CREATE READWRITE_SPLITTING RULE

描述

。 CREATE READWRITE_SPLITTING RULE 语法用于创建读写分离规则。

语法定义

语法 铁路图

CreateReadwriteSplittingRule ::=
  'CREATE' 'READWRITE_SPLITTING' 'RULE' ifNotExists? readwriteSplittingDefinition (',' readwriteSplittingDefinition)*
ifNotExists ::=
  'IF' 'NOT' 'EXISTS'
readwriteSplittingDefinition ::=
  ruleName '(' dataSourceDefinition (',' transactionalReadQueryStrategyDefinition)? (',' loadBalancerDefinition)? ')'
dataSourceDefinition ::=
    'WRITE_STORAGE_UNIT' '=' writeStorageUnitName ',' 'READ_STORAGE_UNITS' '(' storageUnitName (',' storageUnitName)* ')' 
transactionalReadQueryStrategyDefinition ::=
    'TRANSACTIONAL_READ_QUERY_STRATEGY' '=' transactionalReadQueryStrategyType
loadBalancerDefinition ::=
    'TYPE' '(' 'NAME' '=' loadBalancerType (',' propertiesDefinition)? ')'
ruleName ::=
  identifier
writeStorageUnitName ::=
  identifier
storageUnitName ::=
  identifier
transactionalReadQueryStrategyType ::=
  string
loadBalancerType ::=
  string
propertiesDefinition ::=
  'PROPERTIES' '(' key '=' value (',' key '=' value)* ')'
key ::=
  string
value ::=
  literal

补充说明

• transactionalReadQueryStrategyType 指定事务内读请求路由策略，请参考YAML 配置；
• loadBalancerType 指定负载均衡算法类型，请参考负载均衡算法；
• 重复的 ruleName 将无法被创建；
• ifNotExists 子句用于避免出现 Duplicate readwrite_splitting rule 错误。

示例

创建读写分离规则

CREATE READWRITE_SPLITTING RULE ms_group_0 (
    WRITE_STORAGE_UNIT=write_ds,
    READ_STORAGE_UNITS(read_ds_0,read_ds_1),
    TYPE(NAME="random")
);

使用 ifNotExists 子句创建读写分离规则

• 读写分离规则

CREATE READWRITE_SPLITTING RULE IF NOT EXISTS ms_group_0 (
    WRITE_STORAGE_UNIT=write_ds,
    READ_STORAGE_UNITS(read_ds_0,read_ds_1),
    TYPE(NAME="random")
);

保留字

CREATE、READWRITE_SPLITTING、RULE、WRITE_STORAGE_UNIT、READ_STORAGE_UNITS 、TYPE、NAME、PROPERTIES、TRUE、FALSE

相关链接

• 保留字
• 负载均衡算法