CREATE DB_DISCOVERY RULE

Description

The CREATE DB_DISCOVERY RULE syntax is used to create a database discovery rule.

Syntax

CreateDatabaseDiscoveryRule ::=
  'CREATE' 'DB_DISCOVERY' 'RULE' ( databaseDiscoveryDefinition | databaseDiscoveryConstruction ) ( ',' ( databaseDiscoveryDefinition | databaseDiscoveryConstruction ) )*
databaseDiscoveryDefinition ::=
    ruleName '(' 'RESOURCES' '(' resourceName ( ',' resourceName )* ')' ',' 'TYPE' '(' 'NAME' '=' typeName ( ',' 'PROPERTIES' 'key' '=' 'value' ( ',' 'key' '=' 'value' )* )? ',' 'HEARTBEAT' '(' 'key' '=' 'value' ( ',' 'key' '=' 'value' )* ')' ')' 
databaseDiscoveryConstruction ::=
    ruleName '(' 'RESOURCES' '(' resourceName ( ',' resourceName )* ')' ',' 'TYPE' '=' discoveryTypeName ',' 'HEARTBEAT' '=' discoveryHeartbeatName ')'
ruleName ::=
  identifier
resourceName ::=
  identifier
typeName ::=
  identifier
discoveryHeartbeatName ::=
  identifier

Supplement

• discoveryType specifies the database discovery service type, ShardingSphere has built-in support for MySQL.MGR;
• Duplicate ruleName will not be created.

Example

When creating a discoveryRule, create both discoveryType and discoveryHeartbeat

CREATE
DB_DISCOVERY RULE db_discovery_group_0 (
    RESOURCES(ds_0, ds_1, ds_2),
    TYPE(NAME='MySQL.MGR',PROPERTIES('group-name'='92504d5b-6dec')),
    HEARTBEAT(PROPERTIES('keep-alive-cron'='0/5 * * * * ?'))
);

Use the existing discoveryType and discoveryHeartbeat to create a discoveryRule

CREATE
DB_DISCOVERY RULE db_discovery_group_1 (
    RESOURCES(ds_0, ds_1, ds_2),
    TYPE=db_discovery_group_1_mgr,
    HEARTBEAT=db_discovery_group_1_heartbeat
);

Reserved word

CREATE, DB_DISCOVERY, RULE, RESOURCES, TYPE, NAME, PROPERTIES, HEARTBEAT

Related links

• Reserved word