The MPI I/O extension to the Pablo Trace Library is a set of programs that can be substituted for standard MPI I/O calls so that I/O performance data can be captured and measured. These programs perform exactly the same routines as their standard MPI I/O counterparts, but they have been augmented by instrumentation software, attached before and after the call itself, to capture internal data. Programmers compile their instrumented source code and link it with the trace library. During program execution, perfomance data captured by the instrumentation is recorded in SDDF files. Analysts use Pablo analysis tools to study these SDDF files and understand how MPI I/O behaves and interacts with other system components. End-to-end examples of each of the following codes are included:
Runtime Tracing of a C Application Real-time Tracing of a FORTRAN Application