Current OpenMPI Resource Manager
The current OpenMPI resource manager sends commands and reads responses directly to the remote host via an ssh connection. When the resource manager first starts, it runs the "ompi_info" command to determine the version of OpenMPI installed, and to obtain a list of MCA parameters. The OpenMPI version is used to select different parsers to handle the differences in command output between the versions.
The launch configuration resources tab supports a basic and advanced tab. In the basic tab, the individual settings are specified via controls. These controls are used to construct a series of command line options that are passed to the "mpirun" command when a job is launched. In the advanced tab, the current command line options (determined by the settings in the basic tab) are displayed in a text field. The user has the choice of overriding the options by editing the text field. In addition, the MCA parameters obtained at startup are displayed in a scrollable table. Users can change their default values and select individual parameters. These are then added to the command line prefixed with a "-mca" option.
Considerations for new Implementation
In addition to providing statically defined options to be displayed in the launch configuration panels, the new implementation must also support the dynamic discovery of parameters that can then be displayed in an editable table. In addition, it is also necessary to dynamically obtain version information so that correct functionality can be selected at runtime.
This image shows the advanced tab with the command line options that will be passed to the "mpirun" command. An MCA parameter has also been selected and the default value changed to "45".