diff --git a/core/lib/Drupal/Core/Database/ReplicaKillSwitch.php b/core/lib/Drupal/Core/Database/ReplicaKillSwitch.php
index eaebef2c34..1140e220de 100644
--- a/core/lib/Drupal/Core/Database/ReplicaKillSwitch.php
+++ b/core/lib/Drupal/Core/Database/ReplicaKillSwitch.php
@@ -82,16 +82,16 @@ public function checkReplicaServer(GetResponseEvent $event) {
     // In Drupal's distributed database structure, new data is written to the
     // master and then propagated to the replica servers.  This means there is a
     // lag between when data is written to the master and when it is available
-    // on the replica. At these times, we will want to avoid using a replica server
-    // temporarily. For example, if a user posts a new node then we want to
-    // disable the replica server for that user temporarily to allow the replica
-    // server to catch up.
+    // on the replica. At these times, we will want to avoid using a replica
+    // server temporarily. For example, if a user posts a new node then we want
+    // to disable the replica server for that user temporarily to allow the
+    // replica server to catch up.
     // That way, that user will see their changes immediately while for other
     // users we still get the benefits of having a replica server, just with
-    // slightly stale data.  Code that wants to disable the replica server should
-    // use the db_set_ignore_replica() function to set
-    // $_SESSION['ignore_replica_server'] to the timestamp after which the replica
-    // can be re-enabled.
+    // slightly stale data. Code that wants to disable the replica server should
+    // use the 'database.replica_kill_switch' service's trigger() method to set
+    // 'ignore_replica_server' session flag to the timestamp after which the
+    // replica can be re-enabled.
     if ($this->session->has('ignore_replica_server')) {
       if ($this->session->get('ignore_replica_server') >= $this->time->getRequestTime()) {
         Database::ignoreTarget('default', 'replica');