.. _uguide_change_target:


***********************
Changing Target Machine
***********************

All of our examples so far have been run locally. Its time to run something on a
HPC! One of the features of Ensemble Toolkit is that you can submit tasks on
another machine remotely from your local machine. But this has some
requirements, you need to have passwordless ssh access to the target machine. If
you don't have such access, we discuss the setup :ref:`here <ssh_gsissh_setup>`.
You also need to confirm that RP and Ensemble Toolkit are supported on this
machine. A list of supported machines and how to get support for new machines is
discussed :ref:`here <entk>`.

.. note:: The reader is assumed to be familiar with the :ref:`PST Model <app_model>` and to have read through
            the :ref:`introduction` of Ensemble Toolkit.

.. note:: This chapter assumes that you have successfully installed Ensemble Toolkit, if not see :ref:`Installation`.


Once you have passwordless access to another machine, switching from one target
machine to another is quite simple. We simply re-describe the resource
dictionary that is used to create the Resource Manager. For example, in order to
run on the ACCESS Stampede cluster, we describe the resource dictionary as
follows:

.. literalinclude:: ../../../examples/user_guide/change_target.py
    :language: python
    :lines: 63-71
    :dedent: 4


You can download the complete code discussed in this section :download:`here
<../../../examples/user_guide/change_target.py>` or find it in your virtualenv under
``share/radical.entk/user_guide/scripts``.


.. code-block:: bash

    python change_target.py


Let's take a look at the complete code in the example. You can generate a more verbose output by setting the environment
variable ``RADICAL_ENTK_VERBOSE=DEBUG``.

A look at the complete code in this section:

.. literalinclude:: ../../../examples/user_guide/change_target.py