I/O Analysis and Optimization for an AMR Cosmology Application

In this paper, we investigate the data access patterns and file I/O behaviors of a production cosmology application that uses the adaptive mesh refinement (AMR) technique for its domain decomposition. This application was originally developed using Hierarchical Data Format (HDF version 4) I/O library and since HDF4 does not provide parallel I/O facilities, the global file I/O operations were carried out by one of the allocated processors. When the number of processors becomes large, the I/O performance of this design degrades significantly due to the high communication cost and sequential file access. In this work, we present two additional I/O implementations, using MPI-IO and parallel HDF version 5, and analyze their impacts to the I/O performance for this typical AMR application. Based on the I/O patterns discovered in this application, we also discuss the interaction between user level parallel I/O operations and different parallel file systems and point out the advantages a...

• Type: Conference
• Year: 2002
• Where: CLUSTER
• Authors: Jianwei Li, Wei-keng Liao, Alok N. Choudhary, Valerie E. Taylor
• Keywords: CLUSTER 2002, Distributed And Parallel Computing, I/O Performance, Parallel I/o, file I/o