.. _browseresults:

Hands-On Exercise 8: browse published results
#############################################

In this exercise, we will run again the workflow of the exercise :doc:`a multi-node workflow <06_multinode>`,  
then we will browse its results through the Oozie Web Console that was previously introduced.   

Prerequisites
=============

* You have cloned the Hands-On git repository (see :ref:`hands-on-repo`),
* *(Only for python)* You have installed the required software (see :ref:`python-reqs`).

Install the Hands-On
====================

* Install the Hands-On Exercise 8, just type:

.. code-block:: console

  cd
  cd dcs-hands-on
  mvn clean install -D hands.on=8 -P bash


Run the workflow 
================

* Type the following command:

.. code-block:: console

  ciop-run

* Wait until the workflow is completed (it will take approximately five minutes).

Browse the results
==================

* Open a browser and type http://$HOSTNAME:50070 ,

.. tip::
     
  Read how to obtain the value of your Sandbox $HOSTNAME in the :doc:`General Notes <general_notes>` section

* Click on the link *Browse the filesystem*,

* Click on the link *ciop*,

* Click on the link *run*,

* Click on the link *hands-on-8*,

* Click on the link representing the workflow id (e.g., *0000269-150209145053100-oozie-oozi-W*),

* Click on the link *_result*,
  
* To see intermediate results, click on *node_expression* and then click on *data*. 

The following images show the steps that we have just performed:

.. figure:: includes/browseresults/gui1.png
   :scale: 80 %
   :alt: Browse results

.. figure:: includes/browseresults/gui2.png
   :scale: 80 %
   :alt: Browse results

.. figure:: includes/browseresults/gui3.png
   :scale: 80 %
   :alt: Browse results

.. figure:: includes/browseresults/gui4.png
   :scale: 80 %
   :alt: Browse results

.. figure:: includes/browseresults/gui5.png
   :scale: 80 %
   :alt: Browse results

.. figure:: includes/browseresults/gui6.png
   :scale: 80 %
   :alt: Browse results

.. figure:: includes/browseresults/gui7.png
   :scale: 80 %
   :alt: Browse results


Access the results from a shell
===============================

You can also access the results from a shell or from scripts. Since the results are on the HDFS file system, you have to use the ``hadoop`` command with its subcommand ``fs``.

For example, to see the results from the example above, you would have to use the following command:

.. code-block:: console

   hadoop fs -ls /ciop/run/hands-on-8/0000269-150209145053100/_results
   
You can use other shell-like subcommands to access, manipulate and transfer files. For a full guide of HDFS commands, see the official documentation on the `Apache web site <https://hadoop.apache.org/docs/r2.7.1/hadoop-project-dist/hadoop-common/FileSystemShell.html>`_.

   
Recap
=====

#. We executed a multinode workflow; 
#. We browsed either final or intermediate results through the Oozie Web Console.