Cross version testing

* Bump down the version bound and convert the spark jobs into multi-dbr jobs

Author: NiallEgan

cmdexec/clients/python/src/databricks/sql/thrift_backend.py

@@ -284,9 +284,9 @@ def attempt_request(attempt):
     def _check_protocol_version(self, t_open_session_resp):
         protocol_version = t_open_session_resp.serverProtocolVersion
 
-        if protocol_version < ttypes.TProtocolVersion.SPARK_CLI_SERVICE_PROTOCOL_V3:
+        if protocol_version < ttypes.TProtocolVersion.SPARK_CLI_SERVICE_PROTOCOL_V2:
             raise OperationalError("Error: expected server to use a protocol version >= "
-                                   "SPARK_CLI_SERVICE_PROTOCOL_V3, "
+                                   "SPARK_CLI_SERVICE_PROTOCOL_V2, "
                                    "instead got: {}".format(protocol_version))
 
     def _check_initial_namespace(self, catalog, schema, response):

cmdexec/clients/python/tests/test_thrift_backend.py

@@ -108,7 +108,6 @@ def test_bad_protocol_versions_are_rejected(self, tcli_service_client_cass):
             ttypes.TProtocolVersion.HIVE_CLI_SERVICE_PROTOCOL_V9,
             ttypes.TProtocolVersion.HIVE_CLI_SERVICE_PROTOCOL_V10,
             ttypes.TProtocolVersion.SPARK_CLI_SERVICE_PROTOCOL_V1,
-            ttypes.TProtocolVersion.SPARK_CLI_SERVICE_PROTOCOL_V2,
         ]
 
         for protocol_version in bad_protocol_versions:
@@ -125,8 +124,9 @@ def test_bad_protocol_versions_are_rejected(self, tcli_service_client_cass):
     def test_okay_protocol_versions_succeed(self, tcli_service_client_cass):
         t_http_client_instance = tcli_service_client_cass.return_value
         good_protocol_versions = [
+            ttypes.TProtocolVersion.SPARK_CLI_SERVICE_PROTOCOL_V2,
             ttypes.TProtocolVersion.SPARK_CLI_SERVICE_PROTOCOL_V3,
-            ttypes.TProtocolVersion.SPARK_CLI_SERVICE_PROTOCOL_V4,
+            ttypes.TProtocolVersion.SPARK_CLI_SERVICE_PROTOCOL_V4
         ]
 
         for protocol_version in good_protocol_versions: