;;
*)
    echo "Usage: $0 {start|stop|status}"
    exit 1
esac
exit 0
```
#### 2. 修改脚本权限并启动realserver
```
chmod +x /etc/init.d/realserver
echo "/etc/init.d/realserver" >> /etc/rc.d/rc.local
service realserver start
```
#### 3. 查看虚拟网卡
```
ip a
``` 
* 出现虚拟网卡

![](https://upload-images.jianshu.io/upload_images/21643577-bb09b58f5960146c.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

# 六、查看LVS集群状态
```
ipvsadm -Ln
```
```
IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.245.100:3306 wrr persistent 50
  -> 192.168.245.22:3306          Route   1      0          0         
  -> 192.168.245.33:3306          Route   1      0          0  
```
# 七、测试
在WEB服务器（192.168.245.11）上，添加测试文件mysql.php
```
<?php
/**
 * Created by PhpStorm.
 * User: wen
 * Date: 7/22/2020
 * Time: 5:00 PM
 */

$servername = "192.168.245.100";
$username = "root";
$password = "123123";
$dbname = "test";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);
// 检测连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}{
    echo "连接成功";
}

$sql = "INSERT INTO activity (admin_id, user_id, name)
VALUES ('1', '122', 'keepalived1')";

if ($conn->query($sql) === TRUE) {
    echo "新记录插入成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();
?>
```
* 在浏览器访问 [http://192.168.245.11/mysql.php](http://192.168.245.11/mysql.php) 即可进行测试。

一、简介

1. Keepalived

Keepalived 是一个基于 VRRP （虚拟路由冗余协议）可用来实现服务高可用性的软件方案，避免出现单点故障。Keepalived一般用来实现轻量级高可用性，且不需要共享存储，一般用于两个节点之间，常见有LVS+Keepalived、Nginx+Keepalived组合。

2. LVS

LVS (Linux Virtual Server)是一个高可用性虚拟的服务器集群系统。本项目在1998年5月由章文嵩博士成立，是中国国内最早出现的自由软件项目之一。
LVS主要用于多服务器的负载均衡，作用于网络层。LVS构建的服务器集群系统中，前端的负载均衡层被称为Director Server；后端提供服务的服务器组层被称为Real Server。通过下图可以大致了解LVS的基础架构。
本文中将利用LVS实现MySQL的读写负载均衡，Keepalived避免节点出现单点故障。

3. MySQL双主复制

参考MySQL主主复制详细教程

二、安装配置

192.168.245.66：Keepalived + LVS Master
192.168.245.88：Keepalived + LVS Slave
192.168.245.22：MySQL Replication Master
192.168.245.33：MySQL Replication Master
192.168.245.100：VIP（虚拟IP）
192.168.245.11：Web服务器（测试用）

三、服务器192.168.245.66配置Keepalived + LVS Master

1. 安装LVS

yum -y install ipvsadm

2. 下载安装Keepalived

yum install -y gcc
yum install -y kernel-devel openssl openssl-devel

wget -q http://www.keepalived.org/software/keepalived-1.2.13.tar.gz
tar -zxvf keepalived-1.2.13.tar.gz
cd keepalived-1.2.13
./configure && make && make install
cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/sbin/keepalived /usr/sbin/
chkconfig --add keepalived
chkconfig --level 345 keepalived on

3. Keepalived配置文件修改

vim /etc/keepalived/keepalived.conf

修改内容如下

! Configuration File for keepalived

global_defs {
   router_id LVS1
}

vrrp_instance VI_1 {
    state MASTER #指定instance初始状态，实际根据优先级决定.backup节点不一样
    interface ens33 #虚拟IP所在网卡通过 ifconfig可以查看
    virtual_router_id 51 #VRID，相同VRID为一个组，决定多播MAC地址
    priority 100 #优先级，另一台改为90.backup节点不一样
    advert_int 1  #检查间隔
    authentication {
        auth_type PASS  #认证方式，可以是pass或ha
        auth_pass 1111  #认证密码
    }
    virtual_ipaddress {
        192.168.245.100  #VIP
    }
}

virtual_server 192.168.245.100 3306 {
    delay_loop 6  #服务轮询的时间间隔
    lb_algo wrr  #加权轮询调度，LVS调度算法 rr|wrr|lc|wlc|lblc|sh|sh
    lb_kind DR   #LVS集群模式 NAT|DR|TUN，其中DR模式要求负载均衡器网卡必须有一块与物理网卡在同一个网段
    #nat_mask 255.255.255.0
    persistence_timeout 50  #会话保持时间
    protocol TCP  #健康检查协议

     ## Real Server设置，3306就是MySQL连接端口
    real_server 192.168.245.22 3306 {
        weight 3  ##权重
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
    real_server 192.168.245.33 3306 {
        weight 3
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}

4. 启动Keepalived

systemctl start keeplived

5. 查看虚拟网卡添加是否成功

ip a

如图会出现虚拟网卡

四、服务器192.168.245.88配置Keepalived + LVS Slave

1. 安装LVS

yum -y install ipvsadm

2. 下载安装Keepalived

yum install -y gcc
yum install -y kernel-devel openssl openssl-devel

wget -q http://www.keepalived.org/software/keepalived-1.2.13.tar.gz
tar -zxvf keepalived-1.2.13.tar.gz
cd keepalived-1.2.13
./configure && make && make install
cp /usr/local/etc/rc.d/init.d/keepalived /etc/rc.d/init.d/
cp /usr/local/etc/sysconfig/keepalived /etc/sysconfig/
mkdir /etc/keepalived
cp /usr/local/etc/keepalived/keepalived.conf /etc/keepalived/
cp /usr/local/sbin/keepalived /usr/sbin/
chkconfig --add keepalived
chkconfig --level 345 keepalived on

3. Keepalived配置文件修改

vim /etc/keepalived/keepalived.conf

修改内容如下

! Configuration File for keepalived

global_defs {
   router_id LVS1
}

vrrp_instance VI_1 {
    state BACKUP #指定instance初始状态，实际根据优先级决定.backup节点不一样
    interface ens33 #虚拟IP所在网卡通过 ifconfig可以查看
    virtual_router_id 51 #VRID，相同VRID为一个组，决定多播MAC地址
    priority 90 #优先级，另一台改为90.backup节点不一样
    advert_int 1  #检查间隔
    authentication {
        auth_type PASS  #认证方式，可以是pass或ha
        auth_pass 1111  #认证密码
    }
    virtual_ipaddress {
        192.168.245.100  #VIP
    }
}

virtual_server 192.168.245.100 3306 {
    delay_loop 6  #服务轮询的时间间隔
    lb_algo wrr  #加权轮询调度，LVS调度算法 rr|wrr|lc|wlc|lblc|sh|sh
    lb_kind DR   #LVS集群模式 NAT|DR|TUN，其中DR模式要求负载均衡器网卡必须有一块与物理网卡在同一个网段
    #nat_mask 255.255.255.0
    persistence_timeout 50  #会话保持时间
    protocol TCP  #健康检查协议

     ## Real Server设置，3306就是MySQL连接端口
    real_server 192.168.245.22 3306 {
        weight 3  ##权重
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
    real_server 192.168.245.33 3306 {
        weight 3
        TCP_CHECK {
            connect_timeout 3
            nb_get_retry 3
            delay_before_retry 3
            connect_port 3306
        }
    }
}

4. 启动Keepalived

systemctl start keeplived

5. 查看虚拟网卡添加是否成功

ip a

由于Master上已经有虚拟网卡了，Slave上是不显示的，只有当Master出现故障时Slave才会有

五、在数据服务器编写RealServer的网络配置脚本

两个数据服务器192.168.245.22和192.168.245.33进行同样操作。

1.添加RealServer脚本

vim /etc/init.d/realserver

#!/bin/sh
VIP=192.168.245.100
. /etc/rc.d/init.d/functions

case "$1" in
# 禁用本地的ARP请求、绑定本地回环地址
start)
    /sbin/ifconfig lo down
    /sbin/ifconfig lo up
    echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
    echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
    /sbin/sysctl -p >/dev/null 2>&1
    /sbin/ifconfig lo:0 $VIP netmask 255.255.255.255 up # 在回环地址上绑定VIP，设定掩码，与Direct Server上自身的IP保持通信
    /sbin/route add -host $VIP dev lo:0
    echo "LVS-DR real server starts successfully.\n"
    ;;
stop)
    /sbin/ifconfig lo:0 down
    /sbin/route del $VIP >/dev/null 2>&1
    echo "1" >/proc/sys/net/ipv4/conf/lo/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/lo/arp_announce
    echo "1" >/proc/sys/net/ipv4/conf/all/arp_ignore
    echo "2" >/proc/sys/net/ipv4/conf/all/arp_announce
echo "LVS-DR real server stopped.\n"
    ;;
status)
    isLoOn=`/sbin/ifconfig lo:0 | grep "$VIP"`
    isRoOn=`/bin/netstat -rn | grep "$VIP"`
    if [ "$isLoON" == "" -a "$isRoOn" == "" ]; then
        echo "LVS-DR real server has run yet."
    else
        echo "LVS-DR real server is running."
    fi
    exit 3
    ;;
*)
    echo "Usage: $0 {start|stop|status}"
    exit 1
esac
exit 0

2. 修改脚本权限并启动realserver

chmod +x /etc/init.d/realserver
echo "/etc/init.d/realserver" >> /etc/rc.d/rc.local
service realserver start

3. 查看虚拟网卡

ip a

出现虚拟网卡

六、查看LVS集群状态

ipvsadm -Ln

IP Virtual Server version 1.2.1 (size=4096)
Prot LocalAddress:Port Scheduler Flags
  -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
TCP  192.168.245.100:3306 wrr persistent 50
  -> 192.168.245.22:3306          Route   1      0          0         
  -> 192.168.245.33:3306          Route   1      0          0

七、测试

在WEB服务器（192.168.245.11）上，添加测试文件mysql.php

<?php
/**
 * Created by PhpStorm.
 * User: wen
 * Date: 7/22/2020
 * Time: 5:00 PM
 */

$servername = "192.168.245.100";
$username = "root";
$password = "123123";
$dbname = "test";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);
// 检测连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}{
    echo "连接成功";
}

$sql = "INSERT INTO activity (admin_id, user_id, name)
VALUES ('1', '122', 'keepalived1')";

if ($conn->query($sql) === TRUE) {
    echo "新记录插入成功";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();
?>

在浏览器访问 http://192.168.245.11/mysql.php 即可进行测试。