These examples are based on
``http://www.mpi-forum.org/docs/mpi-20-html/node106.htm''

1. Simple Client-Server Example (one client and one server)

   Run in two terminals separately. In terminal 1, run server as

     > mpiexec -np 1 Rscript simple.server.r

   and this prints a port name randomly to STDOUT and hand, such as

   Port name:
   1247084544.0;tcp://10.0.2.15:51581+1247084545.0;tcp://10.0.2.15:39522:300

   then the terminal 1 will hang and wait response from a client.
   In terminal 2, run client with the random port name as

     > mpiexec -np 1 Rscript simple.client.r \
'1247084544.0;tcp://10.0.2.15:51581+1247084545.0;tcp://10.0.2.15:39522:300'


2. Named Client-Server Example (one client and one server)

     > # ompi-server -d --report-uri urifile &
     > mpiexec --report-uri urifile -np 1 Rscript named.server.r &
     > mpiexec --ompi-server file:urifile -np 1 Rscript named.client.r
     > rm -f urifile
