Database Discovery

Database Discovery #

Syntax	Description	Type
CREATE DB_DISCOVERY RULE ruleDefinition [, ruleDefinition] …	Create database discovery rule	RDL
ALTER DB_DISCOVERY RULE ruleDefinition [, ruleDefinition] …	Modify database discovery rule	RDL
DROP DB_DISCOVERY RULE ruleName [, ruleName] …	Delete database discovery rule	RDL
DROP DB_DISCOVERY TYPE discoveryTypeName [, discoveryTypeName] …	Delete database discovery type	RDL
DROP DB_DISCOVERY HEARTBEAT discoveryHeartbeatName [, discoveryHeartbeatName] …	Delete database discovery listening heartbeat algorithm	RDL
SHOW DB_DISCOVERY RULES [FROM databaseName]	View database discovery rule	RQL
SHOW DB_DISCOVERY TYPES [FROM databaseName]	View database discovery type	RQL
SHOW DB_DISCOVERY HEARTBEATS [FROM databaseName]	View database discovery listening heartbeat algorithm	RQL
COUNT DB_DISCOVERY RULE	Count the number of database discovery rules, this syntax will be deprecated in subsequent versions	RQL

1. Create Database Discovery Rule #

CREATE DB_DISCOVERY RULE ruleDefinition [, ruleDefinition] ...

ruleDefinition:
    ruleName (storageUnits, typeDefinition, heartbeatDefinition)

storageUnits:
    STORAGE_UNITS(storageUnitName [, storageUnitName] ...)

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

heartbeatDefinition
    HEARTBEAT (PROPERTIES (properties)) 

properties:
    property [, property] ...

property:
    key=value

Parameter Description

Name	Data type	Description
discoveryTypeName	IDENTIFIER	Database discovery type name
ruleName	IDENTIFIER	Rule name
discoveryHeartbeatName	IDENTIFIER	Listening heartbeat name
typeName	STRING	Database discovery type, such as: MySQL.MGR
storageUnitName	IDENTIFIER	Data source name

discoveryType specifies the database discovery service type, DBPlusEngine has built-in support for MySQL.NORMAL_REPLICATION、MySQL.MGR、openGauss.NORMAL_REPLICATION、SphereEx:GaussDB_for_MySQL.NORMAL_REPLICATION、SphereEx:PostgreSQL.NORMAL_REPLICATION, details refers to built-in db-discovery algorithm;
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 (
STORAGE_UNITS(ds_0, ds_1, ds_2),
TYPE(NAME='MySQL.MGR',PROPERTIES('group-name'='92504d5b-6dec')),
HEARTBEAT(PROPERTIES('keep-alive-cron'='0/5 * * * * ?'))
);

2. Modify Database Discovery Rule #

ALTER DB_DISCOVERY RULE ruleDefinition [, ruleDefinition] ...

ruleDefinition:
    ruleName (storageUnits, typeDefinition, heartbeatDefinition)

storageUnits:
    STORAGE_UNITS(storageUnitName [, storageUnitName] ...)

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

heartbeatDefinition
    HEARTBEAT (PROPERTIES (properties)) 

properties:
    property [, property] ...

property:
    key=value

Parameter Description

Name	Data type	Description
discoveryTypeName	IDENTIFIER	Database discovery type name
ruleName	IDENTIFIER	Rule name
discoveryHeartbeatName	IDENTIFIER	Listening heartbeat name
typeName	STRING	Database discovery type, such as: MySQL.MGR
storageUnitName	IDENTIFIER	Data source name

discoveryType specifies the database discovery service type, DBPlusEngine has built-in support for MySQL.NORMAL_REPLICATION、MySQL.MGR、openGauss.NORMAL_REPLICATION、SphereEx:GaussDB_for_MySQL.NORMAL_REPLICATION、SphereEx:PostgreSQL.NORMAL_REPLICATION, details refers to built-in db-discovery algorithm;
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 altering a discoveryRule, modify both discoveryType and discoveryHeartbeat

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

3. Delete Database Discovery Rule #

DROP DB_DISCOVERY RULE ruleName [, ruleName] ...

Parameter Description

Name	Data type	Description
ruleName	IDENTIFIER	Rule name

Removing a discoveryRule does not remove the discoveryType and discoveryHeartbeat used by the discoveryRule.

Example

DROP DB_DISCOVERY RULE db_discovery_group_0;

4. Delete Database Discovery Type #

DROP DB_DISCOVERY TYPE discoveryTypeName [, discoveryTypeName] ...

Parameter Description

Name	Data type	Description
discoveryTypeName	IDENTIFIER	Database discovery type name
typeName	STRING	Database discovery type, such as: MySQL.MGR

Removing a discoveryRule does not remove the discoveryType and discoveryHeartbeat used by the discoveryRule.

Example

DROP DB_DISCOVERY TYPE db_discovery_group_0_mgr;

5. Delete Database Discovery Listening Heartbeat #

DROP DB_DISCOVERY HEARTBEAT discoveryHeartbeatName [, discoveryHeartbeatName] ...

Parameter Description

Name	Data type	Description
discoveryHeartbeatName	IDENTIFIER	Listening heartbeat name

Example

DROP DB_DISCOVERY HEARTBEAT db_discovery_group_0_heartbeat;

6. View Database Discovery Rule #

SHOW DB_DISCOVERY RULES [FROM databaseName]

Parameter Description

Name	Data type	Description
databaseName	IDENTIFIER	Logical database name

Example

View database discovery rules

mysql> SHOW DB_DISCOVERY RULES;
+----------------------+-------------------+--------------------------+-----------------------------------------------------------------------------------+------------------------------------------------------------------------------+
| group_name           | data_source_names | primary_data_source_name | discovery_type                                                                    | discovery_heartbeat                                                          |
+----------------------+-------------------+--------------------------+-----------------------------------------------------------------------------------+------------------------------------------------------------------------------+
| db_discovery_group_0 | ds_0,ds_1,ds_2    |        ds_0              | {name=db_discovery_group_0_mgr, type=MySQL.MGR, props={group-name=92504d5b-6dec}} | {name=db_discovery_group_0_heartbeat, props={keep-alive-cron=0/5 * * * * ?}} |
+----------------------+-------------------+--------------------------+-----------------------------------------------------------------------------------+-----------------------------------------------------------------------------+
1 row in set (0.20 sec)

Output Description

Column	Description
group_name	Rule name
data_source_names	Data source name list
primary_data_source_name	Primary data source name
discovery_type	Database discovery service type
discovery_heartbeat	Database discovery service heartbeat

7. View Database Discovery Type #

SHOW DB_DISCOVERY TYPES [FROM databaseName]

Parameter Description

Name	Data type	Description
databaseName	IDENTIFIER	Logical database name

Example

View all database discovery type for current logical database

mysql> SHOW DB_DISCOVERY TYPES;
+--------------------------+------------+----------------------------+
| name                     | type       | props                      |
+--------------------------+------------+----------------------------+
| db_discovery_group_0_mgr | MySQL.MGR  | {group-name=92504d5b-6dec} |
+--------------------------+------------+----------------------------+
1 row in set (0.01 sec)

Output Description

Column	Description
name	Discovery type name
type	Discovery type type
props	Discovery type properties

8. View Database Discovery Listening Heartbeat #

SHOW DB_DISCOVERY HEARTBEATS [FROM databaseName]

Parameter Description

Name	Data type	Description
databaseName	IDENTIFIER	Logical database name

Example

View all database heartbeat for current logical database

mysql> SHOW DB_DISCOVERY HEARTBEATS;
+--------------------------------+---------------------------------+
| name                           | props                           |
+--------------------------------+---------------------------------+
| db_discovery_group_0_heartbeat | {keep-alive-cron=0/5 * * * * ?} |
+---------------------------------+---------------------------------+
1 row in set (0.01 sec)

Output Description

Column	Description
name	Heartbeat name
props	Heartbeat properties