Merge pull request #542 from XuPeng-SH/track_0.6.0

[skip ci](shards): fix db create engine typo and exception errors

shards/mishards/db_base.py

@@ -29,7 +29,7 @@ class DB:
             self.engine = create_engine(url)
         else:
             self.engine = create_engine(uri, pool_size=pool_size,
-                                        pool_recycle=pool_size,
+                                        pool_recycle=pool_recycle,
                                         pool_timeout=pool_timeout,
                                         pool_pre_ping=pool_pre_ping,
                                         echo=echo,

shards/mishards/exception_handlers.py

@@ -24,8 +24,11 @@ def resp_handler(err, error_code):
     if resp_class == milvus_pb2.VectorIds:
         return resp_class(status=status, vector_id_array=[])
 
-    if resp_class == milvus_pb2.TopKQueryResultList:
-        return resp_class(status=status, topk_query_result=[])
+    if resp_class == milvus_pb2.TopKQueryResult:
+        return resp_class(status=status,
+                          row_num=0,
+                          ids=[],
+                          distances=[])
 
     if resp_class == milvus_pb2.TableRowCount:
         return resp_class(status=status, table_row_count=-1)