MySQL 8.4 Release Notes
25.6.17.12 ndbinfo config_values 表
表config_values
提供了节点配置参数当前状态的信息。每一行对应于某个节点上的当前参数值。
表config_values
包含以下列:
-
node_id
集群中的节点ID
-
config_param
参数的内部ID号
-
config_value
参数当前值
该表的config_param
列和config_params
表的param_number
列使用相同的参数标识符。通过将这两个表连接在这些列上,您可以获得关于所需节点配置参数的详细信息。以下查询提供了每个数据节点在集群中的当前值,按节点ID和参数名称排序:
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;
从前一个查询中部分输出结果,当在用于简单测试的小型示例集群上运行时:
+---------+------------------------------------------+----------------+
| 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)
WHERE子句过滤掉以双下划线(__
)开头的参数名称,这些参数是NDB开发者保留的,用于测试和其他内部使用,不适合在生产环境中使用NDB集群。
可以通过发出适当的查询来获得更具体、更详细或两者的输出。这一例子提供了当前对所有数据节点在集群中的NodeId
、NoOfReplicas
、HostName
、DataMemory
、IndexMemory
和TotalSendBufferMemory
参数的所有类型信息。
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
在运行于小型 NDB 集群(用于简单测试)的数据节点 2 个时,这个查询的输出结果如下所示:
*************************** 1. row ***************************
Name: NodeId
Node: 2
Type: unsigned
Default:
Minimum: 1
Maximum: 144
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: 144
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)