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22.5.10.9 The ndbinfo config_values Table

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The config_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.

Table 22.383 Columns of the config_params table

Column Name Type Description
node_id integer ID of the node in the cluster
config_param integer The parameter's internal ID number
config_value string Current value of the parameter

This table's config_param column and the config_params table's param_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:

  1. SELECT    v.node_id AS 'Node Id',
  2.           p.param_name AS 'Parameter',
  3.           v.config_value AS 'Value'
  4. FROM      config_values v
  5. JOIN      config_params p
  6. ON        v.config_param=p.param_number
  7. WHERE     p.param_name NOT LIKE '\_\_%'
  8. 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:

  1. +---------+------------------------------------------+----------------+
  2. | Node Id | Parameter                                | Value          |
  3. +---------+------------------------------------------+----------------+
  4. |       2 | Arbitration                              | 1              |
  5. |       2 | ArbitrationTimeout                       | 7500           |
  6. |       2 | BackupDataBufferSize                     | 16777216       |
  7. |       2 | BackupDataDir                            | /home/jon/data |
  8. |       2 | BackupDiskWriteSpeedPct                  | 50             |
  9. |       2 | BackupLogBufferSize                      | 16777216       |
  10.  
  11. ...
  12.  
  13. |       3 | TotalSendBufferMemory                    | 0              |
  14. |       3 | TransactionBufferMemory                  | 1048576        |
  15. |       3 | TransactionDeadlockDetectionTimeout      | 1200           |
  16. |       3 | TransactionInactiveTimeout               | 4294967039     |
  17. |       3 | TwoPassInitialNodeRestartCopy            | 0              |
  18. |       3 | UndoDataBuffer                           | 16777216       |
  19. |       3 | UndoIndexBuffer                          | 2097152        |
  20. +---------+------------------------------------------+----------------+
  21. 248 rows in set (0.02 sec)

The WHERE 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 the NodeId, NoOfReplicas, HostName, DataMemory, IndexMemory, and TotalSendBufferMemory parameters as currently set for all data nodes in the cluster:

  1. SELECT  p.param_name AS Name,
  2.         v.node_id AS Node,
  3.         p.param_type AS Type,
  4.         p.param_default AS 'Default',
  5.         p.param_min AS Minimum,
  6.         p.param_max AS Maximum,
  7.         CASE p.param_mandatory WHEN 1 THEN 'Y' ELSE 'N' END AS 'Required',
  8.         v.config_value AS Current
  9. FROM    config_params p
  10. JOIN    config_values v
  11. ON      p.param_number = v.config_param
  12. WHERE   p. param_name
  13.   IN ('NodeId', 'NoOfReplicas', 'HostName',
  14.       '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. *************************** 1. row ***************************
  2.     Name: NodeId
  3.     Node: 2
  4.     Type: unsigned
  5.  Default:
  6.  Minimum: 1
  7.  Maximum: 48
  8. Required: Y
  9.  Current: 2
  10. *************************** 2. row ***************************
  11.     Name: HostName
  12.     Node: 2
  13.     Type: string
  14.  Default: localhost
  15.  Minimum:
  16.  Maximum:
  17. Required: N
  18.  Current: 127.0.0.1
  19. *************************** 3. row ***************************
  20.     Name: TotalSendBufferMemory
  21.     Node: 2
  22.     Type: unsigned
  23.  Default: 0
  24.  Minimum: 262144
  25.  Maximum: 4294967039
  26. Required: N
  27.  Current: 0
  28. *************************** 4. row ***************************
  29.     Name: NoOfReplicas
  30.     Node: 2
  31.     Type: unsigned
  32.  Default: 2
  33.  Minimum: 1
  34.  Maximum: 4
  35. Required: N
  36.  Current: 2
  37. *************************** 5. row ***************************
  38.     Name: DataMemory
  39.     Node: 2
  40.     Type: unsigned
  41.  Default: 102760448
  42.  Minimum: 1048576
  43.  Maximum: 1099511627776
  44. Required: N
  45.  Current: 524288000
  46. *************************** 6. row ***************************
  47.     Name: NodeId
  48.     Node: 3
  49.     Type: unsigned
  50.  Default:
  51.  Minimum: 1
  52.  Maximum: 48
  53. Required: Y
  54.  Current: 3
  55. *************************** 7. row ***************************
  56.     Name: HostName
  57.     Node: 3
  58.     Type: string
  59.  Default: localhost
  60.  Minimum:
  61.  Maximum:
  62. Required: N
  63.  Current: 127.0.0.1
  64. *************************** 8. row ***************************
  65.     Name: TotalSendBufferMemory
  66.     Node: 3
  67.     Type: unsigned
  68.  Default: 0
  69.  Minimum: 262144
  70.  Maximum: 4294967039
  71. Required: N
  72.  Current: 0
  73. *************************** 9. row ***************************
  74.     Name: NoOfReplicas
  75.     Node: 3
  76.     Type: unsigned
  77.  Default: 2
  78.  Minimum: 1
  79.  Maximum: 4
  80. Required: N
  81.  Current: 2
  82. *************************** 10. row ***************************
  83.     Name: DataMemory
  84.     Node: 3
  85.     Type: unsigned
  86.  Default: 102760448
  87.  Minimum: 1048576
  88.  Maximum: 1099511627776
  89. Required: N
  90.  Current: 524288000
  91. 10 rows in set (0.01 sec)

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Document created the 26/06/2006, last modified the 26/10/2018
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