Configuration of the sample
Data fragmentation
The following configuration realization of DataSourceUtil DataSourceUtil, ModuloShardingTableAlgorithm user-defined implementation class, ModuloShardingTableAlgorithm detailed examples
DataSource getShardingDataSource(a) throws SQLException {
ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
shardingRuleConfig.getTableRuleConfigs().add(getOrderTableRuleConfiguration());
shardingRuleConfig.getTableRuleConfigs().add(getOrderItemTableRuleConfiguration());
shardingRuleConfig.getBindingTableGroups().add("t_order, t_order_item");
shardingRuleConfig.getBroadcastTables().add("t_config");
shardingRuleConfig.setDefaultDatabaseShardingStrategyConfig(new InlineShardingStrategyConfiguration("user_id"."ds${user_id % 2}"));
shardingRuleConfig.setDefaultTableShardingStrategyConfig(new StandardShardingStrategyConfiguration("order_id".new ModuloShardingTableAlgorithm()));
return ShardingDataSourceFactory.createDataSource(createDataSourceMap(), shardingRuleConfig, new Properties());
}
private static KeyGeneratorConfiguration getKeyGeneratorConfiguration(a) {
KeyGeneratorConfiguration result = new KeyGeneratorConfiguration("SNOWFLAKE"."order_id");
return result;
}
TableRuleConfiguration getOrderTableRuleConfiguration(a) {
TableRuleConfiguration result = new TableRuleConfiguration("t_order"."ds${0.. 1}.t_order${0.. 1}");
result.setKeyGeneratorConfig(getKeyGeneratorConfiguration());
return result;
}
TableRuleConfiguration getOrderItemTableRuleConfiguration(a) {
TableRuleConfiguration result = new TableRuleConfiguration("t_order_item"."ds${0.. 1}.t_order_item${0.. 1}");
return result;
}
Map<String, DataSource> createDataSourceMap(a) {
Map<String, DataSource> result = new HashMap<>();
result.put("ds0", DataSourceUtil.createDataSource("ds0"));
result.put("ds1", DataSourceUtil.createDataSource("ds1"));
return result;
}
Copy the codeReading and writing separation
DataSource getMasterSlaveDataSource(a) throws SQLException {
MasterSlaveRuleConfiguration masterSlaveRuleConfig = new MasterSlaveRuleConfiguration("ds_master_slave"."ds_master", Arrays.asList("ds_slave0"."ds_slave1"));
return MasterSlaveDataSourceFactory.createDataSource(createDataSourceMap(), masterSlaveRuleConfig, new Properties());
}
Map<String, DataSource> createDataSourceMap(a) {
Map<String, DataSource> result = new HashMap<>();
result.put("ds_master", DataSourceUtil.createDataSource("ds_master"));
result.put("ds_slave0", DataSourceUtil.createDataSource("ds_slave0"));
result.put("ds_slave1", DataSourceUtil.createDataSource("ds_slave1"));
return result;
}
Copy the codeData desensitization
DataSource getEncryptDataSource(a) throws SQLException {
return EncryptDataSourceFactory.createDataSource(DataSourceUtil.createDataSource("demo_ds"), getEncryptRuleConfiguration(), new Properties());
}
private static EncryptRuleConfiguration getEncryptRuleConfiguration(a) {
Properties props = new Properties();
props.setProperty("aes.key.value"."123456");
EncryptorRuleConfiguration encryptorConfig = new EncryptorRuleConfiguration("AES", props);
EncryptColumnRuleConfiguration columnConfig = new EncryptColumnRuleConfiguration("plain_pwd"."cipher_pwd".""."aes");
EncryptTableRuleConfiguration tableConfig = new EncryptTableRuleConfiguration(Collections.singletonMap("pwd", columnConfig));
EncryptRuleConfiguration encryptRuleConfig = new EncryptRuleConfiguration();
encryptRuleConfig.getEncryptors().put("aes", encryptorConfig);
encryptRuleConfig.getTables().put("t_encrypt", tableConfig);
return encryptRuleConfig;
}
Copy the codeData fragmentation + Read/write separation
DataSource getDataSource(a) throws SQLException {
ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
shardingRuleConfig.getTableRuleConfigs().add(getOrderTableRuleConfiguration());
shardingRuleConfig.getTableRuleConfigs().add(getOrderItemTableRuleConfiguration());
shardingRuleConfig.getBindingTableGroups().add("t_order, t_order_item");
shardingRuleConfig.getBroadcastTables().add("t_config");
shardingRuleConfig.setDefaultDatabaseShardingStrategyConfig(new StandardShardingStrategyConfiguration("user_id".new PreciseModuloShardingDatabaseAlgorithm()));
shardingRuleConfig.setDefaultTableShardingStrategyConfig(new StandardShardingStrategyConfiguration("order_id".new PreciseModuloShardingTableAlgorithm()));
shardingRuleConfig.setMasterSlaveRuleConfigs(getMasterSlaveRuleConfigurations());
return ShardingDataSourceFactory.createDataSource(createDataSourceMap(), shardingRuleConfig, new Properties());
}
private static KeyGeneratorConfiguration getKeyGeneratorConfiguration(a) {
KeyGeneratorConfiguration result = new KeyGeneratorConfiguration("SNOWFLAKE"."order_id");
return result;
}
TableRuleConfiguration getOrderTableRuleConfiguration(a) {
TableRuleConfiguration result = new TableRuleConfiguration("t_order"."ds_${0.. 1}.t_order_${[0, 1]}");
result.setKeyGeneratorConfig(getKeyGeneratorConfiguration());
return result;
}
TableRuleConfiguration getOrderItemTableRuleConfiguration(a) {
TableRuleConfiguration result = new TableRuleConfiguration("t_order_item"."ds_${0.. 1}.t_order_item_${[0, 1]}");
return result;
}
List<MasterSlaveRuleConfiguration> getMasterSlaveRuleConfigurations(a) {
MasterSlaveRuleConfiguration masterSlaveRuleConfig1 = new MasterSlaveRuleConfiguration("ds_0"."demo_ds_master_0", Arrays.asList("demo_ds_master_0_slave_0"."demo_ds_master_0_slave_1"));
MasterSlaveRuleConfiguration masterSlaveRuleConfig2 = new MasterSlaveRuleConfiguration("ds_1"."demo_ds_master_1", Arrays.asList("demo_ds_master_1_slave_0"."demo_ds_master_1_slave_1"));
return Lists.newArrayList(masterSlaveRuleConfig1, masterSlaveRuleConfig2);
}
Map<String, DataSource> createDataSourceMap(a) {
final Map<String, DataSource> result = new HashMap<>();
result.put("demo_ds_master_0", DataSourceUtil.createDataSource("demo_ds_master_0"));
result.put("demo_ds_master_0_slave_0", DataSourceUtil.createDataSource("demo_ds_master_0_slave_0"));
result.put("demo_ds_master_0_slave_1", DataSourceUtil.createDataSource("demo_ds_master_0_slave_1"));
result.put("demo_ds_master_1", DataSourceUtil.createDataSource("demo_ds_master_1"));
result.put("demo_ds_master_1_slave_0", DataSourceUtil.createDataSource("demo_ds_master_1_slave_0"));
result.put("demo_ds_master_1_slave_1", DataSourceUtil.createDataSource("demo_ds_master_1_slave_1"));
return result;
}
Copy the codeData fragmentation + data desensitization
public DataSource getDataSource(a) throws SQLException {
ShardingRuleConfiguration shardingRuleConfig = new ShardingRuleConfiguration();
shardingRuleConfig.getTableRuleConfigs().add(getOrderTableRuleConfiguration());
shardingRuleConfig.getTableRuleConfigs().add(getOrderItemTableRuleConfiguration());
shardingRuleConfig.getTableRuleConfigs().add(getOrderEncryptTableRuleConfiguration());
shardingRuleConfig.getBindingTableGroups().add("t_order, t_order_item");
shardingRuleConfig.setDefaultDatabaseShardingStrategyConfig(new InlineShardingStrategyConfiguration("user_id"."demo_ds_${user_id % 2}"));
shardingRuleConfig.setDefaultTableShardingStrategyConfig(new StandardShardingStrategyConfiguration("order_id".new PreciseModuloShardingTableAlgorithm()));
shardingRuleConfig.setEncryptRuleConfig(getEncryptRuleConfiguration());
return ShardingDataSourceFactory.createDataSource(createDataSourceMap(), shardingRuleConfig, new Properties());
}
private static TableRuleConfiguration getOrderTableRuleConfiguration(a) {
TableRuleConfiguration result = new TableRuleConfiguration("t_order"."demo_ds_${0.. 1}.t_order_${[0, 1]}");
result.setKeyGeneratorConfig(getKeyGeneratorConfiguration());
return result;
}
private static TableRuleConfiguration getOrderItemTableRuleConfiguration(a) {
TableRuleConfiguration result = new TableRuleConfiguration("t_order_item"."demo_ds_${0.. 1}.t_order_item_${[0, 1]}");
result.setEncryptorConfig(new EncryptorConfiguration("MD5"."status".new Properties()));
return result;
}
private static EncryptRuleConfiguration getEncryptRuleConfiguration(a) {
Properties props = new Properties();
props.setProperty("aes.key.value"."123456");
EncryptorRuleConfiguration encryptorConfig = new EncryptorRuleConfiguration("AES", props);
EncryptColumnRuleConfiguration columnConfig = new EncryptColumnRuleConfiguration("plain_order"."cipher_order".""."aes");
EncryptTableRuleConfiguration tableConfig = new EncryptTableRuleConfiguration(Collections.singletonMap("order_id", columnConfig));
EncryptRuleConfiguration encryptRuleConfig = new EncryptRuleConfiguration();
encryptRuleConfig.getEncryptors().put("aes", encryptorConfig);
encryptRuleConfig.getTables().put("t_order", tableConfig);
return encryptRuleConfig;
}
private static Map<String, DataSource> createDataSourceMap(a) {
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;
}
private static KeyGeneratorConfiguration getKeyGeneratorConfiguration(a) {
return new KeyGeneratorConfiguration("SNOWFLAKE"."order_id".new Properties());
}
Copy the codegovernance
DataSource getDataSource(a) throws SQLException {
/ / OrchestrationShardingDataSourceFactory can replace OrchestrationMasterSlaveDataSourceFactory or OrchestrationEncryptDataSourceFactory
return OrchestrationShardingDataSourceFactory.createDataSource(
createDataSourceMap(), createShardingRuleConfig(), new HashMap<String, Object>(), new Properties(),
new OrchestrationConfiguration(createCenterConfigurationMap()));
}
private Map<String, CenterConfiguration> createCenterConfigurationMap(a) {
Map<String, CenterConfiguration> instanceConfigurationMap = new HashMap<String, CenterConfiguration>();
CenterConfiguration config = createCenterConfiguration();
instanceConfigurationMap.put("orchestration-sharding-data-source", config);
return instanceConfigurationMap;
}
private CenterConfiguration createCenterConfiguration(a) {
Properties properties = new Properties();
properties.setProperty("overwrite", overwrite);
CenterConfiguration result = new CenterConfiguration("zookeeper", properties);
result.setServerLists("localhost:2181");
result.setNamespace("sharding-sphere-orchestration");
result.setOrchestrationType("registry_center,config_center");
return result;
}
Copy the codeConfiguration Item Description
Data fragmentation
ShardingDataSourceFactory
Data source creation factory for data sharding.
| The name of the | The data type | instructions |
|---|---|---|
| dataSourceMap | Map<String, DataSource> | Data Source Configuration |
| shardingRuleConfig | ShardingRuleConfiguration | Rules for configuring data fragments |
| props (?) | Properties | The configuration properties |
ShardingRuleConfiguration
Fragment rule configuration object.
| The name of the | The data type | instructions |
|---|---|---|
| tableRuleConfigs | Collection<TableRuleConfiguration> | Sharding rule list |
| bindingTableGroups (?) | Collection<String> | List of binding table rules |
| broadcastTables (?) | Collection<String> | List of broadcast table rules |
| defaultDataSourceName (?) | String | Tables without sharding rules are located through the default data source |
| defaultDatabaseShardingStrategyConfig (?) | ShardingStrategyConfiguration | Default repository splitting policy |
| defaultTableShardingStrategyConfig (?) | ShardingStrategyConfiguration | Default split table policy |
| defaultKeyGeneratorConfig (?) | KeyGeneratorConfiguration | The default on the column value generator configuration, the default will use org. Apache. Shardingsphere. Core. The keygen. The generator. The impl. SnowflakeKeyGenerator |
| masterSlaveRuleConfigs (?) | Collection<MasterSlaveRuleConfiguration> | Read/write separation rule. By default, read/write separation is not used |
TableRuleConfiguration
Table sharding rule configuration object.
| The name of the | The data type | instructions |
|---|---|---|
| logicTable | String | Logical table name |
| actualDataNodes (?) | String | Consists of data source name + table name, separated by decimal points. Multiple tables are comma-separated and support inline expressions. By default, data nodes are generated using known data sources and logical table names for broadcast tables (that is, each library needs the same table for associated query, mostly dictionary tables) or only separate databases without separate tables and all libraries have identical table structures |
| databaseShardingStrategyConfig (?) | ShardingStrategyConfiguration | Branch library policy. By default, the default branch library policy is used |
| tableShardingStrategyConfig (?) | ShardingStrategyConfiguration | Sub-table policy. By default, the default sub-table policy is used |
| keyGeneratorConfig (?) | KeyGeneratorConfiguration | Auto-increment column value generator configuration, which defaults to using the default auto-increment primary key generator |
| encryptorConfiguration (?) | EncryptorConfiguration | Encryption and decryption generator configuration |
StandardShardingStrategyConfiguration
ShardingStrategyConfiguration implementation class for standard fragmentation of the single shard key scenes.
| The name of the | The data type | instructions |
|---|---|---|
| shardingColumn | String | Shard column name |
| preciseShardingAlgorithm | PreciseShardingAlgorithm | Exact sharding algorithm for = and IN |
| rangeShardingAlgorithm (?) | RangeShardingAlgorithm | Range sharding algorithm for BETWEEN |
ComplexShardingStrategyConfiguration
ShardingStrategyConfiguration implementation class for more shard key composite subdivision scenarios.
| The name of the | The data type | instructions |
|---|---|---|
| shardingColumns | String | Shard column name. Multiple columns are separated by commas |
| shardingAlgorithm | ComplexKeysShardingAlgorithm | Compound sharding algorithm |
InlineShardingStrategyConfiguration
ShardingStrategyConfiguration implementation class, used to configure line expression subdivision strategy.
| The name of the | The data type | instructions |
|---|---|---|
| shardingColumn | String | Shard column name |
| algorithmExpression | String | The line expression of the sharding algorithm must comply with groovy syntax. For details, seeLine expression |
HintShardingStrategyConfiguration
ShardingStrategyConfiguration implementation class, used to configure Hint way subdivision strategy.
| The name of the | The data type | instructions |
|---|---|---|
| shardingAlgorithm | HintShardingAlgorithm | Hint sharding algorithm |
NoneShardingStrategyConfiguration
ShardingStrategyConfiguration implementation class, used to configure shard strategy.
KeyGeneratorConfiguration
| The name of the | The data type | instructions |
|---|---|---|
| column | String | Increment column name |
| type | String | Increment column value generator type, you can customize or choose the built-in type: SNOWFLAKE/UUID |
| props | Properties | Configuration of properties associated with the increment column value generator |
Properties
Property configuration item that can be a property of the following auto-increment column value generator.
SNOWFLAKE
| The name of the | The data type | instructions |
|---|---|---|
| worker.id (?) | long | Unique ID of the working machine. Default is 0 |
| max.tolerate.time.difference.milliseconds (?) | long | Maximum time allowed for a clock rollback, in milliseconds. The default is 10 milliseconds |
| max.vibration.offset (?) | int | The value ranges from 0 to 4096. The default value is 1. If the value generated by this algorithm is used as the fragment value, you are advised to configure this attribute. The result is always 0 or 1 after the key generated by this algorithm is modular 2^n (2^n is generally the number of branches or tables) in different milliseconds |
EncryptRuleConfiguration
| The name of the | The data type | instructions |
|---|---|---|
| encryptors | Map<String, EncryptorRuleConfiguration> | Configuration list of encryption and decryption device. You can customize or select the built-in type: MD5/AES |
| tables | Map<String, EncryptTableRuleConfiguration> | Encryption table configuration list |
EncryptorRuleConfiguration
| The name of the | The data type | instructions |
|---|---|---|
| type | String | The encryption and decryption type can be customized or the built-in type is MD5 or AES |
| properties | Properties | Note: To use AES encryption, configure the KEY attribute aes.key.value for the AES encryption |
EncryptTableRuleConfiguration
| The name of the | The data type | instructions |
|---|---|---|
| tables | Map<String, EncryptColumnRuleConfiguration> | Encrypted column configuration list |
EncryptColumnRuleConfiguration
| The name of the | The data type | instructions |
|---|---|---|
| plainColumn | String | Store plaintext fields |
| cipherColumn | String | Field that stores ciphertext |
| assistedQueryColumn | String | Auxiliary query field, in view of ShardingQueryAssistedEncryptor types of encryption device for auxiliary query |
| encryptor | String | The name of the decryptor |
Properties
Properties Configuration item, which can be the following properties.
| The name of the | The data type | instructions |
|---|---|---|
| sql.show (?) | boolean | Whether to enable SQL display. Default value: false |
| executor.size (?) | int | Number of worker threads. Default value: number of CPU cores |
| max.connections.size.per.query (?) | int | The maximum number of connections per physical database allocated for each query. Default value: 1 |
| check.table.metadata.enabled (?) | boolean | Whether to check sub-table metadata consistency at startup. Default value: false |
| query.with.cipher.column (?) | boolean | Specifies whether to use ciphertext when plaintext columns exist. Default value: true |
| allow.range.query.with.inline.sharding (?) | boolean | Whether to allow a range query when using the inline table policy. Default: false |
Reading and writing separation
MasterSlaveDataSourceFactory
Create factories for read-write data sources.
| The name of the | The data type | instructions |
|---|---|---|
| dataSourceMap | Map<String, DataSource> | Mapping of data sources to their names |
| masterSlaveRuleConfig | MasterSlaveRuleConfiguration | Read/write separation rule |
| props (?) | Properties | The configuration properties |
MasterSlaveRuleConfiguration
Read/write separation rule configuration object.
| The name of the | The data type | instructions |
|---|---|---|
| name | String | Read/write split data source name |
| masterDataSourceName | String | Primary library data source name |
| slaveDataSourceNames | Collection<String> | List of slave data source names |
| loadBalanceAlgorithm (?) | MasterSlaveLoadBalanceAlgorithm | Load balancing algorithm from library |
Properties
Properties Configuration item, which can be the following properties.
| The name of the | The data type | instructions |
|---|---|---|
| sql.show (?) | boolean | Whether to print SQL parsing and rewriting logs. Default value: false |
| executor.size (?) | int | The number of worker threads used for SQL execution. Zero indicates unlimited. Default value: 0 |
| max.connections.size.per.query (?) | int | The maximum number of connections per physical database allocated for each query. Default value: 1 |
| check.table.metadata.enabled (?) | boolean | Whether to check sub-table metadata consistency at startup. Default value: false |
Data desensitization
EncryptDataSourceFactory
| The name of the | The data type | instructions |
|---|---|---|
| dataSource | DataSource | Data source, any connection pool |
| encryptRuleConfig | EncryptRuleConfiguration | Data desensitization rules |
| props (?) | Properties | The configuration properties |
EncryptRuleConfiguration
| The name of the | The data type | instructions |
|---|---|---|
| encryptors | Map<String, EncryptorRuleConfiguration> | Configuration list of encryption and decryption device. You can customize or select the built-in type: MD5/AES |
| tables | Map<String, EncryptTableRuleConfiguration> | Encryption table configuration list |
Properties
Properties Configuration item, which can be the following properties.
| The name of the | The data type | instructions |
|---|---|---|
| sql.show (?) | boolean | Whether to enable SQL display. Default value: false |
| query.with.cipher.column (?) | boolean | Specifies whether to use ciphertext when plaintext columns exist. Default value: true |
governance
OrchestrationShardingDataSourceFactory
Data sharding + data source factory for governance.
| The name of the | The data type | instructions |
|---|---|---|
| dataSourceMap | Map<String, DataSource> | With ShardingDataSourceFactory |
| shardingRuleConfig | ShardingRuleConfiguration | With ShardingDataSourceFactory |
| props (?) | Properties | With ShardingDataSourceFactory |
| orchestrationConfig | OrchestrationConfiguration | Governance Rule Configuration |
OrchestrationMasterSlaveDataSourceFactory
Read/write separation + governed data source factory.
| The name of the | The data type | instructions |
|---|---|---|
| dataSourceMap | Map<String, DataSource> | With MasterSlaveDataSourceFactory |
| masterSlaveRuleConfig | MasterSlaveRuleConfiguration | With MasterSlaveDataSourceFactory |
| props (?) | Properties | With ShardingDataSourceFactory |
| orchestrationConfig | OrchestrationConfiguration | Governance Rule Configuration |
OrchestrationEncryptDataSourceFactory
Data desensitization + data source factory governance.
| The name of the | The data type | instructions |
|---|---|---|
| dataSource | DataSource | With EncryptDataSourceFactory |
| encryptRuleConfig | EncryptRuleConfiguration | With EncryptDataSourceFactory |
| props (?) | Properties | With ShardingDataSourceFactory |
| orchestrationConfig | OrchestrationConfiguration | Governance Rule Configuration |
OrchestrationConfiguration
Governance rule configuration objects.
| The name of the | The data type | instructions |
|---|---|---|
| instanceConfigurationMap | Map<String, CenterConfiguration> | Configure the configuration map of the configuration center and registry, where key is the name and value is the configuration or registry |
CenterConfiguration
Used to configure the configuration center or registry.
| The name of the | The data type | instructions |
|---|---|---|
| type | String | Configure the instance type of the center or registry, such as ZooKeeper or ETCD, Apollo, NACOS |
| properties | String | Configure other parameters required by this example, such as connection parameters of ZooKeeper. For details, see Properties configuration |
| orchestrationType | String | Configure the type of the center or registry, such as config-center or registry-center. If both, “setOrchestrationType(“registry_center,config_center”);” |
| serverLists | String | A list of connections to a configuration center or registry server, including IP addresses and port numbers, separated by commas. Such as: host1:2181, host2:2181 |
| namespace (?) | String | Configure the namespace of the center or registry |
The general configuration of properties is as follows:
| The name of the | The data type | instructions |
|---|---|---|
| overwrite | boolean | Whether the local configuration overrides the registry configuration, and if so, the local configuration prevails at each startup |
If ZooKeeper is used as the configuration center or/and registry, properties can also be configured:
| The name of the | The data type | instructions |
|---|---|---|
| digest (?) | String | Access token to connect to the registry. By default, no permission authentication is required |
| operationTimeoutMilliseconds (?) | int | The number of milliseconds that the operation timed out. Default: 500 milliseconds |
| maxRetries (?) | int | Maximum number of retries after a connection failure. The default value is 3 |
| retryIntervalMilliseconds (?) | int | Number of milliseconds between retries. Default: 500 milliseconds |
| timeToLiveSeconds (?) | int | The number of seconds that temporary nodes live. The default is 60 seconds |
If etCD is used as the configuration center or/and registry, properties can also be configured:
| The name of the | The data type | instructions |
|---|---|---|
| timeToLiveSeconds (?) | long | TTL Indicates the TTL, in seconds. The default value is 30 seconds |
If Apollo is used as the configuration center, properties can also be configured with:
| The name of the | The data type | instructions |
|---|---|---|
| appId (?) | String | Apollo appId, default is “APOLLO_SHARDINGSPHERE” |
| env (?) | String | Apollo env, default is “DEV” |
| clusterName (?) | String | Apollo clusterName, default is “default” |
| administrator (?) | String | Apollo Administrator, default is “” |
| token (?) | String | Apollo Token, default value “” |
| portalUrl (?) | String | Apollo portalUrl, default is “” |
| connectTimeout (?) | int | Apollo connectTimeout. The default value is 1000 milliseconds |
| readTimeout (?) | int | Apollo readTimeout, default is 5000 ms |
If nacOS is used as the configuration center, properties can also be configured with:
| The name of the | The data type | instructions |
|---|---|---|
| group (?) | String | Nacos group configuration, default is “SHARDING_SPHERE_DEFAULT_GROUP” |
| timeout (?) | long | Nacos Specifies the timeout period for obtaining data, in milliseconds. The default value is 3000 milliseconds |