Graceful shutdown proxy hint feature

Hi,

With all the efforts done for the SaaS product, I assume there is a feature like this implemented in MariaDB already. Therefore I add this as a documentation request.

In Percona server, there is pxc_maint_mode. This indicates that proxies (MaxScale, ProxySQL) should gracefully stop sending traffic to this cluster node, or to this node when there are multiple nodes in this group.

Is there a corresponding variable in MariaDB, so that MaxScale or ProxySQL can gracefully remove traffic from the node in maintenance?

Thank you,