A simple handy way it 

0. stop all mariadb containers

1. choose the last stopped node ( data may be loss if you choose a wrong node, but mostly, it doesn't matter)

2. change the /var/lib/docker/volumes/mariadb/_data/grastate.dat, safe_to_bootstrap: 1

3. change the /etc/kolla/mariadb/galera.cnf add

```

[mysqld]

wsrep_new_cluster=1

```

4. start the mariadb, and wait for it to become available.

5. start mariadb on other nodes

6. revert configuration on 3) and restart the first mariadb

On Tue, Nov 17, 2020 at 3:42 AM Radosław Piliszek <radoslaw.piliszek@gmail.com> wrote:

On Mon, Nov 16, 2020 at 11:33 AM Eddie Yen <missile0407@gmail.com> wrote:
>
> Hi yoctozepto, thanks your advice.
>
> Perhaps need to do maraidb_recovery again once the failure node back online to prevent brain split issue.
> But we'll try it if we met the same case again in the future!

I would simply eradicate the container and volume on it and then redeploy.
Less hassle, satisfaction guaranteed.

-yoctozepto