Replaced commented code with explanation

Author: ruebrenda

haystack/backends/elasticsearch_backend.py

@@ -189,8 +189,11 @@ def update(self, index, iterable, commit=True):
 
         bulk(self.conn, prepped_docs, index=self.index_name, doc_type='modelresult')
 
-        # if commit:
-        #     self.conn.indices.refresh(index=self.index_name)
+        # We are explicitly eliminating the call to self.conn.indices.refresh().
+        # ElasticSearch will do an automatic refresh once per minute. Manually invoking refresh
+        # on every update triggers 1000's of unnecessary API calls.
+        # The underlying issue is that neither SearchIndex.update nor SearchIndex.update_object
+        # pass kwargs to this method, so setting commit to False does not solve the problem.
 
     def remove(self, obj_or_string, commit=True):
         doc_id = get_identifier(obj_or_string)
@@ -209,8 +212,10 @@ def remove(self, obj_or_string, commit=True):
         try:
             self.conn.delete(index=self.index_name, doc_type='modelresult', id=doc_id, ignore=404)
 
-            # if commit:
-            #     self.conn.indices.refresh(index=self.index_name)
+            # We are explicitly eliminating the call to self.conn.indices.refresh().
+            # ElasticSearch will do an automatic refresh once per minute. Manually invoking refresh
+            # on every remove triggers 1000's of unnecessary API calls.
+
         except elasticsearch.TransportError as e:
             if not self.silently_fail:
                 raise