2 files changed, 15 insertions, 6 deletions
diff --git a/fatcat_scholar/search.py b/fatcat_scholar/search.py
index 2ae0ba9..e9f2bc8 100644
--- a/fatcat_scholar/search.py
+++ b/fatcat_scholar/search.py
@@ -417,16 +417,25 @@ def do_fulltext_search(
     )
 
 
-def es_scholar_index_exists() -> bool:
+def es_scholar_index_alive() -> bool:
     """
-    Checks if the configured back-end elasticsearch index exists.
-    Intended to be used in health checks.
+    Checks if the configured back-end elasticsearch index exists and can
+    service queries. Intended to be used in health checks.
+
+    Note that the regular client.indices.exists(index) function call will
+    return an error if the cluster leader can not be reached, even if the local
+    node could service queries in a read-only manner.
+
+    The client.indices.get_mapping(index) API, or the client.cat.count(index)
+    API, both return quickly and indicate that queries can be run against the
+    index.
     """
     try:
-        resp = es_client.indices.exists(settings.ELASTICSEARCH_QUERY_FULLTEXT_INDEX)
+        resp = es_client.indices.get_mapping(settings.ELASTICSEARCH_QUERY_FULLTEXT_INDEX)
     except elasticsearch.exceptions.RequestError as e_raw:
         if e_raw.status_code == 404:
             return False
         else:
             raise e_raw
     return resp
+
diff --git a/fatcat_scholar/web.py b/fatcat_scholar/web.py
index 6cda5b7..895af18 100644
--- a/fatcat_scholar/web.py
+++ b/fatcat_scholar/web.py
@@ -25,7 +25,7 @@ from fatcat_scholar.search import (
     process_query,
     FulltextQuery,
     FulltextHits,
-    es_scholar_index_exists,
+    es_scholar_index_alive,
 )
 from fatcat_scholar.schema import ScholarDoc
 
@@ -118,7 +118,7 @@ def health_get() -> Any:
     """
     Checks that connection back to elasticsearch index is working.
     """
-    if not es_scholar_index_exists():
+    if not es_scholar_index_alive():
         raise HTTPException(status_code=503)
     return Response()