[MPICH] Profiling an application's network usage through MPI calls

[William Gropp]

At 01:42 PM 9/4/2005, Diego M. Vadell wrote:
>Hi,
>    First of all, sorry if this is has a known answer, is a stupid 
> question, or
>if Im out of place somehow. As I'm new to mpi and MPICH, I know I may have
>wrong concepts.
>    I co-administer a couple of clusters in the university of Buenos Aires. I
>would like to know how does the MPI applications use the network: for
>example, lots of short messages, some big messages, lots of big messages,
>etc.
>     My first thought was to use tcpdump and then process it's output. Then I
>thought that if there were a log file where mpich left a timestamp and the
>size of the MPI message each time it sends one, I would have more accurate
>information.
>
>   My questions: is there any way to make MPICH leave such a log? also, is
>there a better way to profile an application's network usage?

One other tool that you might try is fpmpi (www.mcs.anl.gov/fpmpi ).  This 
is a summary tool that creates a text file during MPI_Finalize that 
summarizes the communication that took place during the run.  There are 
other, similar tools as well.  These tools all rely on the profiling (PMPI) 
interface, so you can easily customize them to your needs and they work 
with any MPI implementation.

Bill


>Thanks in advance,
>  -- Diego.

William Gropp
http://www.mcs.anl.gov/~gropp