ShardingSphere 4.x User Manual-Sharding-JDBC-Manual

Apache ShardingSphere
5 min readSep 7, 2020

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This chapter will introduce the use of Sharding-JDBC. Please refer to Example for more details.

Sharding

Not Use Spring

Introduce Maven Dependency

<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-core</artifactId>
<version>${sharding-sphere.version}</version>
</dependency>

Rule Configuration Based on Java

Sharding database and table of Sharding-JDBC configure descriptions according to rules. The following example is the configuration of two databases plus two tables, whose databases take module and split according to order_id, tables take module and split according to order_id.

// Configure actual data sources
Map<String, DataSource> dataSourceMap = new HashMap<>();

// Configure the first data source
BasicDataSource dataSource1 = new BasicDataSource();
dataSource1.setDriverClassName("com.mysql.jdbc.Driver");
dataSource1.setUrl("jdbc:mysql://localhost:3306/ds0");
dataSource1.setUsername("root");
dataSource1.setPassword("");
dataSourceMap.put("ds0", dataSource1);

// Configure the second data source
BasicDataSource dataSource2 = new BasicDataSource();
dataSource2.setDriverClassName("com.mysql.jdbc.Driver");
dataSource2.setUrl("jdbc:mysql://localhost:3306/ds1");
dataSource2.setUsername("root");
dataSource2.setPassword("");
dataSourceMap.put("ds1", dataSource2);

// Configure Order table rules
TableRuleConfiguration orderTableRuleConfig = new TableRuleConfiguration("t_order","ds${0..1}.t_order${0..1}");

// Configure strategies for database + table sharding
orderTableRuleConfig.setDatabaseShardingStrategyConfig(new InlineShardingStrategyConfiguration("user_id", "ds${user_id % 2}"));
orderTableRuleConfig.setTableShardingStrategyConfig(new InlineShardingStrategyConfiguration("order_id", "t_order${order_id % 2}"));

// Configure sharding rules
ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
shardingRuleConfig.getTableRuleConfigs().add(orderTableRuleConfig);

// Omit order_item table rule configuration
// ...

// Get data source
DataSource dataSource = ShardingDataSourceFactory.createDataSource(dataSourceMap, shardingRuleConfig, new Properties());

Rule Configuration Based on Yaml

Or use Yaml to configure, similar to configurations above:

dataSources:
ds0: !!org.apache.commons.dbcp.BasicDataSource
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/ds0
username: root
password:
ds1: !!org.apache.commons.dbcp.BasicDataSource
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/ds1
username: root
password:
shardingRule:
tables:
t_order:
actualDataNodes: ds${0..1}.t_order${0..1}
databaseStrategy:
inline:
shardingColumn: user_id
algorithmExpression: ds${user_id % 2}
tableStrategy:
inline:
shardingColumn: order_id
algorithmExpression: t_order${order_id % 2}
t_order_item:
actualDataNodes: ds${0..1}.t_order_item${0..1}
databaseStrategy:
inline:
shardingColumn: user_id
algorithmExpression: ds${user_id % 2}
tableStrategy:
inline:
shardingColumn: order_id
algorithmExpression: t_order_item${order_id % 2}
DataSource dataSource = ShardingDataSourceFactory.createDataSource(yamlFile);

Use Native JDBC

Configure objects with ShardingDataSourceFactory or YamlShardingDataSourceFactory to get ShardingDataSource, which is realized by standard JDBC DataSource. Or choose native JDBC to develop through DataSource; or use JPA, MyBatis and other ORM tools. Take native JDBC for example:

DataSource dataSource = ShardingDataSourceFactory.createDataSource(yamlFile);
String sql = "SELECT i.* FROM t_order o JOIN t_order_item i ON o.order_id=i.order_id WHERE o.user_id=? AND o.order_id=?";
try (
Connection conn = dataSource.getConnection();
PreparedStatement preparedStatement = conn.prepareStatement(sql)) {
preparedStatement.setInt(1, 10);
preparedStatement.setInt(2, 1001);
try (ResultSet rs = preparedStatement.executeQuery()) {
while(rs.next()) {
System.out.println(rs.getInt(1));
System.out.println(rs.getInt(2));
}
}
}

Using Spring

Introduce Maven Dependency

<!-- for spring boot -->
<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-spring-boot-starter</artifactId>
<version>${sharding-sphere.version}</version>
</dependency>
<!-- for spring namespace -->
<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-spring-namespace</artifactId>
<version>${sharding-sphere.version}</version>
</dependency>

Rule Configuration Based on Spring Boot

spring.shardingsphere.datasource.names=ds0,ds1spring.shardingsphere.datasource.ds0.type=org.apache.commons.dbcp2.BasicDataSource
spring.shardingsphere.datasource.ds0.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds0.url=jdbc:mysql://localhost:3306/ds0
spring.shardingsphere.datasource.ds0.username=root
spring.shardingsphere.datasource.ds0.password=
spring.shardingsphere.datasource.ds1.type=org.apache.commons.dbcp2.BasicDataSource
spring.shardingsphere.datasource.ds1.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds1.url=jdbc:mysql://localhost:3306/ds1
spring.shardingsphere.datasource.ds1.username=root
spring.shardingsphere.datasource.ds1.password=
spring.shardingsphere.sharding.default-database-strategy.inline.sharding-column=user_id
spring.shardingsphere.sharding.default-database-strategy.inline.algorithm-expression=ds$->{user_id % 2}
spring.shardingsphere.sharding.tables.t_order.actual-data-nodes=ds$->{0..1}.t_order$->{0..1}
spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.sharding-column=order_id
spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.algorithm-expression=t_order$->{order_id % 2}
spring.shardingsphere.sharding.tables.t_order_item.actual-data-nodes=ds$->{0..1}.t_order_item$->{0..1}
spring.shardingsphere.sharding.tables.t_order_item.table-strategy.inline.sharding-column=order_id
spring.shardingsphere.sharding.tables.t_order_item.table-strategy.inline.algorithm-expression=t_order_item$->{order_id % 2}

Rule Configuration Based on Spring Boot + JNDI

If you plan to use Sharding-JDBC in Application Server (such as Tomcat) with Spring boot + JNDI, spring.shardingsphere.datasource.${datasourceName}.jndiName can be used as an alternative to series of configuration of datasource. For example:

spring.shardingsphere.datasource.names=ds0,ds1spring.shardingsphere.datasource.ds0.jndi-name=java:comp/env/jdbc/ds0
spring.shardingsphere.datasource.ds1.jndi-name=jdbc/ds1
spring.shardingsphere.sharding.default-database-strategy.inline.sharding-column=user_id
spring.shardingsphere.sharding.default-database-strategy.inline.algorithm-expression=ds$->{user_id % 2}
spring.shardingsphere.sharding.tables.t_order.actual-data-nodes=ds$->{0..1}.t_order$->{0..1}
spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.sharding-column=order_id
spring.shardingsphere.sharding.tables.t_order.table-strategy.inline.algorithm-expression=t_order$->{order_id % 2}
spring.shardingsphere.sharding.tables.t_order_item.actual-data-nodes=ds$->{0..1}.t_order_item$->{0..1}
spring.shardingsphere.sharding.tables.t_order_item.table-strategy.inline.sharding-column=order_id
spring.shardingsphere.sharding.tables.t_order_item.table-strategy.inline.algorithm-expression=t_order_item$->{order_id % 2}

Rule Configuration Based on Spring Name Space

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:sharding="http://shardingsphere.apache.org/schema/shardingsphere/sharding"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://shardingsphere.apache.org/schema/shardingsphere/sharding
http://shardingsphere.apache.org/schema/shardingsphere/sharding/sharding.xsd
">
<bean id="ds0" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/ds0" />
<property name="username" value="root" />
<property name="password" value="" />
</bean>
<bean id="ds1" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/ds1" />
<property name="username" value="root" />
<property name="password" value="" />
</bean>

<sharding:inline-strategy id="databaseStrategy" sharding-column="user_id" algorithm-expression="ds$->{user_id % 2}" />
<sharding:inline-strategy id="orderTableStrategy" sharding-column="order_id" algorithm-expression="t_order$->{order_id % 2}" />
<sharding:inline-strategy id="orderItemTableStrategy" sharding-column="order_id" algorithm-expression="t_order_item$->{order_id % 2}" />

<sharding:data-source id="shardingDataSource">
<sharding:sharding-rule data-source-names="ds0,ds1">
<sharding:table-rules>
<sharding:table-rule logic-table="t_order" actual-data-nodes="ds$->{0..1}.t_order$->{0..1}" database-strategy-ref="databaseStrategy" table-strategy-ref="orderTableStrategy" />
<sharding:table-rule logic-table="t_order_item" actual-data-nodes="ds$->{0..1}.t_order_item$->{0..1}" database-strategy-ref="databaseStrategy" table-strategy-ref="orderItemTableStrategy" />
</sharding:table-rules>
</sharding:sharding-rule>
</sharding:data-source>
</beans>

Use DataSource in Spring

Inject DataSource to use; or configure DataSource in JPA, Hibernate or MyBatis to use.

@Resource
private DataSource dataSource;

Rule configurations include data source configuration, table rule configuration, database sharding strategy and table sharding strategy. All these are the simplest configuration methods, and the practical use can be more flexible, like multiple sharding keys, table rule configuration bound directly with sharding strategies, etc. For more detailed configurations, please refer to Configuration Manual.

Read-write Split

Not Use Spring

Introduce Maven Dependency

<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-core</artifactId>
<version>${sharding-sphere.version}</version>
</dependency>

Rule Configuration Based on Java

// Configure actual data sources
Map<String, DataSource> dataSourceMap = new HashMap<>();

// Configure master data source
BasicDataSource masterDataSource = new BasicDataSource();
masterDataSource.setDriverClassName("com.mysql.jdbc.Driver");
masterDataSource.setUrl("jdbc:mysql://localhost:3306/ds_master");
masterDataSource.setUsername("root");
masterDataSource.setPassword("");
dataSourceMap.put("ds_master", masterDataSource);

// Configure the first slave data source
BasicDataSource slaveDataSource1 = new BasicDataSource();
slaveDataSource1.setDriverClassName("com.mysql.jdbc.Driver");
slaveDataSource1.setUrl("jdbc:mysql://localhost:3306/ds_slave0");
slaveDataSource1.setUsername("root");
slaveDataSource1.setPassword("");
dataSourceMap.put("ds_slave0", slaveDataSource1);

// Configure the second slave data source
BasicDataSource slaveDataSource2 = new BasicDataSource();
slaveDataSource2.setDriverClassName("com.mysql.jdbc.Driver");
slaveDataSource2.setUrl("jdbc:mysql://localhost:3306/ds_slave1");
slaveDataSource2.setUsername("root");
slaveDataSource2.setPassword("");
dataSourceMap.put("ds_slave1", slaveDataSource2);

// Configure read-write split rule
MasterSlaveRuleConfiguration masterSlaveRuleConfig = new MasterSlaveRuleConfiguration("ds_master_slave", "ds_master", Arrays.asList("ds_slave0", "ds_slave1"));

// Get data source
DataSource dataSource = MasterSlaveDataSourceFactory.createDataSource(dataSourceMap, masterSlaveRuleConfig, new Properties());

Rule Configuration Based on Yaml

Or configure by yaml, similar to the configuration method above:

dataSources:
ds_master: !!org.apache.commons.dbcp.BasicDataSource
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/ds_master
username: root
password:
ds_slave0: !!org.apache.commons.dbcp.BasicDataSource
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/ds_slave0
username: root
password:
ds_slave1: !!org.apache.commons.dbcp.BasicDataSource
driverClassName: com.mysql.jdbc.Driver
url: jdbc:mysql://localhost:3306/ds_slave1
username: root
password:
masterSlaveRule:
name: ds_ms
masterDataSourceName: ds_master
slaveDataSourceNames: [ds_slave0, ds_slave1]

props:
sql.show: true
DataSource dataSource = YamlMasterSlaveDataSourceFactory.createDataSource(yamlFile);

Use Native JDBC

Configure objects with YamlMasterSlaveDataSourceFactory to get MasterSlaveDataSource, which is realized by standard JDBC DataSource interface. Or choose native JDBC to develop through DataSource; or use JPA, MyBatis and other ORM tools. Take native JDBC for example:

DataSource dataSource = YamlMasterSlaveDataSourceFactory.createDataSource(yamlFile);
String sql = "SELECT i.* FROM t_order o JOIN t_order_item i ON o.order_id=i.order_id WHERE o.user_id=? AND o.order_id=?";
try (
Connection conn = dataSource.getConnection();
PreparedStatement preparedStatement = conn.prepareStatement(sql)) {
preparedStatement.setInt(1, 10);
preparedStatement.setInt(2, 1001);
try (ResultSet rs = preparedStatement.executeQuery()) {
while(rs.next()) {
System.out.println(rs.getInt(1));
System.out.println(rs.getInt(2));
}
}
}

Use Spring

Introduce Maven Dependency

<!-- for spring boot -->
<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-spring-boot-starter</artifactId>
<version>${sharding-sphere.version}</version>
</dependency>
<!-- for spring namespace -->
<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-spring-namespace</artifactId>
<version>${sharding-sphere.version}</version>
</dependency>

Rule Configuration Based on Spring Boot

spring.shardingsphere.datasource.names=master,slave0,slave1spring.shardingsphere.datasource.ds-master.type=org.apache.commons.dbcp.BasicDataSource
spring.shardingsphere.datasource.ds-master.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds-master.url=jdbc:mysql://localhost:3306/master
spring.shardingsphere.datasource.ds-master.username=root
spring.shardingsphere.datasource.ds-master.password=
spring.shardingsphere.datasource.ds-slave0.type=org.apache.commons.dbcp.BasicDataSource
spring.shardingsphere.datasource.ds-slave0.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds-slave0.url=jdbc:mysql://localhost:3306/slave0
spring.shardingsphere.datasource.ds-slave0.username=root
spring.shardingsphere.datasource.ds-slave0.password=
spring.shardingsphere.datasource.ds-slave1.type=org.apache.commons.dbcp.BasicDataSource
spring.shardingsphere.datasource.ds-slave1.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds-slave1.url=jdbc:mysql://localhost:3306/slave1
spring.shardingsphere.datasource.ds-slave1.username=root
spring.shardingsphere.datasource.ds-slave1.password=
spring.shardingsphere.masterslave.name=ms
spring.shardingsphere.masterslave.master-data-source-name=master
spring.shardingsphere.masterslave.slave-data-source-names=slave0,slave1
spring.shardingsphere.props.sql.show=true

Rule Configuration Based on Spring Boot + JNDI

If you plan to use Sharding-JDBC in Application Server (such as Tomcat) with Spring boot + JNDI, spring.shardingsphere.datasource.${datasourceName}.jndiName can be used as an alternative to series of configuration of datasource. For example:

spring.shardingsphere.datasource.names=master,slave0,slave1spring.shardingsphere.datasource.master.jndi-name=java:comp/env/jdbc/master
spring.shardingsphere.datasource.slave0.jndi-name=jdbc/slave0
spring.shardingsphere.datasource.slave1.jndi-name=jdbc/slave1
spring.shardingsphere.masterslave.name=ms
spring.shardingsphere.masterslave.master-data-source-name=master
spring.shardingsphere.masterslave.slave-data-source-names=slave0,slave1
spring.shardingsphere.props.sql.show=true

Rule Configuration Based on Spring Name Space

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:master-slave="http://shardingsphere.apache.org/schema/shardingsphere/masterslave"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://shardingsphere.apache.org/schema/shardingsphere/masterslave
http://shardingsphere.apache.org/schema/shardingsphere/masterslave/master-slave.xsd
">
<bean id="ds_master" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/ds_master" />
<property name="username" value="root" />
<property name="password" value="" />
</bean>
<bean id="ds_slave0" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/ds_slave0" />
<property name="username" value="root" />
<property name="password" value="" />
</bean>
<bean id="ds_slave1" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/ds_slave1" />
<property name="username" value="root" />
<property name="password" value="" />
</bean>

<master-slave:data-source id="masterSlaveDataSource" master-data-source-name="ds_master" slave-data-source-names="ds_slave0, ds_slave1" >
<master-slave:props>
<prop key="sql.show">true</prop>
<prop key="executor.size">10</prop>
<prop key="foo">bar</prop>
</master-slave:props>
</master-slave:data-source>
</beans>

Use DataSource in Spring

Inject DataSource to use; or configure DataSource in JPA, Hibernate or MyBatis to use.

@Resource
private DataSource dataSource;

For more detailed configurations, please refer to Configuration Manual.

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