HA

Background

Build high availability rule configuration through Java API.

Parameters

Root Configuration

Class name: org.apache.shardingsphere.dbdiscovery.api.config.DatabaseDiscoveryRuleConfiguration Attributes:

Name	Data Type	Description
dataSources (+)	Collection<DatabaseDiscoveryDataSourceRuleConfiguration>	Data source configuration
discoveryHeartbeats (+)	Map<String, DatabaseDiscoveryHeartBeatConfiguration>	Detect heartbeat configuration
discoveryTypes (+)	Map<String, AlgorithmConfiguration>	Database discovery type configuration

Data Source Configuration

Class name: org.apache.shardingsphere.dbdiscovery.api.config.rule.DatabaseDiscoveryDataSourceRuleConfiguration

Attributes:

Name	Data Type	Description
groupName (+)	String	Database discovery group name
dataSourceNames (+)	Collection<String>	Data source names, multiple data source names separated with comma. Such as: ds_0, ds_1
discoveryHeartbeatName (+)	String	Detect heartbeat name
discoveryTypeName (+)	String	Database discovery type name

Detect Heartbeat Configuration

Class name: org.apache.shardingsphere.dbdiscovery.api.config.rule.DatabaseDiscoveryHeartBeatConfiguration

Attributes:

Name	Data Type	Description
props (+)	Properties	Detect heartbeat attribute configuration, keep-alive-cron configuration, cron expression. Such as: `0/5 * * * * ?`

Database Discovery Type Configuration

Class name: org.apache.shardingsphere.infra.config.algorithm.AlgorithmConfiguration

Attributes：

Name	Data Type	Description
type (+)	String	Database discovery type, such as: MySQL.MGR
props (?)	Properties	Required parameters for high-availability types, such as MGR’s group-name

Procedure

Import Maven dependency.

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

Notice: Please change ${latest.release.version} to the actual version.

Sample


// Build data source ds_0, ds_1, ds_2
Map<String, DataSource> dataSourceMap = new HashMap<>(3, 1);
dataSourceMap.put("ds_0", createDataSource1("primary_demo_ds"));
dataSourceMap.put("ds_1", createDataSource2("primary_demo_ds"));
dataSourceMap.put("ds_2", createDataSource3("primary_demo_ds"));

DataSource dataSource = ShardingSphereDataSourceFactory.createDataSource("database_discovery_db", dataSourceMap, Arrays.asList(createDatabaseDiscoveryConfiguration(), createReadwriteSplittingConfiguration()), null);

private static DatabaseDiscoveryRuleConfiguration createDatabaseDiscoveryConfiguration() {
    DatabaseDiscoveryDataSourceRuleConfiguration dataSourceRuleConfiguration = new DatabaseDiscoveryDataSourceRuleConfiguration("readwrite_ds", Arrays.asList("ds_0, ds_1, ds_2"), "mgr-heartbeat", "mgr");
    return new DatabaseDiscoveryRuleConfiguration(Collections.singleton(dataSourceRuleConfiguration), createDiscoveryHeartbeats(), createDiscoveryTypes());
}

private static ReadwriteSplittingRuleConfiguration createReadwriteSplittingConfiguration() {
    ReadwriteSplittingDataSourceRuleConfiguration dataSourceConfiguration1 = new ReadwriteSplittingDataSourceRuleConfiguration("replica_ds", new DynamicReadwriteSplittingStrategyConfiguration("readwrite_ds", true), "");
    return new ReadwriteSplittingRuleConfiguration(Arrays.asList(dataSourceConfiguration1), Collections.emptyMap());
}

private static Map<String, AlgorithmConfiguration> createDiscoveryTypes() {
    Map<String, AlgorithmConfiguration> discoveryTypes = new HashMap<>(1， 1);
    Properties props = new Properties();
    props.put("group-name", "558edd3c-02ec-11ea-9bb3-080027e39bd2");
    discoveryTypes.put("mgr", new AlgorithmConfiguration("MGR", props));
    return discoveryTypes;
}

private static Map<String, DatabaseDiscoveryHeartBeatConfiguration> createDiscoveryHeartbeats() {
    Map<String, DatabaseDiscoveryHeartBeatConfiguration> discoveryHeartBeatConfiguration = new HashMap<>(1， 1);
    Properties props = new Properties();
    props.put("keep-alive-cron", "0/5 * * * * ?");
    discoveryHeartBeatConfiguration.put("mgr-heartbeat", new DatabaseDiscoveryHeartBeatConfiguration(props));
    return discoveryHeartBeatConfiguration;
}

HA