Add comment explaining why pre-start should always exit 0
@@ -39,6 +39,9 @@ pid_guard $PIDFILE $PROC_NAME
cd $MARIADB_CTRL_PACKAGE
+# Ignore failures during pre-start
+# The interruptor will prevent prestart from succeeding, and then galera-healthcheck will not be running.
+# The rejoin-unsafe errand only works on nodes that have a galera-healthcheck process running.
set +e
$MARIADB_CTRL_PREFIX_CMD \
"PATH=$PATH $MARIADB_CTRL_PACKAGE/bin/mariadb_ctrl-prestart \
