address comments

docs/install/upgrade.md

@@ -56,3 +56,8 @@ So, copying `notebook` and `conf` directory should be enough.
  - From 0.7, we uses `pegdown` as the `markdown.parser.type` option for the `%md` interpreter. Rendered markdown might be different from what you expected
  - From 0.7 note.json format has been changed to support multiple outputs in a paragraph. Zeppelin will automatically convert old format to new format. 0.6 or lower version can read new note.json format but output will not be displayed. For the detail, see [ZEPPELIN-212](http://issues.apache.org/jira/browse/ZEPPELIN-212) and [pull request](https://github.com/apache/zeppelin/pull/1658).
  - From 0.7 note storage layer will utilize `GitNotebookRepo` by default instead of `VFSNotebookRepo` storage layer, which is an extension of latter one with versioning capabilities on top of it.
+
+### Upgrading from Zeppelin 0.7 to 0.8
+
+ - From 0.8, we recommend to use `PYSPARK_PYTHON` and `PYSPARK_DRIVER_PYTHON` instead of `zeppelin.pyspark.python` as `zeppelin.pyspark.python` only effects driver. You can use `PYSPARK_PYTHON` and `PYSPARK_DRIVER_PYTHON` as using them in spark.
+ 

docs/interpreter/spark.md

@@ -106,7 +106,7 @@ You can also set other Spark properties which are not listed in the table. For a
   <tr>
     <td>PYSPARK_PYTHON</td>
     <td>python</td>
-    <td>Python binary executable to use for PySpark in both driver and workers (default is <code>python</code> if available, otherwise <code>python</code>).
+    <td>Python binary executable to use for PySpark in both driver and workers (default is <code>python</code>).
             Property <code>spark.pyspark.python</code> take precedence if it is set</td>
   </tr>
   <tr>