1. A method for minimally buffered data transfers between nodes in a data communications network, the method comprising: receiving, by an origin messaging module on an origin node from an application on the origin node, a storage identifier, a complex origin data type, and a complex target data type, the storage identifier specifying origin application storage containing data on the origin node, the complex origin data type describing a subset of the data contained in the origin application storage, the complex target data type describing an arrangement of the subset of the data in target application storage on a target node; creating, by the origin messaging module, origin metadata describing the complex origin data type; selecting, by the origin messaging module from the origin application storage in dependence upon the origin metadata and the storage identifier, the subset of the data for transmission to the target node; and transmitting, by the origin messaging module to a target messaging module on the target node, the selected subset of the data for storing in the target application storage in dependence upon the complex target data type without buffering the subset of the data in a temporary buffer on the target node.