Spec-Zone .ru
спецификации, руководства, описания, API
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Spec-Zone .ru
спецификации, руководства, описания, API
|
Querying this table provides information similar to that provided by the ALL REPORT
MemoryUsage command in the ndb_mgm client, or logged by ALL DUMP
1000.
The following table provides information about the columns in the memoryusage
table. For each column, the table shows the name, data type, and a brief description. Additional information can
be found in the notes following the table.
| Column Name | Type | Remarks |
|---|---|---|
node_id |
integer | The node ID of this data node. |
memory_type |
string | One of DATA_MEMORY or INDEX_MEMORY. |
used |
integer | Number of bytes currently used for data memory or index memory by this data node. |
used_pages |
integer | Number of pages currently used for data memory or index memory by this data node; see text. |
total |
integer | Total number of bytes of data memory or index memory available for this data node; see text. |
total_pages |
integer | Total number of memory pages available for data memory or index memoryon this data node; see text. |
The total column represents the total amount of memory in bytes available for the
given resource (data memory or index memory) on a particular data node. This number should be approximately
equal to the setting of the corresponding configuration parameter in the config.ini file.
Suppose that the cluster has 2 data nodes having node IDs 1 and 2, and the config.ini file contains the following:
[ndbd default]DataMemory = 100MIndexMemory = 100M
The following query shows approximately the same values:
mysql>SELECT node_id, memory_type, total>FROM ndbinfo.memoryusage;+---------+--------------+-----------+| node_id | memory_type | total |+---------+--------------+-----------+| 1 | Data memory | 104857600 || 1 | Index memory | 105119744 || 2 | Data memory | 104857600 || 2 | Index memory | 105119744 |+---------+--------------+-----------+4 rows in set (0.30 sec)
In this case, the total column values for index memory are slightly higher than the
value set of IndexMemory
due to internal rounding.
For the used_pages and total_pages columns, resources
are measured in pages, which are 32K in size for DataMemory and 8K for IndexMemory.