Mycat与keepalived高可用

 2024/09/10 

环境说明

软件版本
mysql版本5.7.44
mycat版本1.6.7.4
linux版本CentOS7.9.2009
keepalived版本1.3.5-19(yum安装)

主机地址分配
为了避免主库与mycat使用keepalived冲突，所以mycat部署在从库上
192.168.10.125 mysql-1 master-1 
192.168.10.126 mysql-2 master-2 slave-1 (当前主库)
192.168.10.127 mysql-3 slave-2 mycat-1
192.168.10.128 mysql-4 slave-3 mycat-2
keepalived VIP 192.168.10.197/24

账号分配(测试环境)
mycat用户名admin
mycat密码admin
mysql用户root
mysql密码root

mycat部署与配置

mysql-3和mysql-4节点部署

cd /root/
wget https://github.com/MyCATApache/Mycat-Server/releases/download/Mycat-server-1.6.7.4-release/Mycat-server-1.6.7.4-release-20200105164103-linux.tar.gz
tar -xf Mycat-server-1.6.7.4-release-20200105164103-linux.tar.gz
yum -y install java
#修改配置文件
cat >/root/mycat/conf/schema.xml<<EOF
<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/">
	<schema name="db01" checkSQLschema="false" sqlMaxLimit="100" dataNode="dn1"></schema>
	<schema name="db02" checkSQLschema="false" sqlMaxLimit="100" dataNode="dn2"></schema>
	<dataNode name="dn1" dataHost="localhost1" database="ws" />
	<dataNode name="dn2" dataHost="localhost1" database="xhy" />
	<dataHost name="localhost1" maxCon="500" minCon="20" balance="1" writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
		<heartbeat>select user()</heartbeat>
		<writeHost host="master" url="192.168.10.126:3306" user="root" password="root">
			<readHost host="slave1" url="192.168.10.127:3306" user="root" password="root"/>
			<readHost host="slave2" url="192.168.10.128:3306" user="root" password="root"/>
			<readHost host="slave3" url="192.168.10.125:3306" user="root" password="root"/>
		</writeHost>
	</dataHost>
</mycat:schema>
EOF
#修改/root/mycat/conf/server.xml
        <user name="admin">
                <property name="password">admin</property>
                <property name="schemas">db01,db02</property>
                <property name="readOnly">false</property>
        </user>
#
/root/mycat/bin/mycat start
ss -tunlp | grep -c 8066
#1

keepalived配置

主mycat

yum -y install keepalived
cat >/etc/keepalived/keepalived.conf<<'EOF'
! Configuration File for keepalived
global_defs {
   router_id mysql-1
}
vrrp_script check_mycat {
    script "/etc/keepalived/check_mycat.sh"
	  interval 3
}
vrrp_instance mycat {
    state MASTER
    interface ens18
    virtual_router_id 52
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.10.197/24 dev ens18
    }
    track_script {
        check_mycat
    }
}
EOF

备mycat

yum -y install keepalived
cat >/etc/keepalived/keepalived.conf<<EOF
! Configuration File for keepalived
global_defs {
   router_id mysql-2
}
vrrp_script check_mycat {
    script "/etc/keepalived/check_mycat.sh"
	  interval 3
}
vrrp_instance mycat {
    state BACKUP
    interface ens18
    virtual_router_id 52
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.10.197/24 dev ens18
    }
    track_script {
        check_mycat
    }
}
EOF

简单检查脚本

cat >/etc/keepalived/check_mycat.sh<<'EOF'
#!/bin/bash
counter=$(ps -ef | grep mycat | grep -v grep | wc -l)  
if [ $counter -eq 0 ]; then  
    # 尝试启动 Mycat（这里需要根据你的实际启动命令修改）   
    echo "$(date +%F) 尝试重启 Mycat" >> /etc/keepalived/check.log
    /root/mycat/bin/mycat start 2>&1 /dev/null
    sleep 2
    counter=$(ps -ef | grep mycat | grep -v grep | wc -l)   
    if [ $counter -eq 0 ]; then 
		    echo "$(date +%F) mycat重启失败，关闭keepalived" >> /etc/keepalived/check.log
        systemctl stop keepalived
        echo "$(hostname) 主机 Mycat 服务异常，vip 已切换" | mail -s "keepalived 告警" alertwarning@163.com  
    fi
fi
EOF

chmod +x /etc/keepalived/check_mycat.sh

测试VIP漂移

systemctl daemon-reload
systemctl restart keepalived.service
systemctl is-active keepalived.service
#active

此时已经有VIP了
mysql-3:
ip a | grep 192
    inet 192.168.10.127/24 brd 192.168.10.255 scope global noprefixroute ens18
    inet 192.168.10.197/24 scope global secondary ens18
mysql-4:
ip a| grep 192
    inet 192.168.10.128/24 brd 192.168.10.255 scope global noprefixroute ens18

并且能够连接成功

关闭mysql-3的keepalived
systemctl stop keepalived.service
ip a | grep 192.
    inet 192.168.10.127/24 brd 192.168.10.255 scope global noprefixroute ens18
ip a| grep 192
    inet 192.168.10.128/24 brd 192.168.10.255 scope global noprefixroute ens18
    inet 192.168.10.197/24 scope global secondary ens18