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## 23.3.3.13 Data Node Memory Management 

All memory allocation for a data node is performed when the node is started. This ensures that the data node can run in a stable manner without using swap memory, so that NDB  can be used for latency- sensitive (realtime) applications. The following types of memory are allocated on data node startup: 

•Data memory 

•Shared global memory 

•Redo log buffers 

•Job buffers 

•Send buffers 

•Page cache for disk data records 

•Schema transaction memory 

•Transaction memory 

•Undo log buffer 

•Query memory 

•Block objects 

•Schema memory 

•Block data structures 

•Long signal memory 

•Shared memory communication buffers 

The NDB  memory manager, which regulates most data node memory, handles the following memory resources: 

•Data Memory ( DataMemory ) 

•Redo log buffers ( RedoBuffer ) 

•Job buffers 

•Send buffers ( SendBufferMemory , TotalSendBufferMemory , ExtraSendBufferMemory , ReservedSendBufferMemory ) 

