Abstract: A distributed network is described which contains a plurality of interconnected nodes each node including a processor and data storage apparatus. A plurality of key-index data identifiers are distributed among the nodes, with each node including a tree data structure in non-volatile storage defining locations of the key-index data identifiers. The tree data structure includes a ROOT data structure comprising two lists, "NEW ROOT" and "OLD ROOT", each comprised of an ordered array of boundaries assigned nodes for the top level of the tree. A method is described for balancing the tree data structure which comprises the steps of:a. a providing in each of the nodes across which the key-index data identifiers are distributed, at least copies of the two lists, "NEW ROOT" and "OLD ROOT", of the ROOT data structure;b. determining when a first node contains an excess of key-index data identifiers;c. moving the excess of key-index data identifiers to a second node;d.

Abstract: A data processing system includes both volatile and nonvolatile memories, user-inaccessible file control software and performs a method for recovering from a malfunction occurring during a file transaction that prevents accomplished microscopic transactions from being lost.

Abstract: This is method for parity protecting distributed data files in a multi-node, parallel data processing network, with each node having a data store. Each data file is organized as a series of fixed size file data blocks, each file data block being comprised of a block identifier and a plurality of data bit positions. The method comprises: distributing at least N-1 file data blocks across N-1 nodes, each of the N-1 file data blocks being stored in a data store at an available physical location, which physical location may be selected from any within an area of the data store reserved for file data blocks, each data store having an associated directory indicating where each file data block is located; exclusive OR'ing data bits in corresponding bit positions in each of the N-1 file data blocks; and storing the Exclusive OR results in corresponding bit positions of a parity file data block in a data store in node N.