diff --git a/server/message_cache.go b/server/message_cache.go
index 7eb37cf9..bce94220 100644
--- a/server/message_cache.go
+++ b/server/message_cache.go
@@ -313,7 +313,7 @@ func (c *messageCache) addMessages(ms []*message) error {
 		}
 	}
 	if err := tx.Commit(); err != nil {
-		log.Warn("Cache: Writing %d message(s) failed (took %v)", len(ms), time.Since(start))
+		log.Error("Cache: Writing %d message(s) failed (took %v)", len(ms), time.Since(start))
 		return err
 	}
 	log.Debug("Cache: Wrote %d message(s) in %v", len(ms), time.Since(start))
diff --git a/server/server.yml b/server/server.yml
index 4b08129b..1b268995 100644
--- a/server/server.yml
+++ b/server/server.yml
@@ -53,6 +53,12 @@
 #       pragma journal_mode = WAL;
 #       pragma synchronous = normal;
 #       pragma temp_store = memory;
+#       pragma busy_timeout = 15000;
+#       vacuum;
+#
+# The "cache-batch-size" and "cache-batch-timeout" parameter allow enabling async batch writing
+# of messages. If set, messages will be queued and written to the database in batches of the given
+# size, or after the given timeout. This is only required for high volume servers.
 #
 # Debian/RPM package users:
 #   Use /var/cache/ntfy/cache.db as cache file to avoid permission issues. The package