安装jdk 1.8
[root@proxy ~]# yum localinstall jdk-8u261-linux-x64.rpm -y
[root@proxy ~]# java -version
java version "1.8.0_261"
Java(TM) SE Runtime Environment (build 1.8.0_261-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.261-b12, mixed mode)

# 下载软件包
[root@proxy ~]# wget -c http://dl.mycat.org.cn/2.0/install-template/mycat2-install-template-1.21.zip
[root@proxy ~]# wget -c http://dl.mycat.org.cn/2.0/1.21-release/mycat2-1.21-release-jar-with-dependencies.jar

1、解压安装包
[root@proxy ~]# yum install unzip -y
[root@proxy ~]# unzip mycat2-install-template-1.21.zip -d /usr/local/

2、复制jar到mycat/lib目录
[root@proxy ~]# cp mycat2-1.21-release-jar-with-dependencies.jar /usr/local/mycat/lib/

把bin目录的文件加执行权限
[root@proxy ~]# cd /usr/local/mycat/bin/
[root@proxy bin]# chmod +x *

[root@proxy ~]# ll /usr/local/mycat/
total 8
drwxr-xr-x 2 root root 4096 Mar  5  2021 bin		# 执行命令的目录
drwxr-xr-x 9 root root  275 Mar  5  2021 conf		# 配置文件目录
drwxr-xr-x 2 root root 4096 Jan  6 10:08 lib		# 依赖包
drwxr-xr-x 2 root root    6 Mar  5  2021 logs		# 日志包

1、安装mysql
[root@proxy ~]# yum install mysql-server -y

2、启动mysql
# systemctl enable --now mysqld

3、修改root密码
# mysqladmin -uroot password '123456'

4、添加mycat用户
# 注意：MySQL 8.0 主从同步mycat 连接账号设置
# 本文使用mycat用户连接
master上创建用户：
CREATE USER 'mycat'@'%' IDENTIFIED WITH mysql_native_password BY '123456';
--必须要赋的权限mysql8才有的
GRANT XA_RECOVER_ADMIN ON *.* TO 'mycat'@'%';
---视情况赋权限
GRANT ALL PRIVILEGES ON *.* TO 'mycat'@'%' ;
flush privileges;

[root@proxy ~]# vim /usr/local/mycat/conf/datasources/prototypeDs.datasource.json
{
        "dbType":"mysql",
        "idleTimeout":60000,
        "initSqls":[],
        "initSqlsGetConnection":true,
        "instanceType":"READ_WRITE",
        "maxCon":1000,
        "maxConnectTimeout":3000,
        "maxRetryCount":5,
        "minCon":1,
        "name":"prototypeDs",
        "password":"123456",
        "type":"JDBC",
        "url":"jdbc:mysql://localhost:3306/mysql?useUnicode=true&serverTimezone=Asia/Shanghai&characterEncoding=UTF-8",
        "user":"mycat",
        "weight":0
}

[root@proxy ~]# cd /usr/local/mycat/bin/
[root@proxy bin]# ./mycat start
Starting mycat2...
[root@proxy bin]# ./mycat status
mycat2 is running (3934).

管理端口9066
1、登录数据端口
数据端口8066
[root@proxy ~]# mysql -uroot -p123456 -P8066 -h192.168.1.51
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.33-mycat-2.0 MySQL Community Server (GPL)

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

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

MySQL [(none)]> show databases;
+--------------------+
| `Database`         |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
+--------------------+
3 rows in set (0.31 sec)

MySQL [(none)]> \q
Bye

# cat /usr/local/mycat/conf/users/root.user.json 
{
	"dialect":"mysql",
	"ip":null,
	"password":"123456",
	"transactionType":"proxy",
	"username":"root"
}

# cat /data/mycat/conf/datasources/prototypeDs.datasource.json 
{
	"dbType":"mysql",
	"idleTimeout":60000,
	"initSqls":[],
	"initSqlsGetConnection":true,
	"instanceType":"READ_WRITE",
	"maxCon":1000,
	"maxConnectTimeout":3000,
	"maxRetryCount":5,
	"minCon":1,
	"name":"prototypeDs",
	"password":"123456",
	"type":"JDBC",
	"url":"jdbc:mysql://localhost:3306?useUnicode=true&serverTimezone=Asia/Shanghai&characterEncoding=UTF-8",
	"user":"root",
	"weight":0
}

{	
	"customTables": {},	
	"globalTables": {},	
	"normalTables": {},	
	"schemaName": "test",	
	"shardingTables": {},	
	"targetName": "prototype"
}

/*+ mycat:resetConfig{} */

/*+ mycat:createUser{ 
  "username":"user", 
  "password":"", 
  "ip":"127.0.0.1", 
  "transactionType":"xa"} 
*/

/*+ mycat:dropUser{ "username":"user"} */

/*+ mycat:showUsers */

/*+ mycat:createDataSource{ 
  "dbType":"mysql", 
  "idleTimeout":60000, 
  "initSqls":[], 
  "initSqlsGetConnection":true, 
  "instanceType":"READ_WRITE", 
  "maxCon":1000, 
  "maxConnectTimeout":3000, 
  "maxRetryCount":5, 
  "minCon":1, 
  "name":"dc1",
  "password":"123456",
  "type":"JDBC",
  "url":"jdbc:mysql://127.0.0.1:3306?useUnicode=true&serverTimezone=UTC&characterEncoding=UTF-8",
  "user":"root",
  "weight":0} 
*/;

/*+ mycat:dropDataSource{
  "dbType":"mysql", 
  "idleTimeout":60000, 
  "initSqls":[], 
  "initSqlsGetConnection":true, 
  "instanceType":"READ_WRITE", 
  "maxCon":1000, 
  "maxConnectTimeout":3000, 
  "maxRetryCount":5, 
  "minCon":1, 
  "name":"dc1",
  "type":"JDBC", 
  "weight":0} 
*/;

/*+ mycat:showDataSources{} */

先创建两个数据源dc1和dc2，然后创建集群，dc1是主节点

/*! mycat:createCluster{
	"clusterType":"MASTER_SLAVE",
	"heartbeat":{
		"heartbeatTimeout":1000,
		"maxRetry":3,
		"minSwitchTimeInterval":300,
		"slaveThreshold":0
	},
	"masters":[
		"dc1" //主节点
	],
	"maxCon":200,
	"name":"c0",
	"readBalanceType":"BALANCE_ALL",
	"replicas":[
		"dc2" //从节点
	],
	"switchType":"SWITCH"
} */

/*! mycat:dropCluster{ "name":"c0"} */;

/*+ mycat:showClusters{} */

[root@proxy ~]# mysql -uroot -p123456 -P8066 -h192.168.150.24
#在Mycat里创建数据库mydb1
#创建db2逻辑库
create database mydb1;

#修改mydb1.schema.json 指定数据源 "targetName": "prototype"，配置主机数据源
[root@proxy ~]# vim /usr/local/mycat/conf/schemas/mydb1.schema.json 
{
        "customTables":{},
        "globalTables":{},
        "normalProcedures":{},
        "normalTables":{},
        "schemaName":"mydb1",
        "targetName":"prototype",
        "shardingTables":{},
        "views":{}
}

#登录Mycat，注解方式添加数据源，指向从机
/*+ mycat:createDataSource{
"name":"rwSepw",
"url":"jdbc:mysql://172.16.100.21:3306/?useSSL=false&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true",
"user":"mycat",
"password":"123456"
} */

/*+ mycat:createDataSource{
"name":"rwSepr1",
"url":"jdbc:mysql://172.16.100.22:3306/?useSSL=false&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true",
"user":"mycat",
"password":"123456"
} */

/*+ mycat:createDataSource{
"name":"rwSepr2",
"url":"jdbc:mysql://172.16.100.23:3306/?useSSL=false&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true",
"user":"mycat",
"password":"123456"
} */

#查询配置数据源结果
/*+ mycat:showDataSources{} */;

#更新集群信息,添加dr0从节点.
/*!mycat:createCluster{"name":"prototype","masters":["rwSepw"],"replicas":["rwSepr1","rwSepr2"]} */;
#查看配置集群信息
/*+ mycat:showClusters{} */;
#查看集群配置文件
[root@proxy ~]# cat /usr/local/mycat/conf/clusters/prototype.cluster.json
{
        "clusterType":"MASTER_SLAVE",
        "heartbeat":{
                "heartbeatTimeout":1000,
                "maxRetryCount":3,
                "minSwitchTimeInterval":300,
                "showLog":false,
                "slaveThreshold":0.0
        },
        "masters":[
                "rwSepw"
        ],
        "maxCon":2000,
        "name":"prototype",
        "readBalanceType":"BALANCE_ALL",
        "replicas":[
                "rwSepr1",
                "rwSepr2"
        ],
        "switchType":"SWITCH"
}

readBalanceType
查询负载均衡策略
可选值:
BALANCE_ALL(默认值)
获取集群中所有数据源
BALANCE_ALL_READ
获取集群中允许读的数据源
BALANCE_READ_WRITE
获取集群中允许读写的数据源,但允许读的数据源优先
BALANCE_NONE
获取集群中允许写数据源,即主节点中选择
switchType
NOT_SWITCH:不进行主从切换
SWITCH:进行主从切换

[root@proxy ~]# cd /usr/local/mycat/bin/
[root@proxy bin]# ./mycat restart
Stopping mycat2...
Stopped mycat2.
Starting mycat2...
[root@proxy bin]# ./mycat status
mycat2 is running (15547).

[root@proxy ~]# mysql -uroot -p123456 -P8066 -h192.168.150.24

CREATE DATABASE db1 DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci;

use db1
create table sys_user(
    id bigint primary key,
    username varchar(200) not null,
    address  varchar(500)
);

/*+ mycat:repairPhysicalTable{} */;

insert INTO sys_user(id,username,address) values(1,"xiaofang","wuhan");

mysql> select @@hostname;
+------------+
| @@hostname |
+------------+
| master     |
+------------+
1 row in set (0.00 sec)

mysql> update db1.sys_user
    -> set address="wuhan_master";
Query OK, 1 row affected (0.01 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select @@hostname;
+------------+
| @@hostname |
+------------+
| slave1     |
+------------+
1 row in set (0.00 sec)

mysql> update db1.sys_user
    ->  set address="wuhan_slave1";
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select @@hostname;
+------------+
| @@hostname |
+------------+
| slave2     |
+------------+
1 row in set (0.00 sec)

mysql> update db1.sys_user
    -> set address="wuhan_slave2";
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

[root@proxy ~]# mysql -uroot -p123456 -P8066 -h192.168.150.24 -e "select * from db1.sys_user"
mysql: [Warning] Using a password on the command line interface can be insecure.
+----+----------+--------------+
| id | username | address      |
+----+----------+--------------+
|  1 | xiaofang | wuhan_slave1 |
+----+----------+--------------+
[root@proxy ~]# mysql -uroot -p123456 -P8066 -h192.168.150.24 -e "select * from db1.sys_user"
mysql: [Warning] Using a password on the command line interface can be insecure.
+----+----------+--------------+
| id | username | address      |
+----+----------+--------------+
|  1 | xiaofang | wuhan_slave2 |
+----+----------+--------------+
[root@proxy ~]# mysql -uroot -p123456 -P8066 -h192.168.150.24 -e "select * from db1.sys_user"
mysql: [Warning] Using a password on the command line interface can be insecure.
+----+----------+--------------+
| id | username | address      |
+----+----------+--------------+
|  1 | xiaofang | wuhan_master |
+----+----------+--------------+