lamssi(7)
NAME
lamssi - introduction to LAM System Services Interface (SSI)
DESCRIPTION
The SSI in LAM/MPI is used to select one (or more) system services interfaces at run-time.
OVERVIEW
LAM SSI instances are uniquely described in terms of "kinds" (also referred to as "types") and "modules". The "kind" refers to which set of system services the SSI instance will apply to. For example, LAM currently has several kinds: "boot", "coll", "cr" and "rpi". The "module" refers to a specific SSI instance of a given kind. Each kind has o boot modules are used to start the LAM run-time environment (i.e., they provide the back-end functionality to lamboot(1)). boot modules are discussed further in the lamssi_boot(7) man page. coll modules provide back-end algorithms and functionality for the MPI collective communications. coll modules are described in lamssi_coll(7). cr modules provide checkpoint/restart functionality for MPI jobs. See lamssi_cr(7) for details. rpi modules provide back-end functionality for MPI point-to-point communications. rpi modules are detailed in lamssi_rpi(7).
VERBOSE OPERATION
The user can force SSI modules to be verbose by setting the
LAM_SSI_ssi_verbose environment variable before invoking mpirun, or by
using the -ssi command line switch to mpirun. For example:
mpirun -ssi ssi_verbose 1 C foo
Tell the SSI modules to be verbose, and default to sending their
output to stderr.
The ssi_verbose kind is a "pseudo-kind" in that it is used to pass
parameters to the main SSI meta-glue itself -- not to any particular
kind. It can take many different parameters to format where and how
the verbose output will be sent (note that at least one parameter must
be specified, even if it is an invalid parameter). Any combination of
the following parameters may follow the ssi_verbose kind (separated by
commas):
syslog
Send the verbose output to the syslog.
syslogpri:<priority>
Set the syslog output priority to <priority>. Using this paramter
implies the syslog parameter. The default priority is info
(LOG_INFO). Valid <priority> values are: notice (LOG_NOTICE),
info, and debug (LOG_DEBUG).
syslogid:<id>
Use the ID <id> for the syslog prefix.
stdout
Send the verbose output to stdout.
stderr
Send the verbose output to stderr.
file[:<filename>]
Send the verbose output to a file in the LAM per-user, per-node
meta information directory (usually located in /tmp). If
<filename> is specified, send the output to the file named
lam-<filename>. If <filename> is not specified, send the output to
the file named lam-ssi.txt.
fileappend
Append to the file when sending the verbose output (create the file
if it does not exist). If this parameter is not given, if the file
already exists, it will be overwritten. Using this parameter
implies the file parameter.
level:vlevel
Indicate the specific verbosity level to be used. Although the
specific meaning of the verbosity level is left up to individual
SSI modules, generally negative numbers mean no verbose messages, 0
means a minimal set of messages, and positive numbers mean more
messages (the greater the positive number, the more output messages
will be generated). If left unspecified any any other ssi_verbose
parameters are specified, the default level of 0 is used.
If multiple parameters are passed in ssi_verbose, the output will be
directed as implied by all the parameters. If no valid parameters are
passed (e.g., a single invalid parameter is passed), then output will
be directed to stderr by default.
Also note that as with all SSI parameters, all of these values may be
passed by setting the environment variable LAM_SSI_ssi_verbose before
invoking mpirun. However, parameters passed through "-ssi ssi_verbose"
will take precedence over environment variables.
EXAMPLES
mpirun -ssi ssi_verbose 1 C foo
Since no valid parameters were passed, the verbose output will be
sent to stderr.
mpirun -ssi ssi_verbose file:output.txt,syslogpri:notice C foo
Send the verbose output to both the file lam-output.txt in the LAM
user meta directory as well as to the syslog with a priority of
LOG_NOTICE.
SEE ALSO
lamssi_boot(7), lamssi_coll(7), lamssi_cr(7), lamssi_rpi(7), mpirun(1), lamboot(1), recon(1), lamwipe(1), LAM User's Guide
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
