Gather-arrange-scatter: Node-level request reordering for parallel file systems on multi-core clusters

Multiple processors or multi-core CPUs are now in common, and the number of processes running concurrently is increasing in a cluster. Each process issues contiguous I/O requests individually, but they can be interrupted by the requests of other processes if all the processes enter the I/O phase together. Then, I/O nodes handle these requests as non-contiguous. This increases the disk seek time, and causes performance degradation.