This table provides information about data node resource availability and usage.
These resources are sometimes known as super-pools.
The following table provides information about the columns in
the resources 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 | Description |
|---|---|---|
node_id | integer | The unique node ID of this data node. |
resource_name | string | Name of the resource; see text. |
reserved | integer | The amount reserved for this resource. |
used | integer | The amount actually used by this resource. |
max | integer | The maximum amount of this resource used, since the node was last started. |
The resource_name can be one of the names
shown in the following table:
| Resource name | Description |
|---|---|
RESERVED | Reserved by the system; cannot be overridden. |
DISK_OPERATIONS | If a log file group is allocated, the size of the undo log buffer is
used to set the size of this resource. This resource is
used only to allocate the undo log buffer for an undo
log file group; there can only be one such group.
Overallocation occurs as needed by
CREATE LOGFILE GROUP. |
DISK_RECORDS | Records allocated for Disk Data operations. |
DATA_MEMORY | Used for main memory tuples, indexes, and hash indexes. Sum of DataMemory and IndexMemory, plus 8 pages of 32 KB each if IndexMemory has been set. Cannot be overallocated. |
JOBBUFFER | Used for allocating job buffers by the NDB scheduler; cannot be overallocated. This is approximately 2 MB per thread plus a 1 MB buffer in both directions for all threads that can communicate. For large configurations this consume several GB. |
FILE_BUFFERS | Used by the redo log handler in the DBLQH kernel
block; cannot be overallocated. Size is
NoOfFragmentLogParts
* RedoBuffer,
plus 1 MB per log file part. |
TRANSPORTER_BUFFERS | Used for send buffers by ndbmtd; the sum of
TotalSendBufferMemory
and
ExtraSendBufferMemory.
This resource that can be overallocated by up to 25
percent. TotalSendBufferMemory is
calculated by summing the send buffer memory per node,
the default value of which is 2 MB. Thus, in a system
having four data nodes and eight API nodes, the data
nodes have 12 * 2 MB send buffer memory.
ExtraSendBufferMemory is used by
ndbmtd and amounts to 2 MB extra
memory per thread. Thus, with 4 LDM threads, 2 TC
threads, 1 main thread, 1 replication thread, and 2
receive threads,
ExtraSendBufferMemory is 10 * 2 MB.
Overallocation of this resource can be performed by
setting the
SharedGlobalMemory
data node configuration parameter. |
DISK_PAGE_BUFFER | Used for the disk page buffer; determined by the
DiskPageBufferMemory
configuration parameter. Cannot be overallocated. |
QUERY_MEMORY | Used by the DBSPJ kernel block. |
SCHEMA_TRANS_MEMORY | Minimum is 2 MB; can be overallocated to use any remaining available memory. |