Logging stacktrace for all calls to EdxElasticsearchSearchBackend.setup()

LEARNER-2188

course_discovery/apps/edx_haystack_extensions/backends.py

+import logging
+import traceback
+
 from haystack.backends.elasticsearch_backend import ElasticsearchSearchBackend, ElasticsearchSearchEngine
 
 from course_discovery.apps.edx_haystack_extensions.elasticsearch_boost_config import get_elasticsearch_boost_config
 
+logger = logging.getLogger(__name__)
+
 
 class SimpleQuerySearchBackendMixin(object):
     """
@@ -128,6 +133,10 @@ class EdxElasticsearchSearchBackend(SimpleQuerySearchBackendMixin, NonClearingSe
 
         return super().search(query_string, **kwargs)
 
+    def setup(self):
+        logger.info('DEBUG: EdxElasticsearchSearchBackend.setup() called: %s', '\n'.join(traceback.format_stack()))
+        return super().setup()
+
 
 class EdxElasticsearchSearchEngine(ElasticsearchSearchEngine):
     backend = EdxElasticsearchSearchBackend