Department of Computer Science at UH

University of Houston

Department of Computer Science

In Partial Fulfillment of the Requirements for the Degree of
Doctor of Philosophy

Mohamad Chaarawi

Will defend his dissertation

Optimizing Peformance of Parallel I/O Operations for High Performance Computing


I/O is probably the most limiting factor on high-end machines for large scale parallel applications as of today. Parallel I/O offers interfaces to allow multiple processes to access the same file concurrently. MPI, the {\it de-facto} standard for message passing in parallel scientific applications, has a parallel I/O specification defined in version two of the standard. Some of the features that distinguish MPI-I/O from POSIX I/O include relaxed consistency semantics, file views, collective I/O operations, and shared file pointers. As of today, when it comes to meeting the needs of the HPC community, existing MPI-I/O libraries are limited in terms of performance, modularity, and portability over different hardware architectures and file systems. In this thesis the following goals are accomplished: develop a novel and flexible architecture for a parallel I/O library, develop new algorithms for collective I/O operations, develop automatic selection algorithms for choosing an optimal or close to optimal collective I/O algorithms and its associated parameters such as the number of aggregators (the processes that actually handle the low-level I/O operations), and finally develop a static, pre-execution tuning methodology to tune for runtime parameters/algorithms that are ideal for a certain scenario.

Date: Tuesday, March 29, 2011
Time: 09:30 AM
Place: 550-PGH
Faculty, students, and the general public are invited.
Advisor: Dr. Edgar Gabriel