lamssi(7) | LAM SSI OVERVIEW | lamssi(7) |
lamssi - 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 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).
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:
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):
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.
lamssi_boot(7), lamssi_coll(7), lamssi_cr(7), lamssi_rpi(7), mpirun(1), lamboot(1), recon(1), lamwipe(1), LAM User's Guide
July, 2007 | LAM 7.1.4 |