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Theconfig_values table provides information about the current state of node configuration parameter values. Each row in the table corresponds to the current value of a parameter on a given node.

Theconfig_values table contains the following columns:

Notes

This table'sconfig_param column and theconfig_params table'sparam_number column use the same parameter identifiers. By joining the two tables on these columns, you can obtain detailed information about desired node configuration parameters. The query shown here provides the current values for all parameters on each data node in the cluster, ordered by node ID and parameter name:

SELECT    v.node_id AS 'Node Id',          p.param_name AS 'Parameter',          v.config_value AS 'Value'FROM      config_values vJOIN      config_params pON        v.config_param=p.param_numberWHERE     p.param_name NOT LIKE '\_\_%'ORDER BY  v.node_id, p.param_name;

Partial output from the previous query when run on a small example cluster used for simple testing:

+---------+------------------------------------------+----------------+| Node Id | Parameter                                | Value          |+---------+------------------------------------------+----------------+|       2 | Arbitration                              | 1              ||       2 | ArbitrationTimeout                       | 7500           ||       2 | BackupDataBufferSize                     | 16777216       ||       2 | BackupDataDir                            | /home/jon/data ||       2 | BackupDiskWriteSpeedPct                  | 50             ||       2 | BackupLogBufferSize                      | 16777216       |...|       3 | TotalSendBufferMemory                    | 0              ||       3 | TransactionBufferMemory                  | 1048576        ||       3 | TransactionDeadlockDetectionTimeout      | 1200           ||       3 | TransactionInactiveTimeout               | 4294967039     ||       3 | TwoPassInitialNodeRestartCopy            | 0              ||       3 | UndoDataBuffer                           | 16777216       ||       3 | UndoIndexBuffer                          | 2097152        |+---------+------------------------------------------+----------------+248 rows in set (0.02 sec)

TheWHERE clause filters out parameters whose names begin with a double underscore (__); these parameters are reserved for testing and other internal uses by the NDB developers, and are not intended for use in a production NDB Cluster.

You can obtain output that is more specific, more detailed, or both by issuing the proper queries. This example provides all types of available information about theNodeId,NoOfReplicas,HostName,DataMemory,IndexMemory, andTotalSendBufferMemory parameters as currently set for all data nodes in the cluster:

SELECT  p.param_name AS Name,        v.node_id AS Node,        p.param_type AS Type,        p.param_default AS 'Default',        p.param_min AS Minimum,        p.param_max AS Maximum,        CASE p.param_mandatory WHEN 1 THEN 'Y' ELSE 'N' END AS 'Required',        v.config_value AS CurrentFROM    config_params pJOIN    config_values vON      p.param_number = v.config_paramWHERE   p. param_name  IN ('NodeId', 'NoOfReplicas', 'HostName',      'DataMemory', 'IndexMemory', 'TotalSendBufferMemory')\G

The output from this query when run on a small NDB Cluster with 2 data nodes used for simple testing is shown here:

*************************** 1. row ***************************    Name: NodeId    Node: 2    Type: unsigned Default: Minimum: 1 Maximum: 144Required: Y Current: 2*************************** 2. row ***************************    Name: HostName    Node: 2    Type: string Default: localhost Minimum: Maximum:Required: N Current: 127.0.0.1*************************** 3. row ***************************    Name: TotalSendBufferMemory    Node: 2    Type: unsigned Default: 0 Minimum: 262144 Maximum: 4294967039Required: N Current: 0*************************** 4. row ***************************    Name: NoOfReplicas    Node: 2    Type: unsigned Default: 2 Minimum: 1 Maximum: 4Required: N Current: 2*************************** 5. row ***************************    Name: DataMemory    Node: 2    Type: unsigned Default: 102760448 Minimum: 1048576 Maximum: 1099511627776Required: N Current: 524288000*************************** 6. row ***************************    Name: NodeId    Node: 3    Type: unsigned Default: Minimum: 1 Maximum: 144Required: Y Current: 3*************************** 7. row ***************************    Name: HostName    Node: 3    Type: string Default: localhost Minimum: Maximum:Required: N Current: 127.0.0.1*************************** 8. row ***************************    Name: TotalSendBufferMemory    Node: 3    Type: unsigned Default: 0 Minimum: 262144 Maximum: 4294967039Required: N Current: 0*************************** 9. row ***************************    Name: NoOfReplicas    Node: 3    Type: unsigned Default: 2 Minimum: 1 Maximum: 4Required: N Current: 2*************************** 10. row ***************************    Name: DataMemory    Node: 3    Type: unsigned Default: 102760448 Minimum: 1048576 Maximum: 1099511627776Required: N Current: 52428800010 rows in set (0.01 sec)