[root@localhost ~]# mkdir /usr/java
[root@localhost ~]# tar xf jdk-8u311-linux-x64.tar.gz -C /usr/java/

2）、设置环境变量

[root@localhost ~]# vi /etc/profile.d/java.sh
[root@localhost ~]# cat /etc/profile.d/java.sh
export JAVA_HOME=/usr/java/jdk1.8.0_311/
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

使环境变量生效

[root@localhost ~]# source /etc/profile.d/java.sh

3）、测试

[root@localhost ~]# java -version
java version "1.8.0_311"
Java(TM) SE Runtime Environment (build 1.8.0_311-b11)
Java HotSpot(TM) 64-Bit Server VM (build 25.311-b11, mixed mode)

2、下载文件

1）、下载对应的tar安装包,以及对应的jar包

[root@localhost ~]# wget -c http://dl.mycat.org.cn/1.6.5/Mycat-server-1.6.5-release-20180122220033-linux.tar.gz

2）、解压

[root@localhost ~]# tar -xf Mycat-server-1.6.5-release-20180122220033-linux.tar.gz -C /usr/local/

3）、添加环境变量

[root@localhost ~]# cd /usr/local/
[root@localhost local]# echo "export PATH=$PATH:/usr/local/mycat/bin" > /etc/profile.d/mycat.sh
[root@localhost local]# source /etc/profile.d/mycat.sh

4）、准备环境（一主一从都执行如下操作初始化MySQL，rpm安装的MySQL可用）

[root@localhost ~]# systemctl stop mysqld
[root@localhost ~]# rm -rf /var/lib/mysql/* 
[root@localhost ~]# mysqld --initialize --datadir=/var/lib/  //初始化
[root@localhost ~]# systemctl start mysqld
[root@localhost ~]# grep -i password /var/log/mysqld.log   //查找初始化后的密码

5)、配置主从

主库

mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |      154 |              | sys,mysql        |                   |
+------------------+----------+--------------+------------------+-------------------+#创建用户
mysql> grant replication slave on *.* to rep@'192.168.159.%' identified by '123456';#指定不需要同步的数据库
[root@localhost ~]# vi /etc/my.cnf
binlog_ignore_db=sys
binlog_ignore_db=mysql[root@localhost ~]# systemctl restart mysqld

从库

mysql> change master to -> master_host='192.168.159.135', -> master_user='rep', -> master_password='123456' , -> MASTER_AUTO_POSITION=0;mysql> start slave;   mysql> show slave status \G   #两个都为yes即可Slave_IO_Running: YesSlave_SQL_Running: Yes

6、配置读写分离

1）、mycat端修改配置文件

[root@localhost ~]# cd /usr/local/mycat/conf/[root@localhost conf]# cp schema.xml{,.bak}[root@localhost conf]# vim schema.xml<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/"><schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100" dataNode="dn1"></schema><dataNode name="dn1" dataHost="localhost1" database="db1" /><dataHost name="localhost1" maxCon="1000" minCon="10" balance="1"writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100"><heartbeat>select user()</heartbeat><writeHost host="hostM1" url="192.168.159.135:3306" user="mycat"password="123456"><readHost host="hostS2" url="192.168.159.134:3306" user="mycat_r" password="123456" /></writeHost></dataHost>
</mycat:schema>

2)、主库创建db1数据库

mysql> create database db1;

3）、创建用户

mysql> grant insert,delete,update,select on db1.* to mycat@'192.168.159.%' identified by '123456';

mysql> grant select on db1.* to mycat_r@'192.168.159.%' identified by '123456';

mysql> use db1
mysql> CREATE TABLE test1 (id int(10),name varchar(10),address varchar(20) DEFAULT NULL);

管理端插入数据：

mysql> insert into test1 values(1,'test1','master');
mysql> insert into test1 values(2,'test1','slave1');
mysql> insert into test1 values(3,'test1','slave2');

验证：

管理端登录9066端口

[root@localhost ~]# mysql -uroot -p123456 -P9066 -DTESTDB -h192.168.159.136mysql> show @@database;   #显示mycat数据库的列表，对应的在scehma.xml配置的逻辑库
+----------+
| DATABASE |
+----------+
| TESTDB   |
+----------+mysql> show @@datanode;  #）显示mycat数据节点的列表，对应的是scehma.xml配置文件的dataNode节点
+------+----------------+-------+-------+--------+------+------+---------+------------+----------+---------+---------------+
| NAME | DATHOST        | INDEX | TYPE  | ACTIVE | IDLE | SIZE | EXECUTE | TOTAL_TIME | MAX_TIME | MAX_SQL | RECOVERY_TIME |
+------+----------------+-------+-------+--------+------+------+---------+------------+----------+---------+---------------+
| dn1  | localhost1/db1 |     0 | mysql |      0 |   10 | 1000 |     139 |          0 |        0 |       0 |            -1 |
+------+----------------+-------+-------+--------+------+------+---------+------------+----------+---------+---------------+ysql> show @@heartbeat;  #查看心跳检测
+--------+-------+-----------------+------+---------+-------+--------+---------+--------------+---------------------+-------+
| NAME   | TYPE  | HOST            | PORT | RS_CODE | RETRY | STATUS | TIMEOUT | EXECUTE_TIME | LAST_ACTIVE_TIME    | STOP  |
+--------+-------+-----------------+------+---------+-------+--------+---------+--------------+---------------------+-------+
| hostM1 | mysql | 192.168.159.135 | 3306 |       1 |     0 | idle   |       0 | 2,2,2        | 2022-01-30 23:11:32 | false |
| hostS2 | mysql | 192.168.159.134 | 3306 |       1 |     0 | idle   |       0 | 1,2,2        | 2022-01-30 23:11:32 | false |
+--------+-------+-----------------+------+---------+-------+--------+---------+--------------+---------------------+-------+

查看所有的命令

mysql> show @@help;

获取当前mycat的版本

mysql> show @@version;

显示mycat前端连接状态

mysql> show @@connection;

显示mycat后端连接状态

mysql> show @@backend;

显示数据源

mysql> show @@datasource