Doc/add troubleshooting (#109)

Author: cbellot000

docs/source/getting_started/index.rst

@@ -1,3 +1,5 @@
+.. _ref_getting_started:
+
 ===============
 Getting Started
 ===============

docs/source/user_guide/index.rst

@@ -24,3 +24,4 @@ Additionally, :ref:`user_guide_plotting` describes how to plot results via PyVis
    operators
    fields_container
    plotting
+   troubleshooting

docs/source/user_guide/troubleshooting.rst

@@ -0,0 +1,60 @@
+.. _user_guide_troubleshooting:
+
+===============
+Troubleshooting
+===============
+This section explains how to resolve the most common issues encountered with ``pydpf-core``.
+It also includes suggestions for improving scripts.
+
+Using the Server
+----------------
+
+Starting DPF Server
+~~~~~~~~~~~~~~~~~~~
+While using the DPF-Python API to start the server with :py:meth:`start_local_server()
+<ansys.dpf.core.server.start_local_server>` or while starting the server manually (with ``Ans.Dpf.Grpc.sh``
+or ``Ans.Dpf.Grpc.bat``), a Python error might occur: "TimeoutError: Server did not start in 10 seconds".
+This kind of error might mean that the server or its dependencies were not found. Ensure that
+the environment variable ``AWP_ROOT{VER}`` is set, where VER=212, 221, ....
+
+Connecting to DPF Server
+~~~~~~~~~~~~~~~~~~~~~~~~
+If an issue appears while using the pydpf-core API to connect to an initialized server with :py:meth:`connect_to_server()
+<ansys.dpf.core.server.connect_to_server>`, ensure that the IP address and port number that are set as parameters
+are applicable for a DPF server started on the network.
+
+Importing pydpf-core module
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Assume that you are importing the pydpf-core module:
+
+.. code-block:: default
+
+    from ansys.dpf import core as dpf
+
+If an error lists missing modules, see the compatibility paragraph of :ref:`_ref_getting_started`.
+The module `ansys.grpc.dpf <https://pypi.org/project/ansys-grpc-dpf/>`_ should always be synchronized with its server
+version.
+
+
+Performance Issues
+------------------
+
+Getting and Setting a Field's Data
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Accessing or modifying field data :py:class:`Field<ansys.dpf.core.field.Field>` entity by entity can
+be slow if the field's size is large or if the server is far from the Python client. To improve performance,
+use :py:meth:`as_local_field()<ansys.dpf.core.field.Field.as_local_field>` in a context manager.
+An example can be found in :ref:`_ref_use_local_data_example`.
+
+Slow Autocompletion in Notebooks
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Autocompletion in Jupyter notebook can sometimes be slow for large models. The interpreter might
+evaluate getters of some properties when the tab key is pressed. To disable this capability use
+:py:meth:`disable_interpreter_properties_evaluation()<ansys.dpf.core.settings.disable_interpreter_properties_evaluation>`:
+
+.. code-block:: default
+
+    from ansys.dpf import core as dpf
+    dpf.settings.disable_interpreter_properties_evaluation()
+
+