Documentation

Troubleshooting

A list of frequently asked questions is under construction: FAQ.

General Overview

P2P-MPI has two main roles:

1. Middleware: it is in charge of building an execution platform by discovering particpating modes.
2. Programming model:it provides a message-passing programming model, through an MPI-like API.

Middleware: starting a P2P-MPI node

Documentation related to the middleware part is divided into the following sections:

• Installation instructions: how to install and run P2P-MPI.
  • Linux Installation instructions
  • Windows Installation instructions
• Quick commands guide: how to start, stop, monitor P2P-MPI nodes.
• Visualisation: how to use the monitoring tool.
• Job submission scenario: explains what steps follow a job submission and what's the middleware work.

A small Flash demo illustrates a typical session.

Programming: writing programs to run on P2P-MPI nodes

Documentation concerning the programming model and the API is:

• Prototypes of available functions in current implementation of P2P-MPI: API documentation
• The specification P2P-MPI partially covers (see section Links): MPJ specification
• Examples: Samples programs

Compiling and running programs

• Compilation is as simple as javac myprogram.java.
• Running a program implies to transfer at least the .class file and optionally input files.

  • A shorthand is provided when you run a class file alone (e.g. myprogram.class):

    p2pmpirun -n 3 myprogram
    In that case, the MPD searches for a myprogram.class in the current directory, and if found will transparently transfer it to requested peers.

  • In a general way, you should use the -l option to specify a file in which are listed (one per line) the files to transfer.

    p2pmpirun -n 3 -l mylist myprogram
    where mylist is for example:
    /home/john/examples/myprogram.class /home/john/examples/myinput.dat http://mywebserver.org/~john/myinput2.dat
    Note that
    • files should be specified with their absolute path,
    • the class file must be in the list (whatever its place),
    • http:// URL can be used instead of files.