数据分片

语法说明

Sharding Table Rule

CREATE SHARDING TABLE RULE shardingTableRuleDefinition [, shardingTableRuleDefinition] ...

ALTER SHARDING TABLE RULE shardingTableRuleDefinition [, shardingTableRuleDefinition] ...

DROP SHARDING TABLE RULE tableName [, tableName] ...

CREATE DEFAULT SHARDING shardingScope STRATEGY (shardingStrategy)

ALTER DEFAULT SHARDING shardingScope STRATEGY (shardingStrategy)

DROP DEFAULT SHARDING shardingScope STRATEGY;

CREATE SHARDING ALGORITHM shardingAlgorithmDefinition [, shardingAlgorithmDefinition] ...

ALTER SHARDING ALGORITHM shardingAlgorithmDefinition [, shardingAlgorithmDefinition] ...

DROP SHARDING ALGORITHM algorithmName [, algorithmName] ...

CREATE SHARDING KEY GENERATOR keyGeneratorDefinition [, keyGeneratorDefinition] ...

ALTER SHARDING KEY GENERATOR keyGeneratorDefinition [, keyGeneratorDefinition] ...

DROP SHARDING KEY GENERATOR keyGeneratorName [, keyGeneratorName] ...

shardingTableRuleDefinition:
    shardingAutoTableRule | shardingTableRule

shardingAutoTableRule:
    tableName(resources, shardingColumn, algorithmDefinition [, keyGenerateDeclaration])

shardingTableRule:
    tableName(dataNodes [, databaseStrategy] [, tableStrategy] [, keyGenerateDeclaration])

resources:
    RESOURCES(resource [, resource] ...)

dataNodes:
    DATANODES(dataNode [, dataNode] ...)

resource:
    resourceName | inlineExpression

dataNode:
    resourceName | inlineExpression

shardingColumn:
    SHARDING_COLUMN=columnName

algorithmDefinition:
    TYPE(NAME=shardingAlgorithmType [, PROPERTIES([algorithmProperties])])

keyGenerateDeclaration:
    keyGenerateDefinition | keyGenerateConstruction

keyGenerateDefinition:
    KEY_GENERATE_STRATEGY(COLUMN=columnName, strategyDefinition)

shardingScope:
    DATABASE | TABLE

databaseStrategy:
    DATABASE_STRATEGY(shardingStrategy)

tableStrategy:
    TABLE_STRATEGY(shardingStrategy)

keyGenerateConstruction
    KEY_GENERATE_STRATEGY(COLUMN=columnName, KEY_GENERATOR=keyGenerateAlgorithmName)

shardingStrategy:
    TYPE=strategyType, shardingColumn, shardingAlgorithm

shardingAlgorithm:
    existingAlgorithm | autoCreativeAlgorithm

existingAlgorithm:
    SHARDING_ALGORITHM=shardingAlgorithmName

autoCreativeAlgorithm:
    SHARDING_ALGORITHM(algorithmDefinition)

strategyDefinition:
    TYPE(NAME=keyGenerateStrategyType [, PROPERTIES([algorithmProperties])])

shardingAlgorithmDefinition:
    shardingAlgorithmName(algorithmDefinition)

algorithmProperties:
    algorithmProperty [, algorithmProperty] ...

algorithmProperty:
    key=value   

keyGeneratorDefinition: 
    keyGeneratorName (algorithmDefinition)
  • RESOURCES 需使用 RDL 管理的数据源资源；
  • shardingAlgorithmType 指定自动分片算法类型，请参考 自动分片算法；
  • keyGenerateStrategyType 指定分布式主键生成策略，请参考 分布式主键；
  • 重复的 tableName 将无法被创建；
  • shardingAlgorithm 能够被不同的 Sharding Table Rule 复用，因此在执行 DROP SHARDING TABLE RULE 时，对应的 shardingAlgorithm 不会被移除；
  • 如需移除 shardingAlgorithm，请执行 DROP SHARDING ALGORITHM；
  • strategyType 指定分片策略，请参考分片策略；
  • Sharding Table Rule 同时支持 Auto Table 和 Table 两种类型，两者在语法上有所差异，对应配置文件请参考 数据分片 ；
  • 使用 autoCreativeAlgorithm 方式指定 shardingStrategy 时，将会自动创建新的分片算法，算法命名规则为 tableName_strategyType_shardingAlgorithmType，如 t_order_database_inline。

Sharding Binding Table Rule

CREATE SHARDING BINDING TABLE RULES bindTableRulesDefinition [, bindTableRulesDefinition] ...

ALTER SHARDING BINDING TABLE RULES bindTableRulesDefinition [, bindTableRulesDefinition] ...

DROP SHARDING BINDING TABLE RULES bindTableRulesDefinition [, bindTableRulesDefinition] ...

bindTableRulesDefinition:
    (tableName [, tableName] ... )
  • ALTER 会使用新的配置直接覆盖数据库内的绑定表配置

Sharding Broadcast Table Rule

CREATE SHARDING BROADCAST TABLE RULES (tableName [, tableName] ...)

ALTER SHARDING BROADCAST TABLE RULES (tableName [, tableName] ...)

DROP SHARDING BROADCAST TABLE RULES (tableName [, tableName] ...)
  • ALTER 会使用新的配置直接覆盖数据库内的广播表配置

Sharding Scaling Rule

CREATE SHARDING SCALING RULE scalingName [scalingRuleDefinition]

DROP SHARDING SCALING RULE scalingName

ENABLE SHARDING SCALING RULE scalingName

DISABLE SHARDING SCALING RULE scalingName

scalingRuleDefinition:
    [inputDefinition] [, outputDefinition] [, streamChannel] [, completionDetector] [, dataConsistencyChecker]

inputDefinition:
    INPUT ([workerThread] [, batchSize] [, rateLimiter])

outputDefinition:
    OUTPUT ([workerThread] [, batchSize] [, rateLimiter])

completionDetector:
    COMPLETION_DETECTOR (algorithmDefinition)

dataConsistencyChecker:
    DATA_CONSISTENCY_CHECKER (algorithmDefinition)

rateLimiter:
    RATE_LIMITER (algorithmDefinition)

streamChannel:
    STREAM_CHANNEL (algorithmDefinition)

workerThread:
    WORKER_THREAD=intValue

batchSize:
    BATCH_SIZE=intValue

intValue:
    INT
  • ENABLE 用于设置启用哪个弹性伸缩配置；
  • DISABLE 将禁用当前正在使用的配置；
  • 创建 schema 中第一个弹性伸缩配置时，默认启用。

示例

Sharding Table Rule

Key Generator

CREATE SHARDING KEY GENERATOR snowflake_key_generator (
TYPE(NAME=SNOWFLAKE)
);

ALTER SHARDING KEY GENERATOR snowflake_key_generator (
TYPE(NAME=SNOWFLAKE)
);

DROP SHARDING KEY GENERATOR snowflake_key_generator;

Auto Table

CREATE SHARDING TABLE RULE t_order (
RESOURCES(resource_0,resource_1),
SHARDING_COLUMN=order_id,TYPE(NAME=hash_mod,PROPERTIES("sharding-count"=4)),
KEY_GENERATE_STRATEGY(COLUMN=another_id,TYPE(NAME=snowflake))
);

ALTER SHARDING TABLE RULE t_order (
RESOURCES(resource_0,resource_1,resource_2,resource_3),
SHARDING_COLUMN=order_id,TYPE(NAME=hash_mod,PROPERTIES("sharding-count"=16)),
KEY_GENERATE_STRATEGY(COLUMN=another_id,TYPE(NAME=snowflake))
);

DROP SHARDING TABLE RULE t_order;

DROP SHARDING ALGORITHM t_order_hash_mod;

Table

CREATE SHARDING ALGORITHM table_inline (
TYPE(NAME=inline,PROPERTIES("algorithm-expression"="t_order_item_${order_id % 2}"))
);

CREATE SHARDING TABLE RULE t_order_item (
DATANODES("resource_${0..1}.t_order_item_${0..1}"),
DATABASE_STRATEGY(TYPE=standard,SHARDING_COLUMN=user_id,SHARDING_ALGORITHM(TYPE(NAME=inline,PROPERTIES("algorithm-expression"="resource_${user_id % 2}")))),
TABLE_STRATEGY(TYPE=standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=table_inline),
KEY_GENERATE_STRATEGY(COLUMN=another_id,KEY_GENERATOR=snowflake_key_generator)
);

ALTER SHARDING ALGORITHM database_inline (
TYPE(NAME=inline,PROPERTIES("algorithm-expression"="resource_${user_id % 4}"))
),table_inline (
TYPE(NAME=inline,PROPERTIES("algorithm-expression"="t_order_item_${order_id % 4}"))
);

ALTER SHARDING TABLE RULE t_order_item (
DATANODES("resource_${0..3}.t_order_item${0..3}"),
DATABASE_STRATEGY(TYPE=standard,SHARDING_COLUMN=user_id,SHARDING_ALGORITHM=database_inline),
TABLE_STRATEGY(TYPE=standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=table_inline),
KEY_GENERATE_STRATEGY(COLUMN=another_id,KEY_GENERATOR=snowflake_key_generator)
);

DROP SHARDING TABLE RULE t_order_item;

DROP SHARDING ALGORITHM database_inline;

CREATE DEFAULT SHARDING DATABASE STRATEGY (
TYPE = standard,SHARDING_COLUMN=order_id,SHARDING_ALGORITHM=database_inline
);

ALTER DEFAULT SHARDING DATABASE STRATEGY (
TYPE = standard,SHARDING_COLUMN=another_id,SHARDING_ALGORITHM=database_inline
);

DROP DEFAULT SHARDING DATABASE STRATEGY;

Sharding Binding Table Rule

CREATE SHARDING BINDING TABLE RULES (t_order,t_order_item),(t_1,t_2);

ALTER SHARDING BINDING TABLE RULES (t_order,t_order_item);

DROP SHARDING BINDING TABLE RULES;

DROP SHARDING BINDING TABLE RULES (t_order,t_order_item);

Sharding Broadcast Table Rule

CREATE SHARDING BROADCAST TABLE RULES (t_b,t_a);

ALTER SHARDING BROADCAST TABLE RULES (t_b,t_a,t_3);

DROP SHARDING BROADCAST TABLE RULES;

DROP SHARDING BROADCAST TABLE RULES t_b;

Sharding Scaling Rule

CREATE SHARDING SCALING RULE sharding_scaling(
INPUT(
  WORKER_THREAD=40,
  BATCH_SIZE=1000
),
OUTPUT(
  WORKER_THREAD=40,
  BATCH_SIZE=1000
),
STREAM_CHANNEL(TYPE(NAME=MEMORY, PROPERTIES("block-queue-size"=10000))),
COMPLETION_DETECTOR(TYPE(NAME=IDLE, PROPERTIES("incremental-task-idle-minute-threshold"=30))),
DATA_CONSISTENCY_CHECKER(TYPE(NAME=DATA_MATCH, PROPERTIES("chunk-size"=1000)))
);

ENABLE SHARDING SCALING RULE sharding_scaling;

DISABLE SHARDING SCALING RULE sharding_scaling;

DROP SHARDING SCALING RULE sharding_scaling;