22.5.10.9 The ndbinfo config_values Table

Table des matières

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:

SELECT v.node_id AS 'Node Id',
p.param_name AS 'Parameter',
v.config_value AS 'Value'
FROM config_values v
JOIN config_params p
ON v.config_param=p.param_number
WHERE 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)

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:

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 Current
FROM config_params p
JOIN config_values v
ON p.param_number = v.config_param
WHERE 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: 48
Required: 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: 4294967039
Required: N
Current: 0
*************************** 4. row ***************************
Name: NoOfReplicas
Node: 2
Type: unsigned
Default: 2
Minimum: 1
Maximum: 4
Required: N
Current: 2
*************************** 5. row ***************************
Name: DataMemory
Node: 2
Type: unsigned
Default: 102760448
Minimum: 1048576
Maximum: 1099511627776
Required: N
Current: 524288000
*************************** 6. row ***************************
Name: NodeId
Node: 3
Type: unsigned
Default:
Minimum: 1
Maximum: 48
Required: 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: 4294967039
Required: N
Current: 0
*************************** 9. row ***************************
Name: NoOfReplicas
Node: 3
Type: unsigned
Default: 2
Minimum: 1
Maximum: 4
Required: N
Current: 2
*************************** 10. row ***************************
Name: DataMemory
Node: 3
Type: unsigned
Default: 102760448
Minimum: 1048576
Maximum: 1099511627776
Required: N
Current: 524288000
10 rows in set (0.01 sec)

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Document créé le 26/06/2006, dernière modification le 26/10/2018
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