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A brief introduction to LAM / MPI parallel computing





* LAM / MPI Parallel Computing

LAM (Local Area Multicomputer) is an MPI programming environment and development system for heterogeneous computers on a network. With LAM, a dedicated cluster or an existing network computing infrastructure can act as one parallel computer solving one problem.

LAM features extensive debugging support in the application development cycle and peak performance for production applications. LAM features a full implementation of the MPI communication standard.

LAM Key Features

LAM is portable to all UNIX machines and includes standard support for SUN (SunOS and Solaris), SGI IRIX, IBM AIX, DEC OSF/1, HPUX, and LINUX.

More LAM Information

Message Passing Interface Standard

A multilateral gathering of parallel computing users, vendors and researchers has specified a complete interface for message-based interprocess communication. The MPI standard means true portability for parallel programs. It defines the necessary infrastructure for third party software products and will enable a wider proliferation of parallel technology. The specific semantics of the communication interface, its perceived popular and future prospects, need no longer be a factor in choosing an environment or a vendor for developing parallel applications. Users and buyers can focus on other factors such as efficiency of implementation and related development tools.

A complete implementation of the MPI-1.1 specification is part of LAM.

MPI Key Features

More MPI Information

Quick Tutorials
Standard Document
  • The MPI standard and other documents are available for browsing or download at the MPI Forum.
Miscellaneous
Bibliography and Papers
Other MPI sites on WWW





Running MPI in our own department

Things that you need to do

Ready to boot your parallel machines

Compiling MPI Programs

Refer to "MPI: It's Easy to Get Started" to see a simple MPI program. Hcc (hf77) is a wrapper for the C (F77) compiler that links LAM libraries. The MPI library is explicitly linked. Here I provide a mpi code hello.c.
% hcc -o hello hello.c -lmpi

Executing MPI Programs

A MPI application is started by one invocation of the mpirun command. A SPMD application can be started on the mpirun command line.
% mpirun -w n0-3 /Your/full/directory/hello
From process: 0 out of 4, Hello World! 

From process: 1 out of 4, Hello World! 

From process: 2 out of 4, Hello World! 

From process: 3 out of 4, Hello World! 


You have seen a print out from 4 different nodes.

Congraduations!!

Cleaning LAM

All user processes and messages can be removed, without rebooting.
% lamclean -v
killing processes, done      
sweeping messages, done      
closing files, done      
sweeping traces, done

Terminating LAM

The wipe tool removes all traces of the LAM session on the network.
% wipe -v lamhosts
tkill n0 (140.117.35.37)...
tkill n1 (140.117.35.38)...
tkill n2 (140.117.35.39)...
tkill n3 (140.117.35.87)...

Now you have killed the LAM session on the network.



Acknowledgements

This page is mostly the same as the page created by
LAM / MPI Parallel Computing
Laboratory for Scientific Computing
University of Notre Dame
The LAM Team
A specical thanks to Jeff Squyres, he helped me a lot during the installation, also S.Y. Wang spent hours helping me to read through the installation guide.






Chieh-Sen Huang
Office: 2002-2

e-mail: huangcs@math.nsysu.edu.tw
URL: http://www.math.nsysu.edu.tw/u/huangcs

Created and maintained by Chieh-Sen Huang. Last update: Oct. 9, 1998.