fi_mon_sampler(1)              Libfabric v2.2.0              fi_mon_sampler(1)

NAME
       fi_mon_sampler - Simple sampler for ofi_hook_monitor provider.

SYNOPSIS

               fi_mon_sampler [OPTIONS] <target>      sample from file(s) at <target>


DESCRIPTION
       Extract data from the ofi_hook_monitor provider via communication
       files.  <target> can either be one communication file or a folder of
       files.  Data is exported based on -f <format> and either printed to
       stdout (only for single files), or stored per communication file at -o
       <outpath>.  The sampler can watch the communication files for changes
       via the option -w <msec> for repeated sampling.

       The name format of the output files is based on the ofi_hook_monitor
       provider and is as follows: <ppid>_<pid>_<sequential id>_<job
       id>_<provider name>.  ppid and pid are taken from the perspective of
       the monitored application.  In a batched environment running SLURM, job
       id is set to the SLURM job ID, otherwise it is set to 0.

HOW TO RUN
       Launch a libfabric application with FI_HOOK=monitor to enable the
       ofi_hook_monitor provider.  Adjust the monitor provider settings
       according to fi_hook(7).

       Then launch the sampler via fi_mon_sampler -o <output> <target>.  By
       default, the ofi_hook_monitor provider stores data at
       /dev/shm/ofi/<uid>/<hostname>.

       The sampler will generate output files in the directory specified at
       <output>, one for each monitored provider.

OPTIONS
       -w <msec>
              Watch files for changes, check every <msec> milliseconds.

       -f <format>
              Output format.  Currently only supports CSV.

       -o <outpath>
              Output file path.  Uses stdout if unset.

USAGE EXAMPLES
       Launch a libfabric application and enable the ofi_hook_monitor
       provider:


              FI_HOOK=monitor fi_pingpong [OPTIONS]


       Launch another fi_pingpong with the respective settings.

       Finally, launch the sampler:


              fi_mon_sampler -o $HOME -w 1000 -f csv /dev/shm/ofi/$UID/$HOSTNAME


OUTPUT
       Output files will be generated in the folder specified at -o <output>.

       In -f csv mode, this will contain a CSV file with data for all
       monitored libfabric functions.  For each function, both the count and
       sum counters are exported, indicated by the column name suffix _c and
       _s respectively.  In addition, each function is monitored for each data
       size bucket.  Refer to fi_hook(7) for more details.

       Example CSV output, first four columns, first three rows:


              mon_recv_0_64_c,mon_recv_0_64_s,mon_recv_64_512_c,mon_recv_64_512_s
              0,0,0,0
              22529,0,0,0
              113664,0,0,0


SEE ALSO
       fi_hook(7)

AUTHORS
       OpenFabrics.

Libfabric Programmer's Manual     2025-06-06                 fi_mon_sampler(1)