Sharding

Background

The Java API rule configuration for data sharding, which allows users to create ShardingSphereDataSource objects directly by writing Java code, is flexible enough to integrate various types of business systems without relying on additional jar packages.

Parameters

Root Configuration

Class name: org.apache.shardingsphere.sharding.api.config.ShardingRuleConfiguration

Attributes:

Sharding Table Configuration

Class name: org.apache.shardingsphere.sharding.api.config.ShardingTableRuleConfiguration

Attributes:

Sharding Auto Table Configuration

Class name: org.apache.shardingsphere.sharding.api.config.ShardingAutoTableRuleConfiguration

Attributes:

Sharding Strategy Configuration

Standard Sharding Strategy Configuration

Class name: org.apache.shardingsphere.sharding.api.config.strategy.sharding.StandardShardingStrategyConfiguration

Attributes:

Complex Sharding Strategy Configuration

Class name: org.apache.shardingsphere.sharding.api.config.strategy.sharding.ComplexShardingStrategyConfiguration

Attributes:

Hint Sharding Strategy Configuration

Class name: org.apache.shardingsphere.sharding.api.config.strategy.sharding.HintShardingStrategyConfiguration

Attributes:

None Sharding Strategy Configuration

Class name: org.apache.shardingsphere.sharding.api.config.strategy.sharding.NoneShardingStrategyConfiguration

Attributes: None

Please refer to Built-in Sharding Algorithm List for more details about type of algorithm.

Distributed Key Strategy Configuration

Class name: org.apache.shardingsphere.sharding.api.config.strategy.keygen.KeyGenerateStrategyConfiguration

Attributes:

Please refer to Built-in Key Generate Algorithm List for more details about type of algorithm.

Sharding audit Strategy Configuration

Class name：org.apache.shardingsphere.sharding.api.config.strategy.audit.ShardingAuditStrategyConfiguration

Attributes：

Please refer to Built-in Sharding Audit Algorithm List for more details about type of algorithm.

Procedure

1. Create an authentic data source mapping relationship, with key as the logical name of the data source and value as the DataSource object.
2. Create the sharding rule object ShardingRuleConfiguration, and initialize the sharding table objects—ShardingTableRuleConfiguration, the set of bound tables, the set of broadcast tables, and parameters like library sharding strategy and the database sharding strategy, on which the data sharding depends.
3. Using the ShardingSphereDataSource method of calling the ShardingSphereDataSourceFactory subject to create the ShardingSphereDataSource.

Sample

public final class ShardingDatabasesAndTablesConfigurationPrecise implements ExampleConfiguration {
    @Override
    public DataSource getDataSource() throws SQLException {
        return ShardingSphereDataSourceFactory.createDataSource(createDataSourceMap(), Collections.singleton(createShardingRuleConfiguration()), new Properties());
    }
    private ShardingRuleConfiguration createShardingRuleConfiguration() {
        ShardingRuleConfiguration result = new ShardingRuleConfiguration();
        result.getTables().add(getOrderTableRuleConfiguration());
        result.getTables().add(getOrderItemTableRuleConfiguration());
        result.getBindingTableGroups().add(new ShardingTableReferenceRuleConfiguration("foo", "t_order, t_order_item"));
        result.getBroadcastTables().add("t_address");
        result.setDefaultDatabaseShardingStrategy(new StandardShardingStrategyConfiguration("user_id", "inline"));
        result.setDefaultTableShardingStrategy(new StandardShardingStrategyConfiguration("order_id", "standard_test_tbl"));
        Properties props = new Properties();
        props.setProperty("algorithm-expression", "demo_ds_${user_id % 2}");
        result.getShardingAlgorithms().put("inline", new AlgorithmConfiguration("INLINE", props));
        result.getShardingAlgorithms().put("standard_test_tbl", new AlgorithmConfiguration("STANDARD_TEST_TBL", new Properties()));
        result.getKeyGenerators().put("snowflake", new AlgorithmConfiguration("SNOWFLAKE", new Properties()));
        result.getAuditors().put("sharding_key_required_auditor", new AlgorithmConfiguration("DML_SHARDING_CONDITIONS", new Properties()));
        return result;
    }
    private ShardingTableRuleConfiguration getOrderTableRuleConfiguration() {
        ShardingTableRuleConfiguration result = new ShardingTableRuleConfiguration("t_order", "demo_ds_${0..1}.t_order_${[0, 1]}");
        result.setKeyGenerateStrategy(new KeyGenerateStrategyConfiguration("order_id", "snowflake"));
        result.setAuditStrategy(new ShardingAuditStrategyConfiguration(Collections.singleton("sharding_key_required_auditor"), true));
        return result;
    }
    private ShardingTableRuleConfiguration getOrderItemTableRuleConfiguration() {
        ShardingTableRuleConfiguration result = new ShardingTableRuleConfiguration("t_order_item", "demo_ds_${0..1}.t_order_item_${[0, 1]}");
        result.setKeyGenerateStrategy(new KeyGenerateStrategyConfiguration("order_item_id", "snowflake"));
        return result;
    }
    private Map<String, DataSource> createDataSourceMap() {
        Map<String, DataSource> result = new HashMap<>();
        result.put("demo_ds_0", DataSourceUtil.createDataSource("demo_ds_0"));
        result.put("demo_ds_1", DataSourceUtil.createDataSource("demo_ds_1"));
        return result;
    }
}

Related References

• Core Feature: Data Sharding
• Developer Guide: Data Sharding