Minor fix doc and test

python/hsfs/feature_view.py

@@ -241,29 +241,19 @@ def init_serving(
 
         !!! example
             ```python
-            # get feature store instance
-            fs = ...
-
-            # get feature view instance
-            feature_view = fs.get_feature_view(...)
-
             # initialise feature view to retrieve a feature vector using the RonDB REST http client
             feature_view.init_serving(
                 training_dataset_version=1,
                 init_online_store_rest_client=True,
             )
             ```
 
-        Reset the Online Store REST Client connection to fix configuration options:
+        You can reset the Online Store REST Client connection to fix configuration options. In particular, if you have
+        called `get_feature_vector` or `get_feature_vectors` without first initialising the client, it results in a default configuration
+        being set for the rest client. This will reset the client and apply the new configuration options.
 
         !!! example
             ```python
-            # get feature store instance
-            fs = ...
-
-            # get feature view instance
-            feature_view = fs.get_feature_view(...)
-
             # reset the RonDB REST http client connection
             feature_view.init_serving(
                 training_dataset_version=1,
@@ -272,6 +262,21 @@ def init_serving(
             )
             ```
 
+        Note that both the SQL connector and the REST client can be initialised at the same time. This is useful if you want to
+        fallback on one connector if the other fails.
+
+        !!! example
+            ```python
+            # initialise feature view to retrieve a feature vector using both the SQL connector and the RonDB REST http client
+            feature_view.init_serving(
+                training_dataset_version=1,
+                init_online_store_sql_client=True,
+                init_online_store_rest_client=True,
+            )
+            # When initialising both clients, the SQL connector will be used by default. Change the default client using `set_default_online_client`.
+            feature_view.set_default_online_client("rest")
+            ```
+
         # Arguments
             training_dataset_version: int, optional. Default to be 1 for online feature store.
                 Transformation statistics are fetched from training dataset and applied to the feature vector.
@@ -282,15 +287,15 @@ def init_serving(
                 Defaults to True if connection to Hopsworks is established from external environment (e.g AWS
                 Sagemaker or Google Colab), otherwise to False.
             init_online_store_sql_client: bool, optional. If set to True, initialise the SQL client to retrieve feature vector(s)
-                from the online feature store. Defaults to True if init_online_.
+                from the online feature store. Defaults to True if init_online_store_rest_client is False, otherwise False.
             init_online_store_rest_client: bool, optional. If set to True, initialise the Online Store REST Client to retrieve
                 feature vector(s) from the online feature store. Defaults to False, meaning the sql client will be initialised.
             options: Additional options as key/value pairs for configuring online serving engine.
                 * key: kwargs of SqlAlchemy engine creation (See: https://docs.sqlalchemy.org/en/20/core/engines.html#sqlalchemy.create_engine).
                   For example: `{"pool_size": 10}`
                 * key: "config_online_store_rest_client" - dict, optional. Optional configuration options to override defaults for the Online Store REST Client.
                 * key: "reset_online_store_rest_client" - bool, optional. If set to True, the Online Store REST Client will be reset. Provide
-                    `config_online_store_rest_client` to override defaults.
+                    "config_online_store_rest_client" to override defaults.
         """
         # initiate batch scoring server
         # `training_dataset_version` should not be set if `None` otherwise backend will look up the td.

python/tests/core/test_vector_server.py

@@ -229,7 +229,7 @@ def test_rest_client_config_on_serving(
             inference_helper_columns=True,
             init_online_store_sql_client=False,
             init_online_store_rest_client=True,
-            options={"online_store_rest_config": optional_config},
+            options={"config_online_store_rest_client": optional_config},
         )
         batch_server.init_serving(
             entity=fv,
@@ -238,7 +238,7 @@ def test_rest_client_config_on_serving(
             inference_helper_columns=True,
             init_online_store_sql_client=False,
             init_online_store_rest_client=True,
-            options={"online_store_rest_config": optional_config},
+            options={"config_online_store_rest_client": optional_config},
         )
 
         print(init_online_store_rest_client.call_args_list)
@@ -256,12 +256,10 @@ def test_rest_client_config_on_serving(
             == optional_config
         )
         assert (
-            init_online_store_rest_client.call_args_list[0][1]["reset_connection"]
-            is False
+            init_online_store_rest_client.call_args_list[0][1]["reset_client"] is False
         )
         assert (
-            init_online_store_rest_client.call_args_list[1][1]["reset_connection"]
-            is False
+            init_online_store_rest_client.call_args_list[1][1]["reset_client"] is False
         )
 
     def test_reset_connection(