一：环境准备：
| 应用 | 主机 |
|---|---|
| mysql-master | 192.168.205.184 |
| mysql-slave | 192.168.205.185 |
| mycat-01,keeplived,jdk | 192.168.205.182 |
| mycat-02,keeplived,jdk | 192.168.205.183 |
mysql主从环境（略）
二: 主机（192.168.205.183，192.168.205.182）上安装jdk，mycat，keeplived
以192.168.205.183主机为例，另外一台主机配置与183主机一致：
1.安装jdk
上传jdk安装包解压安装到/usr/local/jdk
vim /etc/profile
export JAVA_HOME=/usr/local/jdk
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
export PATH=$JAVA_HOME/bin:$PATH . /etc/profile
2.官网下载安装mycat
wget http://dl.mycat.org.cn/1.6.7.4/Mycat-server-1.6.7.4-release/Mycat-server-1.6.7.4-release-20200105164103-linux.tar.gz
tar -zxvf Mycat-server-1.6.7.4-release-20200105164103-linux.tar.gz
mv mycat/ /opt/
3.修改配置文件
cd /opt/mycat/conf
vim server.xml 
vim schema.xml
4.启动mycat服务
cd /opt/mycat/bin
./mycat start
mycat启动后会有2个端口8066（数据连接端口），9066（管理端口）
ss -ntupl
5.通过mysql客户端连接8066（我们在mysql-master节点登录mycat试下）
mysql -ulilong -p111111 -P8066 -h 192.168.205.183
6.查看mycat里数据库信息
7.进入TSDB创建表city
crate table city(id int,name varchar(8),area float(5,2),people_num int);
查看数据库中是否创建成功
show tables;
在2台数据库节点看是否已存在此表（由于做了读写分离在创建表时走了写节点也就是主库，从库也同步过来了）
8.通过mysql客户端连接9066可以查看到相关dataNode信息
mysql -ulilong -p111111 -P9066 -h 192.168.205.183
show @@dataNode;
在2台mycat节点上安装keepalived并单独配置日志文件（默认在/var/log/messages日志查看不方便）
192.168.205.182:
yum -y install keepalived
vim /etc/sysconfig/keepalived
KEEPALIVED_OPTIONS="-D -d -S 0"
vim /etc/rsyslog.conf
local0.* /var/log/keepalived.log
systemctl restart rsyslog
vim /etc/keepalived/keepalived.conf
192.168.205.183:
yum -y install keepalived
vim /etc/sysconfig/keepalived
KEEPALIVED_OPTIONS="-D -d -S 0"
vim /etc/rsyslog.conf
local0.* /var/log/keepalived.log
systemctl restart rsyslog
vim /etc/keepalived/keepalived.conf
分别启动2节点keepalived
192.168.205.182:
systemctl start keepalived
可以看到vip接口在182节点上
192.168.205.183:
systemctl start keepalived
在mysql节点上我们通过vip接口登录试下
mysql -ulilong -p111111 -P8066 -h 192.168.205.250
下图我们看到已经登录成功
我们停用192.168.205.182的keepalived试下看是否转移到192.168.205.183上
可以看到182节点vip接口不在了
在看下183节点vip接口已飘逸到此节点上
我们再次启动主节点上keepalived发现vip接口已经飘逸回来，默认情况下keepalived是抢占模式所以主节点恢复后会直接抢占回来
到此为止基本完成配置，可仔细想想如果是所在keepalived的master节点mycat服务有问题那它还会切换到备用节点吗。答案肯定是否定的。这就需要在keepalived 配置脚本来检测mycat服务状态如果所在节点master的mycat服务挂掉了， 那就主动结束所在master节点的keepalived进程切换至备用节点继续提供服务
2节点分别创建存放脚本的文件
mkdir -p /etc/keepalived/scripts
vim /etc/keepalived/scripts/chk_mycat.sh
#!/bin/bash
MYCAT_PORT=
ss -ntupl | egrep '8066|9066' | wc -l
if [ $MYCAT_PORT -ne 2 ];then
pkill keepalived
fi
在 /etc/keepalived/keepalived.conf配置文件中将以下内容加入到相应位置
vrrp_script chk_mycat {
script "/etc/keepalived/scripts/chk_mycat.sh"
interval 2
weight -50
fall 3
rise 3
timeout 3
}
track_script {
chk_mycat
}
重新启动keepalived服务
systemctl restart keepalived
验证检测脚本是否生效：
将master节点上mycat服务手动停掉
cd /opt/mycat/bin && ./mycat stop
此时master节点keepalived服务已经停止了
在看下backup节点，发现vip已经飘移到此节点上
从mysql客户端访问正常
配置MASTER<-->slave 相互切换时邮件通知
2个keepalived节点安装postfix邮件服务（默认已安装）和 发送邮件插件mailx
yum -y install mailx
vim /etc/mail.rc
set smtp=smtp.exmail.qq.com
set smtp-auth-password=***
smtp-auth=login
将以下配置加入下面相应位置（2台做同样操作）
MASTER，BACKUP，FAULT（大小写均可）
vim /etc/keepalived/keepalived.conf
notify_master "/etc/keepalived/scripts/notify.sh MASTER"
notify_backup "/etc/keepalived/scripts/notify.sh BACKUP"
notify_fault "/etc/keepalived/scripts/notify.sh FAULT"
创建相应脚本文件(2台做同样操作)
cd /etc/keepalived/scripts
vim notify.sh
#!/bin/bash
SEND_to_MAIL='[email protected]'
notify() {
MAIL_SUBJECT="$(hostname) to be $1, vip 转移"
MAIL_TEXT="$(date +'%F %T'): vrrp transition, $(hostname) changed to be $1"
echo "$MAIL_TEXT" | mail -s "$MAIL_SUBJECT" $SEND_to_MAIL
}
case $1 in
MASTER)
notify MASTER
;;
BACKUP)
notify BACKUP
;;
FAULT)
notify FAULT
;;
*)
echo "Usage: $(basename $0) {MASTER|BACKUP|FAULT}"
exit 1
;;
esac
更改脚本执行权限
chmod +x notify
重新启动keepalived服务
systemctl restart keepalived
已可以看到vip已转移到备用节点上
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mycat分表
1.我们以2个dataNode节点为例子在mysql-master库上新建cs1_db，mysql-slave会同步cs1_db库，之前已建过cs_db库，在2个库里分别新建表'wuhan'
2.mycat节点（2台分表做以下配置）
vim schema.xml
vim rule.xml
3.重启mycat服务
cd /opt/mycat/bin && ./mycat restart
4.通过VIP接口连接mycat服务，插入数据
mysql -ulilong -p111111 -P8066 -h 192.168.205.250
insert into wuhan(id,address) values(7,'xx'),(8,'xg'),(9,'lx'),(10,'ob'),(11,'kx'),(12,'hx');
5.查看2个数据库wuhan表中数据，发现数据已经分表插入到了2个数据库中同一表里
6.可以看下mysql-slave库也同步了
到此所有配置已结束