ParaStation MPI is capable of starting serial tasks, therefore tasks not parallelized with MPI, within the cluster. All actions described in section the section called “Placing processes onto nodes”, the section called “Redirecting standard input and output” and the section called “Spawning the environment” are also considered for this type of tasks.
In order to start the serial program program
$ mpiexec -np 1program[args]
where args are the arguments that shall be
passed to program.
Depending on the settings of the environment variables as
discussed in the previous sections,
program will be started on a
distinct node of the cluster. Parts of the current environment
will eventually be passed to this node, too. Also the input and
output is forwarded correctly to and from the remotely started
process.
Starting serial processes using the ParaStation MPI management facilities offers a couple of advantages:
Load balancing performed by ParaStation MPI towards serial processes results in a much better usage of the whole cluster in contrast of distributing the jobs manually.
The user does not have to deal with the question, which node should be used for a particular job. ParaStation MPI takes care about deciding where (and when) to run the task.
The possibility of starting serial jobs from the frontend machine without having to log on to the node that actually runs the jobs enables the system operator to disallow the users to log on the nodes in general. This enables much better control over the cluster and increases the security of the system.