分库分表实战可运行demo
为什么要分库分表
关系型数据库以MySQL为例，单机的存储能力、连接数是有限的，它自身就很容易会成为系统的瓶颈。当单表数据量在百万以内时，我们还可以通过 添加从库、优化索引提升性能 。
一旦数据量朝着 千万以上趋势增长 ，再怎么优化数据库，很多操作性能仍下降严重。为了减少数据库的负担，提升数据库响应速度，缩短查询时间，这时候就需要进行分库分表 。如何分库分表
分库分表就是要将 大量数据分散到多个数据库 中，使每个数据库中数据量小响应速度快 ，以此来提升数据库整体性能 。
针对数据切分类型，大致可以分为： 垂直（纵向）切分和水平（横向）切分 两种。以下是分库分表的demopackage com.lyz.sharding.algorithm; import java.util.Collection; import java.util.LinkedHashSet; import com.dangdang.ddframe.rdb.sharding.api.ShardingValue; import com.dangdang.ddframe.rdb.sharding.api.strategy.database.SingleKeyDatabaseShardingAlgorithm; import com.google.common.collect.Range; /** * user表分库的逻辑函数 * @author liuyazhuang * */ public class StudentSingleKeyDatabaseShardingAlgorithm implements SingleKeyDatabaseShardingAlgorithm{ /** * sql 中关键字 匹配符为 =的时候，表的路由函数 */ public String doEqualSharding(Collection availableTargetNames, ShardingValue shardingValue) { for (String each : availableTargetNames) { if (each.endsWith(shardingValue.getValue() % 2 + ＂＂)) { return each; } } throw new IllegalArgumentException(); } /** * sql 中关键字 匹配符为 in 的时候，表的路由函数 */ public Collection doInSharding(Collection availableTargetNames, ShardingValue shardingValue) { Collection result = new LinkedHashSet(availableTargetNames.size()); for (Integer value : shardingValue.getValues()) { for (String tableName : availableTargetNames) { if (tableName.endsWith(value % 2 + ＂＂)) { result.add(tableName); } } } return result; } /** * sql 中关键字 匹配符为 between的时候，表的路由函数 */ public Collection doBetweenSharding(Collection availableTargetNames, ShardingValue shardingValue) { Collection result = new LinkedHashSet(availableTargetNames.size()); Range range = (Range) shardingValue.getValueRange(); for (Integer i = range.lowerEndpoint(); i <= range.upperEndpoint(); i++) { for (String each : availableTargetNames) { if (each.endsWith(i % 2 + ＂＂)) { result.add(each); } } } return result; } } ``` ``` package com.lyz.sharding.algorithm; import java.util.Collection; import java.util.LinkedHashSet; import com.dangdang.ddframe.rdb.sharding.api.ShardingValue; import com.dangdang.ddframe.rdb.sharding.api.strategy.table.SingleKeyTableShardingAlgorithm; import com.google.common.collect.Range; /** * 因为t_student实际表在每个库中只有2个，所以 %2 * @author iuyazhuang * */ public class StudentSingleKeyTableShardingAlgorithm implements SingleKeyTableShardingAlgorithm{ /** * sql 中 = 操作时，table的映射 */ public String doEqualSharding(Collection tableNames, ShardingValue shardingValue) { for (String each : tableNames) { if (each.endsWith(＂0＂.concat(String.valueOf(shardingValue.getValue() % 2)))) { return each; } } throw new IllegalArgumentException(); } /** * sql 中 in 操作时，table的映射 */ public Collection doInSharding(Collection tableNames, ShardingValue shardingValue) { Collection result = new LinkedHashSet(tableNames.size()); for (Integer value : shardingValue.getValues()) { for (String tableName : tableNames) { if (tableName.endsWith(＂0＂.concat(String.valueOf(value % 2)))) { result.add(tableName); } } } return result; } /** * sql 中 between 操作时，table的映射 */ public Collection doBetweenSharding(Collection tableNames, ShardingValue shardingValue) { Collection result = new LinkedHashSet(tableNames.size()); Range range = (Range) shardingValue.getValueRange(); for (Integer i = range.lowerEndpoint(); i <= range.upperEndpoint(); i++) { for (String each : tableNames) { if (each.endsWith(＂0＂.concat(String.valueOf(i % 2)))) { result.add(each); } } } return result; } } ``` ``` package com.lyz.sharding.algorithm; import java.util.Collection; import java.util.LinkedHashSet; import com.dangdang.ddframe.rdb.sharding.api.ShardingValue; import com.dangdang.ddframe.rdb.sharding.api.strategy.database.SingleKeyDatabaseShardingAlgorithm; import com.google.common.collect.Range; /** * user表分库的逻辑函数 * @author liuyazhuang * */ public class UserSingleKeyDatabaseShardingAlgorithm implements SingleKeyDatabaseShardingAlgorithm{ /** * sql 中关键字 匹配符为 =的时候，表的路由函数 */ public String doEqualSharding(Collection availableTargetNames, ShardingValue shardingValue) { for (String each : availableTargetNames) { if (each.endsWith(shardingValue.getValue() % 2 + ＂＂)) { return each; } } throw new IllegalArgumentException(); } /** * sql 中关键字 匹配符为 in 的时候，表的路由函数 */ public Collection doInSharding(Collection availableTargetNames, ShardingValue shardingValue) { Collection result = new LinkedHashSet(availableTargetNames.size()); for (Integer value : shardingValue.getValues()) { for (String tableName : availableTargetNames) { if (tableName.endsWith(value % 2 + ＂＂)) { result.add(tableName); } } } return result; } /** * sql 中关键字 匹配符为 between的时候，表的路由函数 */ public Collection doBetweenSharding(Collection availableTargetNames, ShardingValue shardingValue) { Collection result = new LinkedHashSet(availableTargetNames.size()); Range range = (Range) shardingValue.getValueRange(); for (Integer i = range.lowerEndpoint(); i <= range.upperEndpoint(); i++) { for (String each : availableTargetNames) { if (each.endsWith(i % 2 + ＂＂)) { result.add(each); } } } return result; } } ``` ``` package com.lyz.sharding.algorithm; import java.util.Collection; import java.util.LinkedHashSet; import com.dangdang.ddframe.rdb.sharding.api.ShardingValue; import com.dangdang.ddframe.rdb.sharding.api.strategy.table.SingleKeyTableShardingAlgorithm; import com.google.common.collect.Range; /** * 因为t_student实际表在每个库中只有3个，所以 %3 * @author iuyazhuang * */ public class UserSingleKeyTableShardingAlgorithm implements SingleKeyTableShardingAlgorithm{ /** * sql 中 = 操作时，table的映射 */ public String doEqualSharding(Collection tableNames, ShardingValue shardingValue) { for (String each : tableNames) { if (each.endsWith((＂0＂.concat(String.valueOf(shardingValue.getValue() % 3))))) { return each; } } throw new IllegalArgumentException(); } /** * sql 中 in 操作时，table的映射 */ public Collection doInSharding(Collection tableNames, ShardingValue shardingValue) { Collection result = new LinkedHashSet(tableNames.size()); for (Integer value : shardingValue.getValues()) { for (String tableName : tableNames) { if (tableName.endsWith((＂0＂.concat(String.valueOf(value % 3))))) { result.add(tableName); } } } return result; } /** * sql 中 between 操作时，table的映射 */ public Collection doBetweenSharding(Collection tableNames, ShardingValue shardingValue) { Collection result = new LinkedHashSet(tableNames.size()); Range range = (Range) shardingValue.getValueRange(); for (Integer i = range.lowerEndpoint(); i <= range.upperEndpoint(); i++) { for (String each : tableNames) { if (each.endsWith((＂0＂.concat(String.valueOf(i % 3))))) { result.add(each); } } } return result; } } ``` ``` package com.lyz.sharding.entity; import java.io.Serializable; /** * 学生类 * @author liuyazhuang * */ public class Student implements Serializable { private static final long serialVersionUID = 8920597824668331209L; private Integer id; private Integer studentId; private String name; private Integer age; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getStudentId() { return studentId; } public void setStudentId(Integer studentId) { this.studentId = studentId; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } @Override public String toString() { return ＂Student [id=＂ + id + ＂, studentId=＂ + studentId + ＂, name=＂ + name + ＂, age=＂ + age + ＂]＂; } } ``` ``` package com.lyz.sharding.entity; import java.io.Serializable; /** * 用户类 * @author liuyazhuang * */ public class User implements Serializable { private static final long serialVersionUID = 1L; private Integer id; private Integer userId; private String name; private Integer age; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public Integer getUserId() { return userId; } public void setUserId(Integer userId) { this.userId = userId; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } @Override public String toString() { return ＂User [id=＂ + id + ＂, userId=＂ + userId + ＂, name=＂ + name + ＂, age=＂ + age + ＂]＂; } } ``` ``` package com.lyz.sharding.mapper; import java.util.List; import com.lyz.sharding.entity.Student; /** * 处理学生的数据操作接口 * @author liuyazhuang * */ public interface StudentMapper { Integer insert(Student s); List findAll(); List findByStudentIds(List studentIds); } ``` ``` package com.lyz.sharding.mapper; import java.util.List; import com.lyz.sharding.entity.User; /** * 处理用户的数据操作接口 * @author liuyazhuang * */ public interface UserMapper { Integer insert(User u); List findAll(); List findByUserIds(List userIds); } ``` ``` package com.lyz.sharding.service.impl; import javax.annotation.Resource; import org.springframework.stereotype.Service; import com.lyz.sharding.entity.Student; import com.lyz.sharding.mapper.StudentMapper; import com.lyz.sharding.service.StudentService; @Service public class StudentServiceImpl implements StudentService{ @Resource public StudentMapper studentMapper; public boolean insert(Student student) { return studentMapper.insert(student) > 0 ? true : false; } } ``` ``` package com.lyz.sharding.service.impl; import java.util.List; import javax.annotation.Resource; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Propagation; import org.springframework.transaction.annotation.Transactional; import com.lyz.sharding.entity.Student; import com.lyz.sharding.entity.User; import com.lyz.sharding.mapper.StudentMapper; import com.lyz.sharding.mapper.UserMapper; import com.lyz.sharding.service.UserService; @Service @Transactional public class UserServiceImpl implements UserService { @Resource public UserMapper userMapper; @Resource public StudentMapper studentMapper; public boolean insert(User u) { return userMapper.insert(u) > 0 ? true :false; } public List findAll() { return userMapper.findAll(); } public List findByUserIds(List ids) { return userMapper.findByUserIds(ids); } @Transactional(propagation=Propagation.REQUIRED) public void transactionTestSucess() { User u = new User(); u.setUserId(13); u.setAge(25); u.setName(＂war3 1.27＂); userMapper.insert(u); Student student = new Student(); student.setStudentId(21); student.setAge(21); student.setName(＂hehe＂); studentMapper.insert(student); } @Transactional(propagation=Propagation.REQUIRED) public void transactionTestFailure() throws IllegalAccessException { User u = new User(); u.setUserId(13); u.setAge(25); u.setName(＂war3 1.27 good＂); userMapper.insert(u); Student student = new Student(); student.setStudentId(21); student.setAge(21); student.setName(＂hehe1＂); studentMapper.insert(student); throw new IllegalAccessException(); } } ``` ``` package com.lyz.sharding.service; import com.lyz.sharding.entity.Student; /** * 处理学生的service * @author liuyazhuang * */ public interface StudentService { boolean insert(Student student); } ``` ``` package com.lyz.sharding.service; import java.util.List; import com.lyz.sharding.entity.User; /** * 处理用户的Service * @author liuyazhuang * */ public interface UserService { public boolean insert(User u); public List findAll(); public List findByUserIds(List ids); public void transactionTestSucess(); public void transactionTestFailure() throws IllegalAccessException; } ``` ``` <?xml version=＂1.0＂ encoding=＂UTF-8＂ ?> insert into t_student (student_id,name,age) values (#{studentId},#{name},#{age}) id,student_id,name,age ``` ``` <?xml version=＂1.0＂ encoding=＂UTF-8＂ ?> insert into t_user (user_id,name,age) values (#{userId},#{name},#{age}) id,user_id,name,age ``` ``` jdbc_driver0 = com.mysql.jdbc.Driver jdbc_url0 = jdbc:mysql://localhost:3306/sharding_0 jdbc_username0 = root jdbc_password0 = root jdbc_driver1 = com.mysql.jdbc.Driver jdbc_url1 = jdbc:mysql://localhost:3306/sharding_1 jdbc_username1 = root jdbc_password1 = root validationQuery=SELECT 1 ``` ``` <?xml version=＂1.0＂ encoding=＂UTF-8＂?> classpath:config/resource/jdbc_dev.properties
``` ``` <?xml version=＂1.0＂ encoding=＂UTF-8＂?> t_user_00 t_user_01 t_user_02
t_student_00 t_student_01
[ ][ ]
``` ``` package com.lyz.sharding.test; import java.util.Arrays; import java.util.List; import javax.annotation.Resource; import org.junit.Assert; import org.junit.Test; import org.junit.runner.RunWith; import org.springframework.test.context.ContextConfiguration; import org.springframework.test.context.junit4.SpringJUnit4ClassRunner; import com.lyz.sharding.entity.Student; import com.lyz.sharding.entity.User; import com.lyz.sharding.service.StudentService; import com.lyz.sharding.service.UserService; /** * 测试分库分表规则 * @author liuyazhuang * */ @RunWith(SpringJUnit4ClassRunner.class) @ContextConfiguration(locations = { ＂classpath*:config/spring/spring-database.xml＂, ＂classpath*:config/spring/spring-sharding.xml＂ }) public class ShardingJdbcMybatisTest { @Resource public UserService userService; @Resource public StudentService studentService; @Test public void testUserInsert() { User u = new User(); u.setUserId(11); u.setAge(25); u.setName(＂github＂); Assert.assertEquals(userService.insert(u), true); } @Test public void testStudentInsert() { Student student = new Student(); student.setStudentId(21); student.setAge(21); student.setName(＂hehe＂); Assert.assertEquals(studentService.insert(student), true); } @Test public void testFindAll(){ List users = userService.findAll(); if(null != users && !users.isEmpty()){ for(User u :users){ System.out.println(u); } } } @Test public void testSQLIN(){ List users = userService.findByUserIds(Arrays.asList(1)); if(null != users && !users.isEmpty()){ for(User u :users){ System.out.println(u); } } } @Test public void testTransactionTestSucess(){ userService.transactionTestSucess(); } @Test(expected = IllegalAccessException.class) public void testTransactionTestFailure() throws IllegalAccessException{ userService.transactionTestFailure(); } }
以上代码在本地是可以运行的，需要配置好环境，连上数据库。
