Mycat作为独立的数据库中间件,我们只需要进行相关的配置,就可以非常方便的帮我们实现水平切分、垂直切分、读写分离等功能,但Mysql的主从复制需要我们通过其它方式实现。这里假设我们已经搭建好相关的环境,下面就开始我们的实践吧!
<user name="mysqlmycat">
<property name="password">mysqlmycat</property>
<property name="schemas">mysqlmycats</property>
</user>
<schema name="mysqlmycats" checkSQLschema="false" sqlMaxLimit="100">
<table name="tb_user" dataNode="mydn1,mydn2" rule="user-mod-long" />
<table name="tb_student" dataNode="mydn1,mydn2" rule="student-mod-long" />
</schema>
<dataNode name="mydn1" dataHost="myhost1" database="master1mycat" />
<dataNode name="mydn2" dataHost="myhost2" database="master2mycat" />
<dataHost name="myhost1" maxCon="100" minCon="10" balance="3" writeType="0" dbType="mysql" dbDriver="native">
<heartbeat>select user()</heartbeat>
<writeHost host="hostM1" url="localhost:3306" user="root" password="xxx">
<readHost host="hostS1" url="localhost:3307" user="root" password="xxx"/>
</writeHost>
</dataHost>
<dataHost name="myhost2" maxCon="100" minCon="10" balance="3" writeType="0" dbType="mysql" dbDriver="native">
<heartbeat>select user()</heartbeat>
<writeHost host="hostM2" url="localhost:3308" user="root" password="xxx" >
<readHost host="hostS2" url="localhost:3309" user="root" password="xxx"/>
</writeHost>
</dataHost>
<tableRule name="user-mod-long">
<rule>
<columns>id</columns>
<algorithm>mod-long</algorithm>
</rule>
</tableRule>
<tableRule name="student-mod-long">
<rule>
<columns>user_id</columns>
<algorithm>mod-long</algorithm>
</rule>
</tableRule>
<function name="mod-long" class="io.mycat.route.function.PartitionByMod">
<property name="count">2</property>
</function>
修改了配置文件后,别忘了重启Mycat,如果有异常出现,请通过查看logs目录下的日志文件进行排查。
spring:
jpa:
show-sql: true
hibernate:
ddl-auto: update
naming:
strategy: org.hibernate.cfg.ImprovedNamingStrategy
properties:
hibernate:
dialect: org.hibernate.dialect.MySQL5Dialect
datasource:
url: jdbc:mysql://localhost:8066/mysqlmycats?characterEncoding=UTF-8&useSSL=false&autoReconnect=true&rewriteBatchedStatements=true
username: mysqlmycat
password: mysqlmycat
@Entity
@Table(name = "tb_user")
@Data
public class User {
@Id
private Long id;
private String name;
private Integer gender;
}
@Entity
@Table(name = "tb_student")
@Data
public class Student {
@Id
private Long id;
private String name;
@Column(unique = true)
private Long userId;
}
public interface UserDao extends JpaRepository<User, Long> {
Page<User> findByNameLike(String name, Pageable pageable);
}
public interface StudentDao extends JpaRepository<Student, Long> {
Page<User> findByNameLike(String name, Pageable pageable);
}
@Test
public void testAdd() {
for (long i = 0; i < 30; i++) {
User user = new User();
user.setId(i);
user.setName("张三" + i);
user.setGender(i % 2 == 0 ? 0 : 1);
userDao.save(user);
Student student = new Student();
student.setId(System.currentTimeMillis() + i);
student.setName("张三学生" + i);
student.setUserId(i);
studentDao.save(student);
}
}
测试结果:数据按id取模的方式划分到了两个数据库中,同时从库同步了主库的数据
水平切分(id取模)
@Test
public void testFind() {
Pageable pageable = new PageRequest(0, 10, Sort.Direction.DESC, "id");
List<User> userList = userDao.findByNameLike("%张三2%", pageable).getContent();
userList.forEach(System.out::println);
Pageable pageable2 = new PageRequest(0, 10, Sort.Direction.DESC, "userId");
List<Student> studentList = studentDao.findByNameLike("%张三学生1%", pageable2).getContent();
studentList.forEach(System.out::println);
}
测试结果:按照模糊匹配及id降序的方式输出结果
测试模糊查询+分页
测试结果:读操作都走了从库
读写分离,读都走了从库
Mycat官网 Mycat从零开始 Mycat权威指南 GitHub:Mycat-Server Wiki:Mycat-Server Issues:Mycat-Server mysql中间件研究(Atlas,Cobar,TDDL) mysql中间件研究(Atlas,Cobar,TDDL,Mycat,Heisenberg,Oceanus,Vitess,OneProxy)