Newsgroups: comp.parallel.mpi
From: gdburns@osc.edu (Greg Burns)
Subject: LAM 5.2 is now available.
Organization: Ohio Supercomputer Center
Date: 24 Aug 1994 12:46:25 -0400
Message-ID: <33fth1$a5r@tbag.osc.edu>


Ohio Supercomputer Center (OSC) announces the general release of
LAM 5.2, a UNIX cluster implementation of the MPI interprocess communication
standard.  The software is available in source code form under the terms
of the GNU general license (V2).  Distribution is via anonymous ftp from
tbag.osc.edu under pub/lam.

It is not absolutely necessary to upgrade
to LAM 5.2 unless you want a) a performance boost or b) to use XMPI.
Of course, it contains all the 5.1 patches plus a few fixes that were
deemed too trivial for patches.  Look at Misc/Fixes5.1 in the new
release for a somewhat cryptic record of all the changes.  The
more significant changes are listed in the Release Notes below.

XMPI will follow in about a week.  You will absolutely need 5.2 to run it.

--
Trollius Group, OSC

-=-

Release Notes for Ohio LAM 5.2

This release features a new kernel, a major change but mostly invisible
to the user, except in performance.  The new kernel does not 
enforce a single process, pre-emptive scheduling policy.  All ready
processes are allowed to run and be scheduled by the native operating
system.  This new kernel is also simpler and therefore signficantly faster.

The datalink protocol is completely independent of LAM synchronization.
ACKs are no longer sent as LAM messages.  This is the other major
cause for performance improvement.

A new supported machine is added, the HP 9000/755 running HP-UX 9.01.
Other modern variations of HP 9000 machines probably also work.
There is code for SCO in this release, but it is not officially supported.

The MPI implemenatation is upgraded according to the Errata Sheet for
MPI Specification, 7/12/94.

The output of mpitask is formatted differently.  See mpitask(1).

The F77 ARCV() function now takes a user supplied function name, like
its C counterpart.

-=-

LAM Technical Summary

LAM is a UNIX cluster implementation of the MPI interprocess communication
standard.  The factory default software supports the following platforms:

Sun 4 (sparc), SunOS 4.1.3
Sun 4 (sparc), Solaris 2.3
SGI IRIX 4.0.5
IBM RS/6000, AIX v3r2
DEC AXP, OSF/1 V1.3
HP 9000/755, HP-UX 9.01

Key Features

- standard MPI communication
- heterogeneous networks
- micro-kernel, multi-process, modular structure
- hands-on monitoring and control
- PVM compatibility
- parallel I/O

Standard MPI Interprocess Communication

LAM is a non-proprietary platform for developing and executing
MPI applications.  LAM is a full cluster computing environment.  MPI does
not specify file I/O, machine configuration and process management,
so LAM fills in these gaps to form a complete system.

LAM has debugging commands to examine the MPI synchronization
status of processes and messages.

LAM fully implements the final draft of
the MPI standard, version 1.0.

PVM Compatibility

LAM also has a library to run PVM 3 applications.  As with
MPI, there are debugging commands to examine the PVM synchronization
status of processes and messages.

Configuration and Process Management

LAM unpacks and installs anywhere.  The user shell's search path
is used to locate the LAM server, utilities and application programs
on every machine.  Configuring a cluster is listing machine names
in a file and invoking a utility.

Process management is completely dynamic.  The user or any process
situated at any machine can run a program residing in any second
machine on any third machine.  NFS is not required.  The user or
any process can kill any other process.

An executable may reside in the target node's file space or LAM can
transfer the file from a third node.

I/O

When NFS or friends are not readily available, LAM has a set of
functions that mirror the POSIX functions and provide remote
access to the filesystem of other machines.  Special parallel
file modes arbitrate and order multiple client I/O operations.

User Interface

LAM's UI is just your usual shell.  There is no special environment,
only a set of utility programs.

Documentation

There are user guides for C and Fortran programmers as well as
a complete set of manual pages covering every function and command program.

Visit the LAM/MPI WWW pages at http://www.osc.edu/lam.html

-=-

LAM is a subset of Trollius, an environment for UNIX clusters + MPP.
Trollius was originally developed at the Cornell Theory Center.
Trollius is a trademark of The Ohio State University and the Cornell
Research Foundation.

LAM development was sponsored by OSC, OSU, Cray Research Inc., and
Alex Informatique.

