搭建MyCat2双主双从的MySQL读写分离

搭建MyCat2读写分离

搭建MySQL双主双从复制

搭建MySQL双主双从复制参考：在Windows环境与Linux环境下搭建MySQL主从同步

1.做好双主双从的MySQL中有mydb这个库,且已经存在表和数据

2.登录主库1：mysql -h localhost -P3306 -uroot -p

mysql> CREATE DATABASE mydb;
Query OK, 1 row affected (0.00 sec)

mysql> use mydb;
Database changed
mysql> CREATE TABLE mytb(id INT,name VARCHAR(30));
Query OK, 0 rows affected (0.02 sec)

mysql> INSERT INTO mytb VALUES(1,'mycat');
Query OK, 1 row affected (0.01 sec)

2.登录主库2：mysql -h localhost -P3307 -uroot -p

mysql> use mydb;
Database changed
mysql> select * from mytb;
+------+---------+
| id   |  name   |
+------+---------+
|    1 |  mycat	 |
+------+---------+
1 row in set (0.00 sec)

3.登录从库1：mysql -h localhost -P3308 -uroot -p

mysql> use mydb;
Database changed
mysql> select * from mytb;
+------+---------+
| id   |  name   |
+------+---------+
|    1 |  mycat	 |
+------+---------+
1 row in set (0.00 sec)

4.登录从库2：mysql -h localhost -P3309 -uroot -p

mysql> use mydb;
Database changed
mysql> select * from mytb;
+------+---------+
| id   |  name   |
+------+---------+
|    1 |  mycat	 |
+------+---------+
1 row in set (0.00 sec)

安装MyCat2

安装MyCat2参考：MyCat2的介绍与安装以及基本使用

逻辑库配置

登录Mycat：mysql -uroot -p123456 -h localhost -P 8066，创建逻辑库

mysql> create database mydb;
Query OK, 1 row affected (0.00 sec)

执行create database mydb;后，将在/mycat/conf/schemas/自动生成mydb.schema.json文件

{
    
	"customTables":{
    },
	"globalTables":{
    },
	"normalProcedures":{
    },
	"normalTables":{
    },
	"schemaName":"mydb",
	"shardingTables":{
    },
	"views":{
    }
}

customTables：mycat默认的表的配置

globalTables：全局表的配置

shardingTables：分片表的配置

normalTables：普通表的配置

修改schema的配置，指定mydb逻辑库默认的targetName，mycat会自动加载mydb下已经有的物理表或者视图作为单表

{
    
	"customTables":{
    },
	"globalTables":{
    },
	"normalProcedures":{
    },
	"normalTables":{
    },
	"schemaName":"mydb",
	"targetName":"prototype"
	"shardingTables":{
    },
	"views":{
    }
}

查看修改之后的schema的配置，发现已经自动加载了相关信息到normalTables中

{
    
	"customTables":{
    },
	"globalTables":{
    },
	"normalProcedures":{
    },
	"normalTables":{
    
		"mytb":{
    
			"createTableSQL":"CREATE TABLE `mydb`.`mytb` (\n\t`id` int(11) DEFAULT NULL,\n\t`name` varchar(30) DEFAULT NULL\n) ENGINE = InnoDB CHARSET = utf8",
			"locality":{
    
				"schemaName":"mydb",
				"tableName":"mytb",
				"targetName":"prototype"
			}
		}
	},
	"schemaName":"mydb",
	"shardingTables":{
    },
	"views":{
    }
}

登录Mycat：mysql -uroot -p123456 -h localhost -P 8066，进行查询

mysql> use mydb;
Database changed
mysql> SELECT * FROM mytb;
+------+-------+
| id   | name  |
+------+-------+
|    1 | mycat |
+------+-------+
1 row in set (0.03 sec)

添加数据源

添加Master1数据源

/*+ mycat:createDataSource{ "name":"write1","url":"jdbc:mysql://112.74.96.150:3306/mydb?useSSL=false&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true", "user":"mycat","password":"123456" } */;

添加Master2数据源

/*+ mycat:createDataSource{ "name":"write2","url":"jdbc:mysql://112.74.96.150:3307/mydb?useSSL=false&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true", "user":"root","password":"123456" } */;

添加Slave1数据源

 /*+ mycat:createDataSource{ "name":"red1","url":"jdbc:mysql://112.74.96.150:3308/mydb?useSSL=false&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true", "user":"root","password":"123456" } */;

添加Slave2数据源

/*+ mycat:createDataSource{ "name":"red2","url":"jdbc:mysql://112.74.96.150:3309/mydb?useSSL=false&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true", "user":"root","password":"123456" } */;

查询配置数据源结果

/*+ mycat:showDataSources{} */;

通过注释命名添加数据源后，在对应目录会生成相关配置文件，查看数据源配置文件：mycat/conf/datasources

[root@administrator mycat]#  ls conf/datasources
prototypeDs.datasource.json  red2.datasource.json    write2.datasource.json
red1.datasource.json         write1.datasource.json

更新集群配置

使用mycat自带的默认集群:prototype，对其修改更新即可

 /*! mycat:createCluster{"name":"prototype","masters":["write1","write2"],"replicas":["red1","red2","write2"]} */;

查看配置集群信息

/*+ mycat:showClusters{} */;

查看集群配置文件，发现集群配置信息已经更新

vim /usr/local/mycat/conf/clusters/prototype.cluster.json

{
    
	"clusterType":"MASTER_SLAVE",
	"heartbeat":{
    
		"heartbeatTimeout":1000,
		"maxRetryCount":3,
		"minSwitchTimeInterval":300,
		"showLog":false,
		"slaveThreshold":0.0
	},
	"masters":[
		"write1",
		"write2"
	],
	"maxCon":2000,
	"name":"prototype",
	"readBalanceType":"BALANCE_ALL",
	"replicas":[
		"red1",
		"red2",
		"write2"
	],
	"switchType":"SWITCH"
}

readBalanceType：查询负载均衡策略

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：控制主从切换

NOT_SWITCH:不进行主从切换

SWITCH:进行主从切换

此时，架构如下

验证读写分离

修改MySQL的配置文件：my.cnf，设置logbin格式binlog_format=STATEMENT，重启MySQL，确保此时主从复制正常

登录MyCat：mysql -uroot -p123456 -h IP -P 8066，向数据表插入系统变量值，以此造成主从数据不一致，便于验证读写分离。

mysql> use mydb;
Database changed
mysql> INSERT INTO mytb VALUES(2,@@hostname);

登录双主双从MySQL4个库查看表数据

mysql -uroot -h IP  -P 3306 -p
mysql -uroot -h IP  -P 3307 -p
mysql -uroot -h IP  -P 3308 -p
mysql -uroot -h IP  -P 3309 -p

登录MyCat：mysql -uroot -p123456 -h IP -P 8066，查询验证

mysql> use mydb;
Database changed
mysql> SELECT * FROM mytb;
+------+--------------+
| id   | name         |
+------+--------------+
|    1 | mycat        |
|    2 | 3cf0d174674d |
+------+--------------+
2 rows in set (0.01 sec)

mysql> SELECT * FROM mytb;
+------+--------------+
| id   | name         |
+------+--------------+
|    1 | mycat        |
|    2 | 5990c4387bd9 |
+------+--------------+
2 rows in set (0.00 sec)

mysql> SELECT * FROM mytb;
+------+--------------+
| id   | name         |
+------+--------------+
|    1 | mycat        |
|    2 | 4e4f0d81922a |
+------+--------------+
2 rows in set (0.00 sec)

mysql> SELECT * FROM mytb;
+------+---------------+
| id   | name          |
+------+---------------+
|    1 | mycat         |
|    2 | administrator |
+------+---------------+
2 rows in set (0.01 sec)

mysql> SELECT * FROM mytb;
+------+--------------+
| id   | name         |
+------+--------------+
|    1 | mycat        |
|    2 | 5990c4387bd9 |
+------+--------------+
2 rows in set (0.00 sec)