Sharding-Jdbc實現mysql分庫分表
簡單介紹
數據庫分庫分表和讀寫分離區別,分庫分表是在多個庫建相同的表和同一個庫建不同的表,根據隨機或者哈希等方式查找實現。讀寫分離是爲了解決數據庫的讀寫性能不足,使用主庫master進行寫操作,從庫slave進行讀操作,通過binglog實現主被庫數據的同步。
實現數據庫分庫分表可以自己實現,也可以使用mycat和sharding-jdbc實現。
插播概念
(1)olap和oltp聯機事務處理OLTP(on-line transaction processing)、聯機分析處理OLAP(On-Line Analytical Processing)。OLTP是傳統的關係型數據庫的主要應用,主要是基本的、日常的事務處理,例如銀行交易。OLAP是數據倉庫系統的主要應用,支持複雜的分析操作,側重決策支持,並且提供直觀易懂的查詢結果。
(2)分佈式數據庫的自增ID不是自增的。分佈式數據庫分頁查詢需要使用插入時間實現。
(3)explain命令,explain顯示了mysql如何使用索引來處理select語句以及連接表。可以幫助選擇更好的索引和寫出更優化的查詢語句。在select語句前面加上就可以。
Sharding-Jdbc介紹
sharding-jdbc是噹噹網開源的一款客戶端代理中間價。sharding-jdbc包含分庫分片和讀寫分離功能。對應用的代碼沒有侵入型,幾乎沒有任何改動,兼容主流orm框架,主流數據庫連接池。目前屬於apache的孵化項目shardingSphere,發展迅猛。sharding-jdbc實現實現讀寫分離不能實現主從庫數據同步
Sharding-Jdbc使用(Spring boot)
(1)創建sharding-jdbc項目和數據庫 ds_master_0,ds_master_1,ds_master_0_slave_0,ds_master_1_slave_0
create table order0
(
id bigint(11) not null comment '主鍵ID' primary key,
user_id bigint(11) null comment '用戶ID',
order_id bigint(11) null comment '訂單ID'
);
create table order1
(
id bigint(11) not null comment '主鍵ID' primary key,
user_id bigint(11) null comment '用戶ID',
order_id bigint(11) null comment '訂單ID'
);
(2)添加依賴
<dependency>
<groupId>io.shardingsphere</groupId>
<artifactId>sharding-jdbc-spring-boot-starter</artifactId>
<version>3.0.0</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.13</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.0</version>
</dependency>
(3)配置文件
spring.application.name=sharding-jdbc
#mybatis
mybatis.configuration.map-underscore-to-camel-case=true
mybatis.mapper-locations=classpath:mapper/*Mapper.xml
#當註冊遇到相同名字是否允許被註冊,在配置中心無效
spring.main.allow-bean-definition-overriding=true
#所有主從庫
sharding.jdbc.datasource.names=dsmaster0,dsmaster1,dsmaster0slave0,dsmaster1slave0
#dsmaster0
sharding.jdbc.datasource.dsmaster0.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.dsmaster0.driver-class-name=com.mysql.cj.jdbc.Driver
sharding.jdbc.datasource.dsmaster0.url=jdbc:mysql://ailijie.top:3306/ds_master_0?useSSL=false
sharding.jdbc.datasource.dsmaster0.username=root
sharding.jdbc.datasource.dsmaster0.password=
#slave for ds_master_0
sharding.jdbc.datasource.dsmaster0slave0.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.dsmaster0slave0.driver-class-name=com.mysql.cj.jdbc.Driver
sharding.jdbc.datasource.dsmaster0slave0.url=jdbc:mysql://ailijie.top:3306/ds_master_0_slave_0?useSSL=false
sharding.jdbc.datasource.dsmaster0slave0.username=root
sharding.jdbc.datasource.dsmaster0slave0.password=
#dsmaster1
sharding.jdbc.datasource.dsmaster1.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.dsmaster1.driver-class-name=com.mysql.cj.jdbc.Driver
sharding.jdbc.datasource.dsmaster1.url=jdbc:mysql://ailijie.top:3306/ds_master_1?useSSL=false
sharding.jdbc.datasource.dsmaster1.username=root
sharding.jdbc.datasource.dsmaster1.password=
#slave for ds_master_1
sharding.jdbc.datasource.dsmaster1slave0.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.dsmaster1slave0.driver-class-name=com.mysql.cj.jdbc.Driver
sharding.jdbc.datasource.dsmaster1slave0.url=jdbc:mysql://ailijie.top:3306/ds_master_1_slave_0?useSSL=false
sharding.jdbc.datasource.dsmaster1slave0.username=root
sharding.jdbc.datasource.dsmaster1slave0.password=
#分庫規則
sharding.jdbc.config.sharding.default-database-strategy.inline.sharding-column=user_id
sharding.jdbc.config.sharding.default-database-strategy.inline.algorithm-expression=dsmaster${user_id % 2}
#分表規則
sharding.jdbc.config.sharding.tables.order.actual-data-nodes=dsmaster${0..1}.order${0..1}
sharding.jdbc.config.sharding.tables.order.table-strategy.inline.shardingColumn=order_id
sharding.jdbc.config.sharding.tables.order.table-strategy.inline.algorithmExpression=order${order_id % 2}
#使用id作爲分佈式主鍵
sharding.jdbc.config.sharding.tables.order.key-generator-column-name=user_id
#邏輯主從庫名和實際主從庫映射關係
#sharding.jdbc.config.sharding.master-slave-rules.ds0.master-data-source-name=dsmaster0
#用逗號分隔
#sharding.jdbc.config.sharding.master-slave-rules.ds0.slave-data-source-names=dsmaster0
#sharding.jdbc.config.sharding.master-slave-rules.dsmaster1.masterDataSourceName=dsmaster1
#sharding.jdbc.config.sharding.master-slave-rules.dsmaster1.slaveDataSourceNames=dsmaster1slave0
(5)實體類 Order
@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class Order implements Serializable {
private static final long serialVersionUID = 427226138907372838L;
private Long id;
private Integer userId;
private Integer orderId;
}
(4)controller外部接口
@Slf4j
@RequestMapping("sharding")
@RestController
public class ShardingController {
@Autowired
private OrderMapper orderMapper;
@RequestMapping
public String helloShardin(){
return "hello Sharding-jdbc";
}
@RequestMapping("insert")
public void insert(@RequestParam Integer orderId, @RequestParam Integer userId) {
Order order = Order.builder()
.orderId(orderId).userId(userId).build();
orderMapper.insert(order);
Long id = order.getId();
log.info("Generated Key--id:" + id);
}
@RequestMapping("queryAll")
public void findAll() {
List<Order> orders = orderMapper.queryAll();
log.info("user:{}", orders);
log.info("user:{}",orders.size());
}
@RequestMapping("getById")
public void getById(@RequestParam Long id) {
Order order = orderMapper.queryById(id);
log.info("user:{}", order);
}
@RequestMapping("getByUserId")
public void getByUserId(@RequestParam Long userId) {
List<Order> orders = orderMapper.queryByUserId(userId);
log.info("user:{}", orders);
}
@RequestMapping("deleteById")
public void deleteById(@RequestParam Long id) {
orderMapper.deleteById(id);
log.info("user:{}", id);
}
}
使用sharding-jdbc沒有侵入性,不會影響業務代碼。
可以使用Springboot的配置文件規範進行配置。
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