View cluster parameters

Both the system tenant and user tenants can view cluster parameters.

You can view cluster parameters in the following ways:

• View cluster parameters by using the SHOW statement

  You can view all parameters and their descriptions in the cluster except for hidden parameters (parameters in the _xx_xx format). If the value of a hidden parameter has been modified to a non-default value, you can also use the SHOW statement to view it.

• View cluster parameters by using the GV$OB_PARAMETERS view

  Unlike the SHOW statement, the GV$OB_PARAMETERS view allows you to view all parameters in the cluster (including hidden parameters, that is, parameters in the _xx_xx format) and their descriptions.

For more information about parameters, see Overview of parameters and system variables.

View cluster parameters by using the SHOW statement

Both the system tenant (that is, the sys tenant) and user tenants can use the SHOW statement to view the values of cluster parameters. The system tenant can also specify the TENANT keyword to view the parameter information of a specified tenant.

1. Log in to the cluster as the system tenant or a user tenant.

   The following is an example connection string. Please refer to your actual database configuration when connecting to the database.

   obclient -h10.xx.xx.xx -P2883 -utest@mysql#obdemo -p***** -A
   

   For more detailed instructions on how to connect to a database, see Overview of database connections (MySQL-compatible mode) and Overview of database connections (Oracle-compatible mode).

2. Execute the following statement to view the cluster parameters.

   The statement is as follows:

   obclient [xxx]> SHOW PARAMETERS [SHOW_PARAM_OPTS] [TENANT = tenant_name];
   

   Where:

   • [SHOW_PARAM_OPTS] can be specified as [LIKE 'pattern' | WHERE expr]. The column attributes that can be specified in WHERE expr are the same as those in the result returned by SHOW PARAMETERS.

   • Specifying the TENANT keyword allows you to view the parameter information of a specified tenant.

   • The following is an example of querying parameters for the system tenant or a user tenant.

     obclient [(none)]> SHOW PARAMETERS LIKE '%syslog_level%';
     

     The query result is as follows:

     +-------+----------+----------------+----------+--------------+-----------+-------+------------------------------------------------------------------------------------------------------------------------------+----------+---------+---------+-------------------+---------------+-----------+
     | zone  | svr_type | svr_ip         | svr_port | name         | data_type | value | info                                                                                                                         | section  | scope   | source  | edit_level        | default_value | isdefault |
     +-------+----------+----------------+----------+--------------+-----------+-------+------------------------------------------------------------------------------------------------------------------------------+----------+---------+---------+-------------------+---------------+-----------+
     | zone1 | observer | 172.xx.xxx.xxx |     2882 | syslog_level | STRING    | WDIAG | specifies the current level of logging. There are DEBUG, TRACE, WDIAG, EDIAG, INFO, WARN, ERROR, seven different log levels. | OBSERVER | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE | WDIAG         |         1 |
     +-------+----------+----------------+----------+--------------+-----------+-------+------------------------------------------------------------------------------------------------------------------------------+----------+---------+---------+-------------------+---------------+-----------+
     1 row in set
     

   • The following example shows how to query the parameters of a specified tenant from the system tenant.

     obclient [(none)]> SHOW PARAMETERS LIKE '%syslog_level%' TENANT = mysql001;
     

     The query result is as follows:

     +-------+----------+----------------+----------+--------------+-----------+-------+------------------------------------------------------------------------------------------------------------------------------+----------+---------+---------+-------------------+---------------+-----------+
     | zone  | svr_type | svr_ip         | svr_port | name         | data_type | value | info                                                                                                                         | section  | scope   | source  | edit_level        | default_value | isdefault |
     +-------+----------+----------------+----------+--------------+-----------+-------+------------------------------------------------------------------------------------------------------------------------------+----------+---------+---------+-------------------+---------------+-----------+
     | zone1 | observer | 172.xx.xxx.xxx |     2882 | syslog_level | STRING    | WDIAG | specifies the current level of logging. There are DEBUG, TRACE, WDIAG, EDIAG, INFO, WARN, ERROR, seven different log levels. | OBSERVER | CLUSTER | DEFAULT | DYNAMIC_EFFECTIVE | WDIAG         |         1 |
     +-------+----------+----------------+----------+--------------+-----------+-------+------------------------------------------------------------------------------------------------------------------------------+----------+---------+---------+-------------------+---------------+-----------+
     1 row in set
     

   The following table describes the columns in the query result.

   Column	Description
   zone	The zone where the parameter is located.
   svr_type	The server type.
   svr_ip	The IP address of the server.
   svr_port	The port number of the server.
   name	The name of the parameter.
   data_type	The data type of the parameter, for example, STRING and CAPACITY.
   value	The value of the parameter. Note When you modify the value of a parameter, you can specify which zones or servers are affected by the change. Therefore, the value of the parameter may be different on different zones or servers.
   info	The description of the parameter.
   section	The category to which the parameter belongs: SSTABLE: indicates that the parameter is related to SSTables. OBSERVER: indicates that the parameter is related to OBServers. ROOT_SERVICE: indicates that the parameter is related to Root Services. TENANT: indicates that the parameter is related to tenants. TRANS: indicates that the parameter is related to transactions. LOAD_BALANCE: indicates that the parameter is related to load balancing. DAILY_MERGE: indicates that the parameter is related to major compactions. CLOG: indicates that the parameter is related to clogs. LOCATION_CACHE: indicates that the parameter is related to location caching. CACHE: indicates that the parameter is related to caching. RPC: indicates that the parameter is related to RPCs. OBPROXY: indicates that the parameter is related to OBProxies.
   scope	The scope of the parameter: TENANT: indicates that the parameter is at the tenant level. CLUSTER: indicates that the parameter is at the cluster level.
   source	The source of the current value: TENANT CLUSTER CMDLINE OBADMIN FILE DEFAULT
   edit_level	Defines the modification behavior of the parameter: READONLY: indicates that the parameter cannot be modified. STATIC_EFFECTIVE: indicates that the parameter can be modified but takes effect only after you restart the OBServer node. DYNAMIC_EFFECTIVE: indicates that the parameter can be modified and takes effect immediately.
   default_value	The default value of the parameter.
   isdefault	Indicates whether the current value is the default value. 0: The current value is not the default value. 1: The current value is the default value.

View cluster parameters through the GV$OB_PARAMETERS view

1. Log in to the cluster from the system tenant or a user tenant.

   The following is an example of how to connect to a database. Please use the actual environment settings when connecting to the database.

   obclient -h10.xx.xx.xx -P2883 -utest@mysql#obdemo -p***** -A
   

   For more information about how to connect to a database, see Overview of database connections (MySQL-compatible mode) and Overview of database connections (Oracle-compatible mode).

2. Run the following command to enter the oceanbase database.

   obclient > USE oceanbase;
   

   Note

   This step is required only for MySQL tenants. Oracle tenants can skip it.

3. Run the following command to view the cluster parameters.

   The following is an example query:

   obclient> SELECT * FROM GV$OB_PARAMETERS WHERE NAME LIKE '%syslog_level%';
   

   The query result is as follows:

   +----------------+----------+-------+---------+-----------+--------------+-----------+-------+------------------------------------------------------------------------------------------------------------------------------+----------+-------------------+---------------+-----------+
   | SVR_IP         | SVR_PORT | ZONE  | SCOPE   | TENANT_ID | NAME         | DATA_TYPE | VALUE | INFO                                                                                                                         | SECTION  | EDIT_LEVEL        | DEFAULT_VALUE | ISDEFAULT |
   +----------------+----------+-------+---------+-----------+--------------+-----------+-------+------------------------------------------------------------------------------------------------------------------------------+----------+-------------------+---------------+-----------+
   | 172.xx.xxx.xxx |     2882 | zone1 | CLUSTER |      NULL | syslog_level | STRING    | WDIAG | specifies the current level of logging. There are DEBUG, TRACE, WDIAG, EDIAG, INFO, WARN, ERROR, seven different log levels. | OBSERVER | DYNAMIC_EFFECTIVE | WDIAG         | YES       |
   +----------------+----------+-------+---------+-----------+--------------+-----------+-------+------------------------------------------------------------------------------------------------------------------------------+----------+-------------------+---------------+-----------+
   1 row in set
   

For more information about the GV$OB_PARAMETERS view, see GV$OB_PARAMETERS (MySQL-compatible mode).

References

For more information about cluster parameters, see the following topics:

• Cluster parameters

• Modify cluster parameters

• Reset cluster parameters

• Tenant system variables

For detailed information about each parameter, see Overview of parameters and system variables.