搭建MyCat2一主一从的MySQL读写分离
搭建MyCat2一主一从的MySQL读写分离
- 搭建MyCat2读写分离
-
- 搭建MySQL主从复制
- 安装MyCat2
- 配置逻辑库
- 添加数据源
- 更新集群配置
- 验证读写分离
搭建MyCat2读写分离
通过Mycat2与MySQL的主从同步复制配合就可以搭建MySQL数据库的读写分离，这里搭建MyCat2一主一从的MySQL读写分离。
搭建MySQL主从复制
搭建MySQL主从复制参考：在Windows环境与Linux环境下搭建MySQL主从同步
1.做好主从的MySQL中有mydb这个库,且已经存在表和数据
2.登录主库：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)
3.登录从库：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)
安装MyCat2
安装MyCat2参考：MyCat2的介绍与安装以及基本使用
配置逻辑库
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)
此时，架构如下：
添加数据源
登录Mycat：mysql -uroot -p123456 -h localhost -P 8066，使用注解方式添加数据源
添加主库数据源
mysql> /*+ mycat:createDataSource{ "name":"write","url":"jdbc:mysql://IP:3306/mydb?useSSL=false&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true", "user":"mycat","password":"123456" } */;
Query OK, 0 rows affected (0.00 sec)
添加从库数据源
mysql> /*+ mycat:createDataSource{ "name":"red","url":"jdbc:mysql://IP:3307/mydb?useSSL=false&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true", "user":"root","password":"123456" } */;
Query OK, 0 rows affected (0.00 sec)
查询配置数据源结果
mysql> /*+ mycat:showDataSources{} */;
Query OK, 0 rows affected (0.00 sec)
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 red.datasource.json write.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":["write"],"replicas":["red"]} */;
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":[
"write"
],
"maxCon":2000,
"name":"prototype",
"readBalanceType":"BALANCE_ALL",
"replicas":[
"red"
],
"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);
登录主库：mysql -uroot -h IP -P 3306 -p查看表数据
mysql> SELECT * FROM mytb;
+------+---------------+
| id | name |
+------+---------------+
| 1 | mycat |
| 2 | administrator |
+------+---------------+
2 rows in set (0.01 sec)
登录从库：mysql -uroot -h IP -P 3307 -p查看表数据
mysql> use mydb;
Database changed
mysql> select * from mytb;
+------+--------------+
| id | name |
+------+--------------+
| 1 | mycat |
| 2 | 5990c4387bd9 |
+------+--------------+
2 rows
登录MyCat：mysql -uroot -p123456 -h IP -P 8066，查询验证
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 (0.01 sec)