lsplace - display the current best host(s) to execute one or more tasks
lsplace [ -h ] [ -V ] [ -L ] [ -R res_req ] [ -n needed ] [ -w wanted ] [ host_name ... ]
Display the best host(s) for the execution of tasks. The host names displayed are separated by spaces. If one or more host_names are specified, only the specified hosts are used as candidates for the host selection. The returned hosts will have their load temporarily increased to avoid sending too many jobs to the same host in quick succession. The inflated load will decay slowly over time before the real load produced by the dispatched task is reflected in the LIM's load information.
-R res_req
Resource requirements. See lsfintro(1)
for a description of how a
resource requirement string is constructed. The selection section of
the resource requirement string is used to specify which hosts will be
selected. These hosts are then ordered according to the indices given
in the order section. The resource usage section is used to determine
how many tasks can be placed on a given host and how the load should
be adjusted. If this option is not specified, then the default
resource requirement is assumed: CPU and memory intensive, needing the
same type of hosts as the local host.
-h Print command usage to stderr and exit.
-V Print LSF release version to stderr and exit.
-n needed
The number of CPUs that are minimally required. At least one or more
needed host names must be returned on success. The names of the best
host(s) are printed to the stdout. Host names may be duplicated for
multiprocessor hosts, to indicate that multiple tasks can be placed on
a single host. The default value is one. Each task needs the
resources specified by res_req. If needed is 0, it means as many CPUs
as possible. lsplace will print « Not enough host(s) currently eligible
« and exit with status 1 if the required number of hosts holding
the required resources cannot be found.
-w wanted
The number of CPUs desired. Up to wanted host names will be printed on
success. Host names may be duplicated for multiprocessor hosts, to
indicate that multiple tasks may be placed on a single host. The
default value is one. If wanted is 0, it means as many CPUs as possible.
-w and -n can be combined to specify the upper and lower bounds
in processors to be returned, respectively. For example, the command
lsplace -n3 -w5 return at least three and at most five host names.
-L Attempt to place tasks on as few hosts as possible. This is useful for distributed parallel applications in order to minimize communication costs between tasks.
lsplace is mostly used in backquotes to pick out a host name which is then passed to other commands.
For example:
% lsrun -m `lsplace -R hppa` task
ask lsplace to find a lightly loaded HPPA-RISC host for task to run
on.
lsplace return 1 if insufficient hosts are available. The exit status is -10 if a problem is detected in LSF, -1 for other errors, otherwise 0.
lsinfo(1) , ls_placereq(3) , lsload(1) , lsrun(1)