Why Master/Worker?


More Information

A quick example implementing manager and workers can be found at the page LAM/MPI/Rmpi in the R_note web site. This page will describe the manager and workers computing in Rmpi. The manager and workers computing is a style of "Multiple Instruction Multiple Data" (MIMD) in parallel programming, while it can be written in the Single Program Multiple Data (SPMD) style where the manager is one of the workers.


Rmpi

By default, Rmpi runs as the "manager and workers" framework in an interaction mode of R. This makes debugging extremely difficult. However, it is possible to run as the "workers" framework in an interaction mode of R. In MPI computing, the "workers" framework simplifies communications different than the "manager" and "workers" framework. In general, the "workers" framework make a perfect computing environment in a command mode of R, as well as Single Program Multiple Data (SPMD).

LAM/MPI, MPICH, MPICH2 or OpenMPI is a MPI system requirement for the R package Rmpi. The LAM/MPI is recommended for Unix-based system, but is not available on Windows system. The MPICH2 is recommended for Windows system. The OpenMPI needs some instructions to execute in the Master/Worker style in an interactive mode of R. All the MPI systems are supposed to execute smoothly in the Single Program Multiple Data (SPMD) style in a command mode of R through Rscript.

Some starting examples (Master/Worker) can be found in

  1. Section "LAM/MPI/Rmpi" of R_note
  2. Rmpi Tutorial
  3. Rmpi for R

More useful implementations can be found in the Cookbook.