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MySQL 5.5 Reference Manual
Related Documentation Download this Manual Excerpts from this Manual The ndbinfo resources Table

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 NameTypeDescription
node_idintegerThe unique node ID of this data node.
resource_namestringName of the resource; see text.
reservedintegerThe amount reserved for this resource.
usedintegerThe amount actually used by this resource.
maxintegerThe 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 nameDescription
RESERVEDReserved by the system; cannot be overridden.
DISK_OPERATIONSIf 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_RECORDSRecords allocated for Disk Data operations.
DATA_MEMORYUsed 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.
JOBBUFFERUsed 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_BUFFERSUsed 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_BUFFERSUsed 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_BUFFERUsed for the disk page buffer; determined by the DiskPageBufferMemory configuration parameter. Cannot be overallocated.
QUERY_MEMORYUsed by the DBSPJ kernel block.
SCHEMA_TRANS_MEMORYMinimum is 2 MB; can be overallocated to use any remaining available memory.

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