DB Discovery

Syntax

CREATE DB_DISCOVERY RULE ruleDefinition [, ruleDefinition] ...

ALTER DB_DISCOVERY RULE ruleDefinition [, ruleDefinition] ...

DROP DB_DISCOVERY RULE ruleName [, ruleName] ...

CREATE DB_DISCOVERY TYPE databaseDiscoveryTypeDefinition [, databaseDiscoveryTypeDefinition] ...

ALTER DB_DISCOVERY TYPE databaseDiscoveryTypeDefinition [, databaseDiscoveryTypeDefinition] ...

DROP DB_DISCOVERY TYPE discoveryTypeName [, discoveryTypeName] ...

CREATE DB_DISCOVERY HEARTBEAT databaseDiscoveryHeartbaetDefinition [, databaseDiscoveryHeartbaetDefinition] ...

ALTER DB_DISCOVERY HEARTBEAT databaseDiscoveryHeartbaetDefinition [, databaseDiscoveryHeartbaetDefinition] ...

DROP DB_DISCOVERY HEARTBEAT discoveryHeartbeatName [, discoveryHeartbeatName] ...

ruleDefinition:
    (databaseDiscoveryRuleDefinition | databaseDiscoveryRuleConstruction)

databaseDiscoveryRuleDefinition
    ruleName (resources, typeDefinition, heartbeatDefinition)

databaseDiscoveryRuleConstruction
    ruleName (resources, TYPE = discoveryTypeName, HEARTBEAT = discoveryHeartbeatName)

databaseDiscoveryTypeDefinition
    discoveryTypeName (typeDefinition)

databaseDiscoveryHeartbaetDefinition
    discoveryHeartbeatName (PROPERTIES (properties)) 

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

typeDefinition:
    TYPE(NAME=typeName [, PROPERTIES([properties] )] )

heartbeatDefinition
    HEARTBEAT (PROPERTIES (properties)) 

properties:
    property [, property] ...

property:
    key=value
  • discoveryType specifies the database discovery service type, ShardingSphere has built-in support for MGR
  • Duplicate ruleName will not be created
  • The discoveryType and discoveryHeartbeat being used cannot be deleted
  • Names with - need to use " " when changing
  • When removing the discoveryRule, the discoveryType and discoveryHeartbeat used by the discoveryRule will not be removed

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=mgr,PROPERTIES('group-name'='92504d5b-6dec')),
HEARTBEAT(PROPERTIES('keep-alive-cron'='0/5 * * * * ?'))
);

ALTER DB_DISCOVERY RULE db_discovery_group_0 (
RESOURCES(ds_0, ds_1, ds_2),
TYPE(NAME=mgr,PROPERTIES('group-name'='246e9612-aaf1')),
HEARTBEAT(PROPERTIES('keep-alive-cron'='0/5 * * * * ?'))
);

DROP DB_DISCOVERY RULE db_discovery_group_0;

DROP DB_DISCOVERY TYPE db_discovery_group_0_mgr;

DROP DB_DISCOVERY HEARTBEAT db_discovery_group_0_heartbeat;

Use the existing discoveryType and discoveryHeartbeat to create a discoveryRule

CREATE DB_DISCOVERY TYPE db_discovery_group_1_mgr(
  TYPE(NAME=mgr,PROPERTIES('group-name'='92504d5b-6dec'))
);

CREATE DB_DISCOVERY HEARTBEAT db_discovery_group_1_heartbeat(
  PROPERTIES('keep-alive-cron'='0/5 * * * * ?')
);

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
);

ALTER DB_DISCOVERY TYPE db_discovery_group_1_mgr(
  TYPE(NAME=mgr,PROPERTIES('group-name'='246e9612-aaf1'))
);

ALTER DB_DISCOVERY HEARTBEAT db_discovery_group_1_heartbeat(
  PROPERTIES('keep-alive-cron'='0/10 * * * * ?')
);

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

DROP DB_DISCOVERY RULE db_discovery_group_1;

DROP DB_DISCOVERY TYPE db_discovery_group_1_mgr;

DROP DB_DISCOVERY HEARTBEAT db_discovery_group_1_heartbeat;