简单了解mysql mycat 中间件

# tar zxvf Mycat-server-1.6-RELEASE-20161028204710-linux.tar.gz -C /usr/local/ 

# vim /usr/local/mycat/conf/server.xml //添加以下内容 
<user name="user"> //mycat用户名 
<property name="password">user</property> //mycat密码 
<property name="schemas">mytest</property> //mycat虚拟数据库名 
<property name="readOnly">true</property> //只读 
</user> 
<user name="tankzhang"> 
<property name="password">admin</property> 
<property name="schemas">mytest</property> 
</user> 

# cat schema.xml 
<?xml version="1.0"?> 
<!DOCTYPE mycat:schema SYSTEM "schema.dtd"> 
<mycat:schema xmlns:mycat="http://io.mycat/"> 
<schema name="mytest" checkSQLschema="false" sqlMaxLimit="100" dataNode="my1" />//定义虚拟数据库名mytest 
<dataNode name="my1" dataHost="test1" database="test" /> //真实数据库名test 
<dataHost name="test1" maxCon="1000" minCon="10" balance="1" writeType="0" dbType="mysql" dbDriver="native" > 
<heartbeat>select user()</heartbeat> 
<writeHost host="hostM1" url="192.168.5.213:3306" user="tank" password="123456" > //真实数据库的连接方式 
<readHost host="hostS1" url="192.168.5.214:3306" user="tank" password="123456" /> //同上 
</writeHost> 
</dataHost> 
</mycat:schema> 

grant all privileges on test.* to tank@"192.168.%" identified by '123456'; 
flush privileges 

./mycat start 启动 
./mycat stop 停止 
./mycat console 前台运行 
./mycat restart 重启服务 
./mycat pause 暂停 
./mycat status 查看启动状态 

# ./mycat start 
Starting Mycat-server... 
# netstat -tpnl |grep 8066 
tcp 0 0 :::8066 :::* LISTEN 31728/java 
# ./mycat status 
Mycat-server is running (31726). 

# mysql -u tankzhang -p -P 8066 -h 127.0.0.1 //一定要带上127.0.0.1 
Enter password: 
Welcome to the MySQL monitor. Commands end with ; or \g. 
Your MySQL connection id is 1 
Server version: 5.6.29-mycat-1.6-RELEASE-20161028204710 MyCat Server (OpenCloundDB) 

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved. 

Oracle is a registered trademark of Oracle Corporation and/or its 
affiliates. Other names may be trademarks of their respective 
owners. 

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

mysql> show databases; 
+----------+ 
| DATABASE | 
+----------+ 
| mytest | //虚拟数据库 
+----------+ 
1 row in set (0.00 sec) 

mysql> use mytest; 
Reading table information for completion of table and column names 
You can turn off this feature to get a quicker startup with -A 

mysql> CREATE TABLE IF NOT EXISTS `user` ( 
-> `id` int(11) unsigned NOT NULL DEFAULT '0' COMMENT 'ID', 
-> `name` varchar(20) NOT NULL DEFAULT '' COMMENT '姓名', 
-> `create_time` int(10) NOT NULL DEFAULT '0' COMMENT '创建时间', 
-> PRIMARY KEY (`id`) 
-> ) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=1 ; 
Query OK, 0 rows affected (0.08 sec) 
Database changed 
mysql> show tables; 
+----------------+ 
| Tables_in_test | 
+----------------+ 
| user | 
+----------------+ 
1 row in set (0.01 sec) 
mysql> INSERT INTO `user` (`id` ,`name`)VALUES ('1', 'tank'); 
Query OK, 1 row affected (0.00 sec) 

mysql> select * from user; //修改从数据库的user表中的name,会发现读是从从数据库读取的 
+----+-----------+-------------+ 
| id | name | create_time | 
+----+-----------+-------------+ 
| 1 | tankzhang | 0 | 
+----+-----------+-------------+ 
1 row in set (0.01 sec)