This table provides information about data node resource availability and usage.
These resources are sometimes known as super-pools.
resources table contains the following
The unique node ID of this data node.
Name of the resource; see text.
The amount reserved for this resource, as a number of 32KB pages.
The amount actually used by this resource, as a number of 32KB pages.
The maximum amount (number of 32KB pages) of this resource used, since the node was last started.
resource_name can be any one of the names
shown in the following table:
RESERVED: Reserved by the system; cannot be overridden.
TRANSACTION_MEMORY: Memory allocated for transactions on this data node. In NDB 8.0.19 and later this can be controlled using the
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.
TRANSPORTER_BUFFERS: Used for send buffers by ndbmtd; the sum of
ExtraSendBufferMemory. This resource that can be overallocated by up to 25 percent.
TotalSendBufferMemoryis 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.
ExtraSendBufferMemoryis 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,
ExtraSendBufferMemoryis 10 * 2 MB. Overallocation of this resource can be performed by setting the
SharedGlobalMemorydata node configuration parameter.
DISK_PAGE_BUFFER: Used for the disk page buffer; determined by the
DiskPageBufferMemoryconfiguration parameter. Cannot be overallocated.
QUERY_MEMORY: Used by the
SCHEMA_TRANS_MEMORY: Minimum is 2 MB; can be overallocated to use any remaining available memory.