NAME

       lat_rpc - measure interprocess communication latency via Sun RPC

SYNOPSIS

       lat_rpc -s
       lat_rpc [ -P <parallelism> ] [ -W <warmups> ] [ -N <repetitions> ] [ -p tcp|udp ] hostname
       [ udp|tcp ]
       lat_rpc -S hostname

DESCRIPTION

       lat_rpc is a client/server program that  measures  interprocess  communication  latencies.
       The  benchmark  passes  a  token  back  and  forth between the two processes (this sort of
       benchmark is frequently referred to as a ``hot potato'' benchmark).  No other work is done
       in the processes.

       This  benchmark  may  be  compared  to  the  TCP  and  UDP  forms of the same benchmark to
       accurately see the cost of using RPC versus the  cost  of  using  plain  old  TCP  or  UDP
       sockets.   It  is  worth noting that the RPC form is passing back and forth a single byte,
       not some long complicated record.

       lat_rpc has three forms of usage: as a server (-s), as a client (lat_rpc  localhost),  and
       as a shutdown (lat_rpc -S localhost).

       The  client  form may specify the protocol over which the RPCs are performed.  The default
       is to measure performance for both udp and tcp.

OUTPUT

       The reported time is in microseconds per round trip and includes the total time, i.e., the
       context switching overhead is includeded.  Output format is like so

       RPC/udp latency using localhost: 1344 microseconds
       RPC/tcp latency using localhost: 2089 microseconds

ACKNOWLEDGEMENT

       Funding  for  the  development  of  this  tool  was  provided by Sun Microsystems Computer
       Corporation.

SEE ALSO

       lmbench(8).

AUTHOR

       Carl Staelin and Larry McVoy

       Comments, suggestions, and bug reports are always welcome.

(c)1994 Larry McVoy                           $Date$                                   LAT_RPC(8)