Sharding Algorithm #

Auto Sharding Algorithm #

Modulo Sharding Algorithm #

Type: MOD

Attributes:

Name	DataType	Description
sharding-count	int	Sharding count

Hash Modulo Sharding Algorithm #

Type: HASH_MOD

Attributes:

Name	DataType	Description
sharding-count	int	Sharding count

Volume Based Range Sharding Algorithm #

Type: VOLUME_RANGE

Attributes:

Name	DataType	Description
range-lower	long	Range lower bound, throw exception if lower than bound
range-upper	long	Range upper bound, throw exception if upper than bound
sharding-volume	long	Sharding volume

Boundary Based Range Sharding Algorithm #

Type: BOUNDARY_RANGE

Attributes:

Name	DataType	Description
sharding-ranges	String	Range of sharding border, multiple boundaries separated by commas

Auto Interval Sharding Algorithm #

Type: AUTO_INTERVAL

Attributes:

Name	DataType	Description
datetime-lower	String	Shard datetime begin boundary, pattern: yyyy-MM-dd HH:mm:ss
datetime-upper	String	Shard datetime end boundary, pattern: yyyy-MM-dd HH:mm:ss
sharding-seconds	long	Max seconds for the data in one shard, allows sharding key timestamp format seconds with time precision, but time precision after seconds is automatically erased

Consistent Hash Sharding Algorithm #

Type: SphereEx:CONSISTENT_HASH

Attributes:

Name	DataType	Description
sharding-count	int	Required item, used to specify the number of sharding.
sharding-node-weight	String	It is not a required item. The weight of sharding data nodes is separated by commas, for example: “2,2,1,1”. The larger the weight, the more virtual nodes used for consistency hash calculation, and the default weight is 1.
virtual-node-count	int	Required item. The number of virtual nodes corresponding to the sharding data node. The more virtual nodes, the more balanced the sharding. But too many virtual nodes will also affect the performance.
consistent-hash-seed	int	It is not required. The seed parameter of consistency hash is calculated. The default value is 0.

Standard Sharding Algorithm #

Apache ShardingSphere built-in standard sharding algorithm are:

Inline Sharding Algorithm #

With Groovy expressions, InlineShardingStrategy provides single-key support for the sharding operation of = and IN in SQL. Simple sharding algorithms can be used through a simple configuration to avoid laborious Java code developments. For example, t_user_$->{u_id % 8} means table t_user is divided into 8 tables according to u_id, with table names from t_user_0 to t_user_7. Please refer to Inline Expression for more details.

Type: INLINE

Attributes:

Name	DataType	Description	Default Value
algorithm-expression	String	Inline expression sharding algorithm	-
allow-range-query-with-inline-sharding (?)	boolean	Whether range query is allowed. Note: range query will ignore sharding strategy and conduct full routing	false

Interval Sharding Algorithm #

Type: INTERVAL

Attributes:

Name	DataType	Description	Default Value
datetime-pattern	String	Timestamp pattern of sharding value, must can be transformed to Java LocalDateTime. For example: yyyy-MM-dd HH:mm:ss	-
datetime-lower	String	Datetime sharding lower boundary, pattern is defined `datetime-pattern`	-
datetime-upper (?)	String	Datetime sharding upper boundary, pattern is defined `datetime-pattern`	Now
sharding-suffix-pattern	String	Suffix pattern of sharding data sources or tables, must can be transformed to Java LocalDateTime, must be consistent with `datetime-interval-unit`. For example: yyyyMM	-
datetime-interval-amount (?)	int	Interval of sharding value	1
datetime-interval-unit (?)	String	Unit of sharding value interval, must can be transformed to Java ChronoUnit’s Enum value. For example: MONTHS	DAYS

Complex Sharding Algorithm #

Complex Inline Sharding Algorithm #

Please refer to Inline Expression for more details.

Type: COMPLEX_INLINE

Name	DataType	Description	Default Value
sharding-columns (?)	String	sharing column names	-
algorithm-expression	String	Inline expression sharding algorithm	-
allow-range-query-with-inline-sharding (?)	boolean	Whether range query is allowed. Note: range query will ignore sharding strategy and conduct full routing	false

Hint Sharding Algorithm #

Hint Inline Sharding Algorithm #

Please refer to Inline Expression for more details.

Type: COMPLEX_INLINE

Name	DataType	Description	Default Value
algorithm-expression	String	Inline expression sharding algorithm	${value}

Class Based Sharding Algorithm #

Realize custom extension by configuring the sharding strategy type and algorithm class name.

Type：CLASS_BASED

Attributes：

Name	DataType	Description
strategy	String	Sharding strategy type, support STANDARD, COMPLEX or HINT (case insensitive)
algorithmClassName	String	Fully qualified name of sharding algorithm