Patent ID: 7487393

Claim:
A computer implemented method for checkpointing a massively parallel computer system comprising the steps of: a) a checkpoint server broadcasting a list of data block checksums from a previous checkpoint to all compute nodes arranged in a cluster; and b) each compute node searching its own memory image for checksum matches using an rsync protocol rolling checksum algorithm; wherein each node performs the steps of: 1) producing a template of new data blocks with checksums that didn't exist in the previous checkpoint; 2) producing a template of references to the original data blocks that did exist in the previous checkpoint; 3) sending its new data block checksum template to an adjacent node in the cluster of nodes; 4) comparing checksums to find common data blocks between all adjacent nodes as well as its own data blocks; 5) informing adjacent nodes to replace a reference to a common data block with a reference to a data block on another node; c) the checkpoint server then collecting reference templates from the compute nodes and storing them in the checkpoint server; and d) collecting new unique data blocks and storing them to the checkpoint server.