Man Linux: Main Page and Category List


       LAM SSI - introduction to LAM System Services Interface (SSI)


       The  SSI  in  LAM/MPI  is  used to select one (or more) system services
       interfaces at run-time.


       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

       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).


       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

           Send the verbose output to the syslog.

           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).

           Use the ID <id> for the syslog prefix.

           Send the verbose output to stdout.

           Send the verbose output to stderr.

           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.

           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.

           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.


       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


       lamssi_boot(7), lamssi_coll(7), lamssi_cr(7), lamssi_rpi(7), mpirun(1),
       lamboot(1), recon(1), lamwipe(1), LAM User's Guide