影子库

背景信息

如果您只想使用 Java API 方式配置使用 ShardingSphere 影子库功能请参考以下配置。

参数解释

配置入口

类名称：org.apache.shardingsphere.shadow.api.config.ShadowRuleConfiguration

可配置属性：

影子数据源配置

类名称：org.apache.shardingsphere.shadow.api.config.datasource.ShadowDataSourceConfiguration

可配置属性：

影子表配置

类名称：org.apache.shardingsphere.shadow.api.config.table.ShadowTableConfiguration

可配置属性：

影子算法配置

类名称：org.apache.shardingsphere.infra.config.algorithm.AlgorithmConfiguration

可配置属性：

算法类型的详情，请参见内置影子算法列表。

操作步骤

1. 创建生产和影子数据源。
2. 配置影子规则

• 配置影子数据源
• 配置影子表
• 配置影子算法

配置示例

public final class ShadowConfiguration {
    @Override
    public DataSource getDataSource() throws SQLException {
        Map<String, DataSource> dataSourceMap = createDataSourceMap();
        return ShardingSphereDataSourceFactory.createDataSource(dataSourceMap, createRuleConfigurations(), createShardingSphereProps());
    }
    private Map<String, DataSource> createDataSourceMap() {
        Map<String, DataSource> result = new LinkedHashMap<>();
        result.put("ds", DataSourceUtil.createDataSource("demo_ds"));
        result.put("ds_shadow", DataSourceUtil.createDataSource("shadow_demo_ds"));
        return result;
    }
    private Collection<RuleConfiguration> createRuleConfigurations() {
        Collection<RuleConfiguration> result = new LinkedList<>();
        ShadowRuleConfiguration shadowRule = new ShadowRuleConfiguration();
        shadowRule.setDataSources(createShadowDataSources());
        shadowRule.setTables(createShadowTables());
        shadowRule.setShadowAlgorithms(createShadowAlgorithmConfigurations());
        result.add(shadowRule);
        return result;
    }
    private Map<String, ShadowDataSourceConfiguration> createShadowDataSources() {
        Map<String, ShadowDataSourceConfiguration> result = new LinkedHashMap<>();
        result.put("shadow-data-source", new ShadowDataSourceConfiguration("ds", "ds_shadow"));
        return result;
    }
    private Map<String, ShadowTableConfiguration> createShadowTables() {
        Map<String, ShadowTableConfiguration> result = new LinkedHashMap<>();
        result.put("t_user", new ShadowTableConfiguration(Collections.singletonList("shadow-data-source"), createShadowAlgorithmNames()));
        return result;
    }
    private Collection<String> createShadowAlgorithmNames() {
        Collection<String> result = new LinkedList<>();
        result.add("user-id-insert-match-algorithm");
        result.add("simple-hint-algorithm");
        return result;
    }
    private Map<String, AlgorithmConfiguration> createShadowAlgorithmConfigurations() {
        Map<String, AlgorithmConfiguration> result = new LinkedHashMap<>();
        Properties userIdInsertProps = new Properties();
        userIdInsertProps.setProperty("operation", "insert");
        userIdInsertProps.setProperty("column", "user_type");
        userIdInsertProps.setProperty("value", "1");
        result.put("user-id-insert-match-algorithm", new AlgorithmConfiguration("VALUE_MATCH", userIdInsertProps));
        return result;
    }
}

相关参考

影子库的特性描述